# Tips for Installing a Dust Collection System



## Router Forums (May 7, 2010)

> There's no way around it: wood dust is a health hazard. Multiple health agencies have classified wood dust as a carcinogen. As a woodworker, whether professionally or as a hobbyist, safety should be the top priority -- even ahead of creating a quality product. This is where dust collection systems come in - the name is pretty straightforward for their purpose: they collect the dust that can harm your lungs and cause health problems later down the road. *Dust Collection*


Read more *here*:
http://www.routerforums.com/articles/tips-for-installing-a-dust-collection-system/


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## Admin (Feb 13, 2012)

Feel free to respond with effective methods that you have found for dust collection or anything you would do differently.

Share pictures of your dust collection system! :smile:


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## RainMan 2.0 (May 6, 2014)

This is perfect timing as I recently added a sander and relocated my dust collector . I need to find out which way would be best to plump the machinery . I'm assuming 4" ABS and waste gates but I'll post a pic and see what the experts have to say


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## subtleaccents (Nov 5, 2011)

While the plastic duct system is more air tight (less leakage) it has the highest chances of sustaining static. Plastic dust must have a good grounding system attached to every foot of it. Inside the plastic ducting is the most efficient. I used metal ducting to eliminate the need for a ground wire along the entire length of the system. Beside the ground wire from the motor to the electric supply I have an external ground from the dust collector to the grounding rod that is used for the electric panel located outside the building. Being an ex USCG Damage Control (Fire Fighter) I cannot be safe enough from fire hazard, especially when we were out at sea.


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## DaninVan (Jan 1, 2012)

JT; I'd be very surprised if putting the Copper ground wire on the _outside_ of the PVC piping would be effective. My understanding was that it needed to be on the interior where of course it brings up other problems.


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## TwoSkies57 (Feb 23, 2009)

Static discharge from a dust collection system has always seemed to me to be a bunch of hooey!!! I've never noticed enough static in my system to even consider it being a potential problem. That is not to say it wasn't there, I just never noticed it.................until!!!! Recently hooked up a Dewalt 735 planer. (an outstanding piece of equipment by the way). While running the first few board thru the new planer, I would reach around to grab the board as it exited the machine. I'm telling you what.. from 6"s away, there was enough static to make the hair on my arms stand on end!!! I will now incorporate some sort of grounding medium into my system.


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## tvman44 (Jun 25, 2013)

My DC system is 4" PVC no grounding and I have never noticed any static problems. As for the DW735 you shouldn't be having a problem there if the electrical supply to the planer is properly grounded because that grounds the metal body of the planer. I recently got a DW735 and again not noticed any problems.


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## RainMan 2.0 (May 6, 2014)

Guys I've heard of grounding but never bothered . No incidents yet but I was using the hose to pick up dust off the floor and for the first time I noticed the hair standing up on my arm . Made me wonder :|


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## Cherryville Chuck (Sep 28, 2010)

I also question the idea of grounding the outside of a plastic pipe. The plastic piping systems I've seen advertised suggest running a wire down the inside and drilling a hole through near a connection so you can attach the inside to a bolt and another wire to the bolt on the outside. My preference was to use galvanized ducting instead. It's cheap and easier to ground. I still used the bolt idea but no wire needed on the inside. I also still used plastic ducting at the corners instead of galvanized bends. The plastic ones are much smoother. Use the aluminum foil duct tape at all joints and it works just as well.


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## Cherryville Chuck (Sep 28, 2010)

RainMan1 said:


> Guys I've heard of grounding but never bothered . No incidents yet but I was using the hose to pick up dust off the floor and for the first time I noticed the hair standing up on my arm . Made me wonder :|


Why take a chance? Very little effort and cost are required to avoid that potential problem. If static did cause a fire, the results would likely be catastrophic from your point of view.


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## RainMan 2.0 (May 6, 2014)

Cherryville Chuck said:


> Why take a chance? Very little effort and cost are required to avoid that potential problem. If static did cause a fire, the results would likely be catastrophic from your point of view.


I never thought about the potential for fire , I was told at Winsor Plywood that you could get a lethal shock .
I have no issues grounding it , I just haven't got around to it l but if I start plumbing this correctly I would like to do it right


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## BernieW (Sep 12, 2006)

I to had never grounded my DC but after getting a pretty good static shock I run a bare copper wire inside my PVC and aluminum tape wrapped around the outside about 3" apart running the length of the pipe. The inside wire and outside tape are connected together with a screw and from the screw to electrical ground. I did a lot of reading of Dr. Rod Cole on grounding PVC. Not sure if it is right or wrong but I have never had my hair stand up on my arms or got a static shock again.


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## schnewj (Nov 18, 2013)

This link might help with understanding and methodology of the grounding of plastic pipe.

Everyone has to understand a couple of basics; any time you have air flow across a surface, you will build static, moisture (humidity) contributes to the control or generation of static.

With all that being said, I have never seen or heard of any definitive evidence of a fire starting in a hobbyist type wood shop environment, which was caused by a static discharge in a dust collection system. If anyone has such evidence I would like the details for my own edification.

In my opinion (as a safety professional for over 35 years) I do not see it as the huge danger that some folks claim it to be. However, the grounding of ducting, even PVC is not that difficult to do. So why not do it?

Is there a danger? Static can always be an issue in a fine dust environment (look at grain silo explosions). Is it prevalent in a hobbyist wood shop? Probably not.

I think the real issue in not the grounding of ducting to prevent an explosion, but more of preventing a static discharge shock that might result in an unintended reaction by an individual. The use of volatiles near a static source is always a paramount hazard. 

I'd be interested in hearing from some EE types, if there are any out there, or anyone familiar with the installation of commercial duct systems, as to what their opinion is on the matter.

Bill


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## RainMan 2.0 (May 6, 2014)

Bill I was debating to connect a ground wire from a ground rod to the duct . I'm not sure if what that guy did was neccesary ? 

Or a guy could go from an electrical outlets box to the duct as all your electrical boxes are grounded by code


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## schnewj (Nov 18, 2013)

RainMan1 said:


> Bill I was debating to connect a ground wire from a ground rod to the duct . I'm not sure if what that guy did was neccesary ?
> 
> Or a guy could go from an electrical outlets box to the duct as all your electrical boxes are grounded by code


I basically agree that extensive grounding may not be necessary. However, why not ground the system. 

As far as grounding goes, you are right! If you ground to your electrical system it would go to the buss bar and to the ground rod. Some may say that it may not be a good idea, but I'm not sure that it is against NEC codes. Your electrical codes may be different in Canada. 

I have all of my reference books packed away in storage so I can't research the codes requirements.

Bill


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## sunnybob (Apr 3, 2015)

Cherryville Chuck said:


> I also question the idea of grounding the outside of a plastic pipe. The plastic piping systems I've seen advertised suggest running a wire down the inside and drilling a hole through near a connection so you can attach the inside to a bolt and another wire to the bolt on the outside. My preference was to use galvanized ducting instead. It's cheap and easier to ground. I still used the bolt idea but no wire needed on the inside. I also still used plastic ducting at the corners instead of galvanized bends. The plastic ones are much smoother. Use the aluminum foil duct tape at all joints and it works just as well.


Dont rely on foil tape as an electrical connection. Each layer of tape has a non conductive layer of glue on the underside. If you make several turns of foil tape what you have built is a capacitor, which actually stores and multiplies electricity. A well wrapped foil joint is a much greater hazard than an unwrapped joint.

Each plastic elbow acts as an isolator unless there is a metal connection between each cuff so every section of pipe between each elbow needs to be wired together, and to then to ground preferably at each end.
The only 100% way of curing that problem would be to drill a hole through each cuff (and tube) and bolt each together with an earth bonding wire. Which would play havoc with your air stream :crying:


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## Mike (Nov 22, 2004)

Opinions vary on the need for dissipating static electricity in home dust collection equipment. I have yet to see a shop vacuum with a static grounding feature. Neither of my dust collectors came with a static grounding system. As far as dust separators go Oneida includes a static grounding kit while Clear Vue Cyclones and Rockler do not. Festool is now offering anti static hose as an option to use with their vacuums.

Grounding the static is easy; look at the Dust Deputy Deluxe in the photo to see how this is done. Metallic tape, some wire and a washer is all that is required. As long as your separator is sitting on the ground I do not think this is really needed.

More to follow on this soon.


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## Herb Stoops (Aug 28, 2012)

I just put a bare copper #12 wire from my machine to the DC pipe. The machine is grounded so it grounds the pipe. I don't run copper along the pipe,and especially inside as it keeps the chips from moving smoothly thru the PVC and can cause build up that cuts your air flow. I only do it to keep from getting shocked at the planer and drum sander.
Herb


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## sunnybob (Apr 3, 2015)

schnewj said:


> https://www.youtube.com/watch?v=sCPiu0zQwyI
> 
> This link might help with understanding and methodology of the grounding of plastic pipe.
> 
> ...


I have a couple of quite major issues with that video.
I have been a mechanical engineer in commercial catering installations for 20 years, and part of that job involved earth continuity installing and testing. Admittedly this was in the UK, and I know the USA has some variations of regulations, but even so, nobody can say the UK is backward in safety regs.:nerd:

The first issue is he is advocating a certain type of wire crimp tool that does not meet safety regulations any where in Europe. 

The ratchet crimp as in this pic
https://www.google.com.cy/search?q=...Wire_end_Ferrules_Crimping_Tools.html;450;314 
is far safer, giving a consistant pressure on each use. the thin model used by the guy will give wildly varying pressures according to who uses it. Arnie would cut the crimp in two, a person with arthritis for instance will make a joint that is not secure, and unsecure joints are a big cause of sparking.
The ratchet crimp will only release when the correct pressure has been applied, even if that means a frail person has to use two hands, or even lean it against the bench, but at least you know every joint is consistantly good.

My main concern is the BARE metal wire he is using. I repeat, BARE metal! he is attempting to stop static sparks by looping BARE metal all across the place? He's not insulating the equipment, he's radiating the static.

If the wire was loaded with static and anything metallic was passed anywhere near that bare wire, he would soon learn about static sparks.

Standard household insulated ground wire should be used everywhere on a small earth continuity circuit. If anyone wants to test its efficiency, use a multitester set to Ohms, and check between any of the connections to a known ground. The power socket ground will be enough. While youre there, test your equipment metal case to the same ground screw. Hell, test everything! >We tested to achieve LESS than 0.2 ohms. 

A Quick point here for people not used this kind of test on a multimeter, first put the two leads together and measure the resistance of the machine and leads themselves. Its possible to get a reading of 0.6 or so from the machine depending on quality, and this number can vary every single time you use the tester.
So, when making the real test, you should check the machine EVERY TIME. Then when you test you should see the original number plus no more than another 0.2. So in this example, if you got 0.6 from the tester, and then checked the installation, If you got more than 0.8, that would be bad.

(1 decimal point either way would be regarded as fluctuation on a cheap tester, if you got more than 3 decimal points you should be worried)
If you want to be really anal about it, test between every connection on the run, and the run to ground at both ends. 
Again, if your leads arent long enough, you can use extra wire to wrap around the test leads to reach, but you must make the self check again before testing the installation.

If you do not achieve these numbers then my advice is to go over the entire installation checking until you do. Or get a QUALIFIED electrician in, not a mate who has done "a bit of that".

Hope this helps.


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## Cherryville Chuck (Sep 28, 2010)

sunnybob said:


> Dont rely on foil tape as an electrical connection. Each layer of tape has a non conductive layer of glue on the underside. If you make several turns of foil tape what you have built is a capacitor, which actually stores and multiplies electricity. A well wrapped foil joint is a much greater hazard than an unwrapped joint.
> 
> Each plastic elbow acts as an isolator unless there is a metal connection between each cuff so every section of pipe between each elbow needs to be wired together, and to then to ground preferably at each end.
> The only 100% way of curing that problem would be to drill a hole through each cuff (and tube) and bolt each together with an earth bonding wire. Which would play havoc with your air stream :crying:


The foil tape was to prevent air leakage. Since one section slips into the next section (under the tape) grounding is not affected. If you are really concerned about air leakage also apply the tape along the linear seam. If you do that there is guaranteed no difference in performance between plastic and metal pipe.


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## sunnybob (Apr 3, 2015)

out of curiosity, I have just gone to the workshop and conducted a quick experiment with foil tape.

This is obviously a spur of the moment test, but the results surprised even me.

Using my test meter on a metal paintbrush section I got the following results.
meter leads test to 0.3 ohm.
metal paintbrush body tests to 0.3 ohm (perfect, as I would expect as the leads are only two inches apart)
single layer of foil under one test lead tests to 0.3 ohm (perfect, no loss)
double layer foil tests to 0.4 ohm (not so good, a significant loss of continuity)
triple layer foil tests to wildly varying numbers right up to infinity that would be an instant fail on any installation I have ever tested.

Conclusions; do NOT use foil tape in any area regarded as electrically sensitive unless you make sure there is no more than 1 complete turn of tape to stop the draught.
More than three turns would be a capacitor because the glue is storing the electric


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## DaninVan (Jan 1, 2012)

Speaking of conductor fails...
http://2.bp.blogspot.com/-lNOQFRPW5kk/VYbQWaRrxnI/AAAAAAAAnHA/irT04zSIJQg/s1600/Hit.gif


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## Cherryville Chuck (Sep 28, 2010)

sunnybob said:


> out of curiosity, I have just gone to the workshop and conducted a quick experiment with foil tape.
> 
> This is obviously a spur of the moment test, but the results surprised even me.
> 
> ...


Bob your measurements of the continuity of layer after layer of tape I'm sure are correct, especially if the layers were separated from each other as opposed to a continuous loop 3 layers thick, but the end of one pipe is crimped so that it will slide into the end of the next pipe. There is approximately 2" of overlap between the two. The tape only prevents suction loss. It has no effect on the continuity of current from one pipe to the next. It would be a factor if you were grounding from the outside layer of the tape.


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## sunnybob (Apr 3, 2015)

granted under those circumstances. What concerned me was the use of plastic elbows which are non conducting.
If you have a grounded metal tube sealed into a plastic elbow with foil tape, the plastic elbow disconnects each section from each other. Under those circumstances, a metal conductor should be used to bridge the plastic elbow and re connect with the next metallic section and not rely on a piece of foil tape to do the job.

But it is worth bearing in mind the capacitor effect, and not winding the foil tape around more than is absolutely neccessary to seal the tube (1 turn)

I originally had 4" metal for my dust collection system, small as it is, but the cost of fitting 5 blast gates (1 for for each appliance) turned me to a smaller, 63mm clear plastic tube and elbows with blast gates for each. Still not cheap, but a much nicer appearance and more space behind the machines. 

Until now, I had not considered static a problem on my system. I still think the risk is extremely low for me, where the system doesnt run all day, and I am quite paranoid about using the floor vac at the end of each day, sometimes twice if theres been a lot of activity (sawdust in the house is a BIG BIG issue!!!), but I shall study the problem, and may well end up earthing the tubing


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## sunnybob (Apr 3, 2015)

well, I've studied my system, and i dont think there is any point in adding ground wiring to it.
Its only a 12 ft long run, with 5 outlets. Theres a cyclone (all plastic) at the end of the run between the tube and the vacuum unit, which also has an air filter between the void and the electric motor.
the plastic cyclone feeds dust down into a sealed plastic bucket. Plastic flexible hose connects everything to everything. Although there are metal clips holding the pipe to the wall, they are held with screws into plastic plugs. there are even wooden spacer blocks behind each clip.

So, theres no way any mains electricity can reach any part of the system or travel along it. Any static could only come from inside the pipe itself, and the travelling time of the dust moving 12 ft is just not measurable. I dont believe it would be possible for enough friction to form to produce any static.
I think I'm good to go. (G)


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## Stick486 (Jan 4, 2013)

simplify the thought process...

every place there is combustible dust static electricity is an issue....
the possibility exists...
choose to blow it off, ignore it, gamble, play chicken (w/ yours and other's) w/ life, limb and propertybelieve ''not me,'' or it's all just rhetoric and if the day ''should'' arrive enjoy the I tol'ja so's...

https://www.osha.gov/dsg/combustibledust/index.html
https://www.osha.gov/dts/shib/shib073105.html
NFPA 652: Standard on Combustible Dusts

A wide variety of materials that can be explosible in dust form exist in many industries. Examples of these materials include: food (e.g., candy, sugar, spice, starch, flour, feed), grain, tobacco, plastics, *wood*, paper, pulp, rubber, pesticides, pharmaceuticals, dyes, coal, metals (e.g., aluminum, chromium, iron, magnesium, and zinc). These materials are used in a wide range of industries and processes, such as agriculture, chemical manufacturing, pharmaceutical production, furniture, textiles, fossil fuel power generation, recycling operations, and and metal working and processing which includes additive manufacturing and 3D printing.


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## schnewj (Nov 18, 2013)

Stick486 said:


> simplify the thought process...
> 
> every place there is combustible dust static electricity is an issue....
> the possibility exists...
> ...


Stick,

It's not that I'm disagreeing with anything you have said, and I agree with "belts and suspenders" in this case. However, The real danger of explosions is evident in commercial operations where the use of the dust systems is a continuous operation. The possibilities of static discharge are probable and possible.

However, in a hobby or small shop operation where continuous operations are unlikely the probabilities of a static event are very low.

I have never, in all of my research, ever come across a documented event in a small workshop that caused a fire or explosion due to static discharge in the ducting. I am not saying that there aren't any but I have never found a credible documented case.

That is why in my first post I asked if anyone who has knowledge of such an event to provide me with the details.

I spent 30 years of a much longer career as Safety Engineer for a large aerospace company. My first assignment was to oversee the construction, testing and operations of a building that had a self contained "Mix Room" and three spray cells.

We sprayed primer on a 27 foot by 100+ foot Aluminum tank and then coated it with a cork based mixture in a heptane slurry. 

The mix room is where the slurry was made. 

We dealt with Heptane, Toluene, Alcohol, and Methyl Ethyl Ketone in the processes. Needless to say, grounding and static was a big issue, right down to the non-conductive flooring and the use of wrist stats for static.

We never had an incident and thank God we eventually did away with the some of the processes.

My point to the ramble is that I have extensive experience in grounding and the techniques involved. Sonnybob is astute in his observations, but for a hobby shop I just don't see a high level of concern over static in the dust system. 

I would, personally ground my own systems, but not for the fear of a static discharge fire and certainly not an explosion, but to keep from getting my fingers zapped.

Bottom line, ground the system, it's not "rocket science", if anything it will keep you from getting zapped when you get near the ducts or machinery.

Bill


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## Stick486 (Jan 4, 2013)

I worked in the R&D department of an explosives/munitions facility for a number of years... 
not to mention the years of grain mill work... (millwright)
static being an issue is a very real thing...

as long as static is an issue.. would it be be prudent to cover your butt...
single digit humidity here enlarges the issues...
even if there are no fire/explosions, static discharges to a person get to be very annoying... 
forbid if you should be wearing a pacemaker...

preventative medicine here goes a long ways...
doesn't take much to accomplish either...
ask Ray what it was like when got a shock and his hearing aide went nuts...
his screams were something else...


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## schnewj (Nov 18, 2013)

Stick486 said:


> preventative medicine here goes a long ways...doesn't take much to accomplish either...
> ask Ray what it was like when got a shock and his hearing aide went nuts...his screams were something else...


Exactly the reason(s) that I advocate doing it (LOL). However, in a small wood shop I still don't believe that not grounding the ducting is a fire or explosion waiting to happen. 

Working as a millwright and especially in the explosives field speaks volumes on your expertise on grounding and static. I dealt with low order ordinance in my job and we were extremely careful about grounding and static discharges. I can only imagine what it was like in the munitions operations.

Bill


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## Stick486 (Jan 4, 2013)

schnewj said:


> Exactly the reason(s) that I advocate doing it (LOL). However, in a small wood shop I still don't believe that not grounding the ducting is a fire or explosion waiting to happen.
> 
> I can only imagine what it was like in the munitions operations.
> 
> Bill


so no sweat on the fire and explosions... protect the people/children in the shop... but do something about it...
I would not want to be party to screwing up somebody's pacemaker..
the drier the air the more it's an issue...

Ray was in a itty bitty shop...
one worker and 4 audience.. and it wasn't Ray that was working but his screams, him hitting the floor and grabbing his head sure got our adrenaline pumping... 
apparently the static shock caused some kind of feed back in the hearing aide.. *WHEW!!!*

I built the assembly stations people used...
at 1st it was brute force defense.. major not so good...
next it was deflection.. better but there were some very serious issues...
then it became redirect, deflect and absorption.... got pretty good at it... earned some very nice bonuses and rate increases...
incident rate dropped to about ziltch...

the cool part of the job was to build a station.. custom make an explosive charge for it and go blow it up...
successes were treated to still larger charges to find it's limits... some of those explosions were spectacular....
failures were analyzed and re-engineered and run through the gambit...
building drying kilns, ovens and storage bunkers were another trip...
came pretty proficient at air and air over hydraulic systems... SS heat exchangers. radiant heat, air drying and a few other odds and ends.....


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## schnewj (Nov 18, 2013)

Stick486 said:


> the cool part of the job was to build a station.. custom make an explosive charge for it and go blow it up...
> successes were treated to still larger charges to find it's limits... some of those explosions were spectacular....
> failures were analyzed and re-engineered and run through the gambit...
> building drying kilns, ovens and storage bunkers were another trip...
> came pretty proficient at air and air over hydraulic systems... SS heat exchangers. radiant heat, air drying and a few other odds and ends.....


Who says, your job can't be fun!? I would have loved to do that kind of project.

Bill


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## sunnybob (Apr 3, 2015)

Stick486 said:


> the drier the air the more it's an issue...
> 
> ..


another reason Im ok. I live on an island, and its a very rare day indeed when the humidity drops below 50% .
75 plus is the norm. (lol)


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## Stick486 (Jan 4, 2013)

A buddy of mine had a contract to build specialized shipping containers for them and when he fell behind I helped him...
after a marathon building session we both took them out to the plant... 2 trucks two trailers...
so as we waited for the crates to be inspected/accepted two guys walked and wanted to know what I was doing... 
holding this stool down watching those two guys spin their wheels building what ever it is they're building...

spoke what I saw...
spoke what I thought...
ended leaving there w/ 10 tables and 5 times the material needed for the build...came back a week later w/ 10 slightly differently constructed prototypes....
they got tested...
I got paid...
and it was hit the ground running there after...

w/ jigs, different fastener regime, lighter materials and standardization I reduced build time from 32 man hours to 10 not to mention cut material costs by 40%...
not to mention a way better table...
f you hurried a base table happened in 7 man hours....

back then *rated* polycarbonate in 3x5 sheets depending on thicknesses was 3 - 8,000 $$$ a sheet...


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## Herb Stoops (Aug 28, 2012)

My response to all of this is a BIG TO DO over a non issue, I read a study awhile back when building my first system that an engineer did , He stated that the dust to oxygen levels in a home shop DC systems were no where near high enough or long enough duration to cause an explosion. And that it was a waste of time to run a bare copper wire inside or outside the ducts as the static electricity is formed on the inside walls of the duct work and the wire would be useless and would cause restriction especially at the elbow where material could catch on the connectors, Further since shocking is a nuisance a wire can be run from the machine which is grounded and attached to the duct thus eliminating any shock to the operator.

Herb


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## sunnybob (Apr 3, 2015)

Its always worth bringing potential safety issues to the attention of people, but each person has to make their own risk assessment, based on their particular circumstances. I would not sneer at any one who made a proper job of grounding the pipe (NOT BARE WIRE!), but i will not be doing mine.
But I would like to make one more mention of a post here. One person said he got a static shock from his machine when leaning across it. Thats a VERY BAD thing. I suspect that machine does not have a ground connection.
Using my explanation of testing resistance with a multitester, Every body should test each of their machines from the metal body to the building ground. Obviously any 2 wire double insulated tools are exempt from this.
I have seen many poor grounds on equipment, all of them potentially life threatening.
For any one man or very small shop, ground (or earth continuity) testing is far more important than static grounding.


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## Herb Stoops (Aug 28, 2012)

I have a perfectly grounded electrical system in my shop,and when I plug in my machine which has the proper ground plug from the factory, I feel that I am safe. I have no expertise to test all things electrical to see if they are grounded. I am a woodworker not an electrician and have a multimeter and don't know what any of those symbols on it mean anyway. All I know is that the needle wiggles and the sparks fly and then it doesn't work anymore so i have to throw it in the garbage.

As far as reaching over a machine and getting a shock of static E , has nothing to do with the grounding of the mach. It has happened to me numerous times on my drum sander and planer until I ran a wire from the duct to the machine to ground the plastic ductwork and give the static E a way to the ground.

Herb


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## sunnybob (Apr 3, 2015)

Herb Stoops said:


> I have a perfectly grounded electrical system in my shop,and when I plug in my machine which has the proper ground plug from the factory, I feel that I am safe. I have no expertise to test all things electrical to see if they are grounded. I am a woodworker not an electrician and have a multimeter and don't know what any of those symbols on it mean anyway. All I know is that the needle wiggles and the sparks fly and then it doesn't work anymore so i have to throw it in the garbage.
> 
> As far as reaching over a machine and getting a shock of static E , has nothing to do with the grounding of the mach. It has happened to me numerous times on my drum sander and planer until I ran a wire from the duct to the machine to ground the plastic ductwork and give the static E a way to the ground.
> 
> Herb


No offense intended in any of my posts, but I do advise you to check with the tester. As I said, in my working life I came across several (many) wiring situations that the operator was completely unaware of but were lethal. I even had to shut down an entire school kitchen once, leaving a couple hundred kids without dinner, but that was better than a chef getting killed.
On your tester there will be a greek omega symbol, like an upside down horseshoe. Thats Ohms. Its used to test any wiring circuits continuity. It might be the type that just beeps, thats no good for this testing, you need digital numbers.
Set it to ohms and put the leads together, if you get a number around zero point 6, then thats your base number. put one test point against any bare metal on your machine, and the other test point on a ground connection anywhere in the shop (not the same machine!). if the number goes higher than zero point (your base number plus another zero point three) then you need to check it out. If the number goes above 1.00 then stop using the machine untill its checked.

Or, you could just stop wearing the nylon underpants :surprise:>:laugh2:


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## Herb Stoops (Aug 28, 2012)

Thanks Bob, I still am not totally clear, "on a ground connection" is that like the ground point on the electrical receptacle that the motor is plugged into? And also do you do this test while the machine is running or plugged in and shut off? 

Thank you for taking the time to explain this.

Herb


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## sunnybob (Apr 3, 2015)

I have to be a bit vague on details. I'm English, and all my experience is with UK systems.

All earth testing can be carried out while a machine is operating, but its much safer to shut it off.

So I'll do my best, I'll start right at the beginning as I have no idea what you do or dont know about electric.
All of your electrical equipment indoors and at work, has either two wires (double insulated, and not relevant to anything here).
three wires (medium powered stuff that plugs into a socket)
or more than three (could be 4 or five wires, this is known as 3 phase, and its heavy machinery or big ovens usually hard wired or with huge plugs) Only relevant here if it has a known earth wire.
anything in Europe that has more than two wires uses one of them as a ground (we call it earth) wire. The usa sometimes uses a system that does not have an earth wire known as delta wiring. This is not covered in my tutorial (g).
So what I'm talking about here is everything that plugs into a wall socket and can be disconnected just by pulling the plug out and has three wires.

In the UK and Europe, that earth wire is green /yellow. I really dont know what USA uses, find out, its important.
The machines will run fine without an earth, its there purely to save your life.
If anything goes wrong inside the machine and the frame becomes live, the earth shorts that power to ground, and the fuse / trip blows.

Sometimes a motor inside the machine can cause static build up. If the machine is not fully earthed, that static can eventually build up and spark just like a car spark plug. The more static, the bigger the jump.

So, this is why I go on a bit about testing the earth. Visual check is NOT GOOD ENOUGH. I've seen wires that look perfect, and are broken inside the insulation.

The digital meter measures the resistance through the circuit. Its possible to have a circuit, but with corroded or loose connections that will not operate correctly.

If there is too much resistance, the excess electricity does not travel fast enough, and then theres trouble brewing.

So, getting back to the point. you need to make sure not only that the earth (ground) wire is connected, but that it is connected well enough to save your life.

This is where the numbers come in. What you have to do is put one end of the test leads FIRMLY onto a bare metal section of the machine (paint, grease, corrosion, rust, even dust will make the connection erratic).
Find the wall outlet and find the earth pin.(this is where I'm vague, i believe its a little metal piece on the outer edge of the circular socket)
Press the other test lead FIRMLY onto the earth pin . Make sure the socket is turned off for safety.

What youve done is now made your own circuit, through the meter and the earth wire to the machine. If the earth wire to the machine is faulty, you will get a big number, anything right up to infinity.
You should get a very low reading. the circuit itself should be in the zero point 2 (0.2 OHM) area. But this is where I told you to put the leads together first. All test meters have their own resistance inside, the better the meter the lower the resistance, and you need to know that number before you measure your wire.

using the example I gave, put the leads together and you might get 0.6 on the scale. so, measure the machine to the wall outlet, you should get around 0.8. Its worth noting that the numbers may vary a little bit as you look at them, but the same rule applies.

If you get anything bigger than 0.5 ohm plus your test meter number (that would be 1.1 in my example) you should get the wiring checked. The bigger the number, the more scared you should be.

You can do this test all over your house as well. If its an old house, you might get scared there as well (lol) I have found sockets in kitchens that have NO earth connection,. where sockets either side have been fine. Just use your test meter and wander around, checking earth pin to earth pin. You should get the same low numbers everywhere.
This test is especially important on electric showers where you are wet, inside a wet box, and the power is only a few mm away. Nobody survives a shower shock.
Not much to do with woodworking I know, but I feel its very important because you very rarely get over an electric shock, even a minor one.


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## Daikusan (Apr 12, 2013)

*DC Efficiency*

The thread more or less turned into ranging views on static electricity and grounding. Many interesting honest point were brought up. *BUT *disappointingly the efficiency of the actual dust removal subject was barely broached :crying:. A subject we all should be highly interested in.

When doing research on DC systems I ran across this link Dust collection for the small woodworking shop - SoloWoodworker

I believe many of Charles’ observations are right-on and are provocative for thinking. I particularly enjoyed the information in his sidebar titled _The Battle of the Titans_. He also preaches the same safety tips I see Mike, James, Harry, Chuck, and others ping on all the time (respirators, hearing protection, etc.). 

Charles made several important points such as a DC picking up metal (think screws and nails) and hitting the fan (anything hitting the fan, wood chips included, is dangerous -- in particular aluminum impellers). Hits can cause failure of the fan/impeller or in the case of metal, sparking a fire that could smolder (think static here also, even though unlikely.) It’s the unlikely things that get us in trouble:surprise:. 

Since I am a detail nut, I ended up at Bill Pentz website Dust Collection Research - Home I found his information technical and detailed. His overview is great. The other pages are deep and technical. They provide ideas many woodworkers do not consider. He also provides detailed plans for building your own DC system. *AND *he does discuss static.

I can recommend reading both sites if you are interested in DC systems.:yes4:


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## Cherryville Chuck (Sep 28, 2010)

Stick486 said:


> I worked in the R&D department of an explosives/munitions facility for a number of years...
> not to mention the years of grain mill work... (millwright)
> static being an issue is a very real thing...
> 
> ...


2 or 3 winters ago we had explosions at 2 sawmills here in BC that killed workers at each one. Fine dust is the number one suspect in both explosions. Most of the mills in the BC Interior are sawing high volumes of beetle killed pine and there is more dust produced than normal and the dust is much drier than normal as it is being produced.

This type accident (fire or explosion) is like coming into contact with a cutting tool, the results are often catastrophic. Grounding a system takes about an hour, give or take, and costs $10 or less. If you have a bunch of old speaker wire or lamp cord you can use that and it will cost nothing. Under those circumstances why wouldn't you do it?


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## Stick486 (Jan 4, 2013)

Cherryville Chuck said:


> Under those circumstances why wouldn't you do it?


beats the snot outta me...

asked the doc Friday about static electricity, pace makers. hearing aids, insulin pumps and any other other attached gizmo to the body...
w/o so much as blink the answer was yes.. static electricity can cause any where's from nothing to a trip to the morgue in not set right in time... (that Q got a rant about equipment, it's source and and and and.. WHEW)
why gamble...


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## sunnybob (Apr 3, 2015)

yeah, we got sidetracked a bit, but I think the safety alert is a good thing. Static is just another form of electricity, so good grounding on all equipment (household as well) makes it much harder for static to be a problem.

When you look at the first video link in this thread, at how hard and long he had to rub that plastic pipe, just to pick up the tiniest paper scraps, let alone make a spark. I think the risk on a one man hobby shop equipment is below minimal.
A big shop with the system running all day, thats different.


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## RainMan 2.0 (May 6, 2014)

I gotta say one thing guys , I should make a dust collection system for my miter saw as its my biggest dust offender right now . I've seen guys make wooden hoods/funnel that go in behind to catch most of it . It's kind of a pain because if you miter something 45 degrees the system has to still work so the hood usually ends up being large . 
Yet another project on the to do list


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## timbertailor (Oct 4, 2009)

No offense to the original poster of this thread but how can you talk about dust collection without discussing flow limits, filter limits, and emphasizing how important it is to upgrade your filters to prevent your system from being a fine particulate dust generator. That is a the real danger of a dust collection system and one that is not using a 1 or 0.5 micron filter with the flow capacity to maintain the flow guidelines mentioned in the article is more of a hazard than a safeguard.


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## sunnybob (Apr 3, 2015)

RainMan1 said:


> I gotta say one thing guys , I should make a dust collection system for my miter saw as its my biggest dust offender right now . I've seen guys make wooden hoods/funnel that go in behind to catch most of it . It's kind of a pain because if you miter something 45 degrees the system has to still work so the hood usually ends up being large .
> Yet another project on the to do list


does it not have a dust port?
I have a mitre saw /table saw combo, with 2 dust ports (connected to my extraction system) it catches a very large proportion of the dust. But I still wear a mask if I'm cutting more than a very small cut.


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## RainMan 2.0 (May 6, 2014)

sunnybob said:


> does it not have a dust port?
> I have a mitre saw /table saw combo, with 2 dust ports (connected to my extraction system) it catches a very large proportion of the dust. But I still wear a mask if I'm cutting more than a very small cut.


Yes it's a makita and I was thinking the same thing , remove the bag and put a hose onto its outlet . That would get a lot I suspect . A shroud would get more maybe yet? I'll have to fo a test and see if I cam justify a shroud system . It's on a tubular stand so a shroud may be to heavy on one side . I think I'd have to make a mobile stand to do it right . Sheesh , yet another project


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## DaninVan (Jan 1, 2012)

Oh fer goodness sakes, Rick! you don't have to make anything; the 'funnel' is widely available off the shelf.
https://www.kmstools.com/magnum-b-gulp-dust-hood-6606


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## DaninVan (Jan 1, 2012)

More stuff...
https://www.kmstools.com/woodworking-23000000/dust-collectors-23030000/hose-and-fittings-23030300/


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## RainMan 2.0 (May 6, 2014)

DaninVan said:


> Oh fer goodness sakes, Rick! you don't have to make anything; the 'funnel' is widely available off the shelf.
> https://www.kmstools.com/magnum-b-gulp-dust-hood-6606


Dan that's to funny as I have that very funnel in my basement somewhere . I was going to try attaching it to my miter saw someday but I didn't think it was big enough .
I'd like to make it so it moves when you turn the saw for a 45 degree cut . I'm sure I can put some metal brackets on the saw somewhere .


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## DaninVan (Jan 1, 2012)

! Aye caramba! A cardboard box with a 4" hose out the bottom will do the job, not perfectly mind you, but light years better than nothing'
_'Better to light one candle than to curse the darkness' _or somethin' like that...


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## ScottyDBQ (Jul 5, 2008)

I used plastic pipe and ran copper ground wire inside it, but went outside the pipe to go around gates or when splicing into another line going off a "y"


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## sunnybob (Apr 3, 2015)

RainMan1 said:


> Yes it's a makita and I was thinking the same thing , remove the bag and put a hose onto its outlet . That would get a lot I suspect . A shroud would get more maybe yet? I'll have to fo a test and see if I cam justify a shroud system . It's on a tubular stand so a shroud may be to heavy on one side . I think I'd have to make a mobile stand to do it right . Sheesh , yet another project


Heres a pic of my mitre saw attached to the ducting.

It catches a great deal of the dust, very pleased with it. Normally theres a top guard over the blade, but I removed it for a particularly awkward cut so I could see where the blade was going. I was shocked by the amount of dust off the top of the blade, even with the extraction running. I only cut about 4 ft of wood, but I was covered head to toe in dust. Good job I had my mask on (g)


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## Daikusan (Apr 12, 2013)

Daikusan said:


> Since I am a detail nut, I ended up at Bill Pentz website Dust Collection Research - Home I found his information technical and detailed. His overview is great. The other pages are deep and technical. They provide ideas many woodworkers do not consider. He also provides detailed plans for building your own DC system. *AND *he does discuss static.


In the edit to my pervious post - the links for static were not saved for what ever reason. Dust Collection Research - Ducting 
and DC Myths on PVC PVC

The second link is quite detailed with documentation – thought provoking. I wonder what our experts here have to say with his arguments.


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## Cherryville Chuck (Sep 28, 2010)

Steve he basically says that the chance of static causing a fire in a home collection system is unlikely, it's not impossible. Getting a shock is a strong possibility though and other members have documented this. Over time there have been numerous explosions in flour mills, grain elevators, coal storage facilities, sawmills, etc. While static discharge may not be the proven source of ignition in any of them, it is high on the possibility list. 

I personally live many kilometers from a fire department so I can't afford to take risks. Anything that reduces risk I do. As I said about grounding my DC, it only took about an extra hour and I had wire laying around so there was no extra cost. The effort I put in to reduce my risk was so minimal that it wasn't even a consideration.

BTW, he also mentioned two instances where mechanical sparks (metal to metal contact) caused fires. Anytime I've been using my machinery I go back into the shop several hours later and do a "sniff test" just to make sure and sometimes I'll walk over to the DC bag and see if I feel heat.


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## sunnybob (Apr 3, 2015)

I read quite a lot of those technical items posted, and the only one that had really serious static (1 1/2" sparks and leaving burn marks) was not only pvc pipe, they were cutting plastic! plastic shreds rubbing inside a plastic pipe for what, 10 hours shifts? maybe 24 hour shifts? Understandable problems there.

My last 6 years of work was on military bases, and any work involving heat of any kind required a "hot work permit" All work had to finish 3 hours BEFORE knocking off time, in order to do a fire sweep before actually leaving.


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## Stick486 (Jan 4, 2013)

Steve he basically says that the chance of static causing a fire in a home collection system is unlikely, it's not impossible. 
*static discharge in a VOC environment wasn't mentioned.. how many here have became ''light headed'' working in their self induced VOC atmosphere and chose to ignore/take the hint...
damage to mechanical/electronic personal medical support equipment that could really screw w/ your day.....

VOC environment; (as in fumes from)...
contact cement..
FRP/construction adhesives...
thinners...
cleaning agents...
oil based spray paint/shellac/lacquer... (rattle can)...
primers/sealers... 
the list goes on and wood dust fines takes a back seat.... *

Getting a shock is a strong possibility though and other members have documented this. Over time there have been numerous explosions in flour mills, grain elevators, coal storage facilities, sawmills, etc. While static discharge may not be the proven source of ignition in any of them, it is high on the possibility list.
*I believe we are seeing ''It can't/won't happen to me'' mind set... 
the moment ''what if'' and ''the possibility'' comes to mind play it smart -CYA... *

I personally live many kilometers from a fire department so I can't afford to take risks. Anything that reduces risk I do. As I said about grounding my DC, it only took about an extra hour and I had wire laying around so there was no extra cost. The effort I put in to reduce my risk was so minimal that it wasn't even a consideration.
*why is it some can't see the forest for the trees???... [(An expression used of someone who is too involved in the details of a problem to look at the situation as a whole)...

BTW, he also mentioned two instances where mechanical sparks (metal to metal contact) caused fires. Anytime I've been using my machinery I go back into the shop several hours later and do a "sniff test" just to make sure and sometimes I'll walk over to the DC bag and see if I feel heat.
smart...*


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## schnewj (Nov 18, 2013)

I think that we all agree, that, grounding of the duct is a reasonable (smart) thing to do. It never hurts to be proactive in anything no matter how possible or probable. However, I'll reiterate my position. The possibilities of a fire or explosion in a small shop environment is low, not impossible but LOW. The chance of fire or explosion in a commercial environment is greater due to the nature and duration of the work. 

I think that there is enough published date to support the above.

In a small shop environment, I would be more worried about static shock. As Stick has pointed out, it can effect sensitive things like; pacemakers, hearing aids, etc. Just as much of a concern is the surprise of a static shock and how people can and will react. I certainly wouldn't want to jump and come in contact with a moving, whirly thing. Would you?

Grounding of ducts is pretty basic and I have to ask, why would you not do it?

Bill


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## Daikusan (Apr 12, 2013)

Cherryville Chuck said:


> Steve he basically says that the chance of static causing a fire in a home collection system is unlikely, it's not impossible. Getting a shock is a strong possibility though and other members have documented this. Over time there have been numerous explosions in flour mills, grain elevators, coal storage facilities, sawmills, etc. While static discharge may not be the proven source of ignition in any of them, it is high on the possibility list.


Chuck, I totally agree. I am a proponent of eliminating any type of static discharge. Static discharge is a very destructive event. Few people understand the dangers of ESD. The cause of gas station fires is another area in which people tend to ignore static. Use of cell phones while fueling is a whole different issue.

In fact, ESD may be the culprit of the tragic fire in Taipei two days ago. Even though static is not mentioned as a possible source of the spark in the article, it is quite possible it was the source. The article and video clearly demonstrate the dangers of a spark and a volatile atmosphere. The dust - likely corn starch. 

Powder explosion may have caused Taiwan fire - News - NHK WORLD - English


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## Stick486 (Jan 4, 2013)

I wonder id ESD has taken out speed controllers, electronic switches and soft starts on tools...


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## eccentrictinkerer (Dec 24, 2007)

FWIW, I spent 5 years selling fire, spark and explosion suppression systems used in food handling systems, industrial dust collection systems and computer room systems.

Sparks generated by home dust collection systems are not generally going cause fires. In fact, no one I know has ever found a single instance of static sparks causing a fire or explosion in a home system. You may injure yourself and crack your elbow if you jump back from a spark. ;-)

I use a single strip of aluminum duct tape along the entire length of my 4" PVC ducting. I ground it to an AC outlet outlet ground. I do this to help minimize nuisance static buildup. It still happens, but I don't worry about it.

The following link has a ton of info on the subject:

https://home.comcast.net/~rodec/woodworking/articles/DC_myths.html


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## RainMan 2.0 (May 6, 2014)

eccentrictinkerer said:


> I use a single strip of aluminum duct tape along the entire length of my 4" PVC ducting. I ground it to an AC outlet outlet ground. I do this to help minimize nuisance static buildup. It still happens, but I don't worry about it.
> 
> The following link has a ton of info on the subject:
> 
> https://home.comcast.net/~rodec/woodworking/articles/DC_myths.html


J.D I'm liking your aluminum tape idea and will use it when the time comes


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## Daikusan (Apr 12, 2013)

Stick486 said:


> I wonder id ESD has taken out speed controllers, electronic switches and soft starts on tools...


Very likely a good percentage of them. Ever see the ESD video narrated bay a man that looks like Mr. Clean? 

According to him, NASA discovered the ESD problem through buying precision resistors from a manufacture in Calif. The resistors were 0.1% tolerance. When they arrived at NASA they were not the resistance they ordered. The Company bagged up a second set, yes you guessed it, in a plastic bag and overnighted them. Again when they arrived at NASA they were out of tolerance. The president of the company personally checked the resistors, bagged them, again in a plastic bag, and hand carried them to NASA. Yep, they were out of tolerance when they got there. They figured out it was low humidity in the airplane and ESD from the plastic that nailed them.

Wonder how well CNC machines are made to resist ESD. That could account for some of the erratic movements


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## Mike (Nov 22, 2004)

Using a separator to remove most of the dust from your vacuum or collector is a smart idea. This extends the filter life and is usually much easier to empty. Using filter bags inside a vacuum further reduces the fines that get to the motor and into the air. We tested the Dust Deputy Deluxe, the CV06 Mini and the Dust-right and found them all to do a good job.

The D3 and the CV06 mini come with kits for attaching them to the side of a shop vac. (The D3 also includes castors) Floor space is always at a premium so here is my solution: mounting the CV06 mini to a Bosch L-Rack-S so it will lock onto the top of my VAC140A. Two holes, two 1/4-20 x 1" carriage bolts, washers and nylock nuts is all it takes.


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## subtleaccents (Nov 5, 2011)

DaninVan said:


> JT; I'd be very surprised if putting the Copper ground wire on the _outside_ of the PVC piping would be effective. My understanding was that it needed to be on the interior where of course it brings up other problems.


Just got back to this thread. 

That is why I stated to run the wire inside the pipe. I don't consider running it on the outside to be effective at all. I am not worried about chunks of debris getting caught on wire. Even on the metal systems I used, I made particle separators at each station that collected the chunks so they wouldn't make it to the collector.
Sounds like no one uses the metal ducting. I found it lighter to support, easy to make alterations and cheaper to use.


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## Stick486 (Jan 4, 2013)

subtleaccents said:


> Sounds like no one uses the metal ducting. I found it lighter to support, easy to make alterations and cheaper to use.


you can't be serious...


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## Harol (Apr 15, 2015)

I totally agree a friend of mine actually set his motor on fire from a static charge igniting the dust in an enclosure where the collector was Lucky for him the only damage was to the motor


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## schnewj (Nov 18, 2013)

Harol said:


> I totally agree a friend of mine actually set his motor on fire from a static charge igniting the dust in an enclosure where the collector was Lucky for him the only damage was to the motor


Are you sure it was a static discharge, or did the motor short and burn up? 

There has never been a documented case of this happening without tons of fine dust in the air. It would be something I would expect in a commercial setting or a grain silo, not a hobby type shop!

Bill


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## woodywoody (Feb 19, 2010)

I have not seen the old wives tale of static causing dust collection fires in years. This has been disproven many times. If it were true, then we would be reading about all these fires each week. Must be an old article.


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## DaninVan (Jan 1, 2012)

My dust collector has a grounded plug; how on Earth (heh...pun definitely intended) could static build up on the motor? Or the DC for that matter?


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## kermitp (Jun 30, 2011)

We have 2 dust collection systems that are located outside our woodshop. Both are 4 inch PVC pipes with several dust ports along the walls. Never have had any problem with static build up. 
I was wondering if your term plastic include PVC pping? 

We, also, have 4 standalone shop vacs connected to power tools not located close to the external vaccum systems.
Even with all of this we still have a considerable amount of sawdust that does not get sucked out with outr vaccum systems. 

WE tried the Cyclone system but it flat did not work proprerly. It is okay on smaller power tools but not Planner, table saw, and router table setups. Just to much volume.


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## RainMan 2.0 (May 6, 2014)

kermitp said:


> We have 2 dust collection systems that are located outside our woodshop. Both are 4 inch PVC pipes with several dust ports along the walls. Never have had any problem with static build up.
> I was wondering if your term plastic include PVC pping?
> 
> We, also, have 4 standalone shop vacs connected to power tools not located close to the external vaccum systems.
> ...


Kermit I'm liking the idea of having the DC mounted outside , wish I had that option.

One thing I'm finding is if I could do it all over again I'd go to a more powerful DC then I have now , preferably something that has enough suction to throw small planes off course if they got to close to the neighbourhood


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## Herb Stoops (Aug 28, 2012)

How about Drones checking you out?

Herb


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## RainMan 2.0 (May 6, 2014)

Herb Stoops said:


> How about Drones checking you out?
> 
> Herb


lol I almost changed it to drones ,but I'm such a boring person I doubt they'd be to interested in me . My cat actually left me and I was told they were low maintenance


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## Lkessler3 (Jun 8, 2010)

Interesting discussion regarding static and potential issues associated with such.
However, given that a lot of us hobbyists have small shops and have no ability to create a system which is permanently ducted with a stationary DC the relevance is minimal.

If we move on to another thread here and solicit insight from more experienced and informed readers on issues many hobbyists face like: how to accomplish dust collection on a small shop where all of the tools (or the vast majority of tools) are rolled into and out of position to be used it would be very helpful.


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## Herb Stoops (Aug 28, 2012)

Lkessler3 said:


> Interesting discussion regarding static and potential issues associated with such.
> However, given that a lot of us hobbyists have small shops and have no ability to create a system which is permanently ducted with a stationary DC the relevance is minimal.
> 
> If we move on to another thread here and solicit insight from more experienced and informed readers on issues many hobbyists face like: how to accomplish dust collection on a small shop where all of the tools (or the vast majority of tools) are rolled into and out of position to be used it would be very helpful.


Skip we have such a Thread going right now that has a lot of good stuff in it
http://www.routerforums.com/project-plans-how/70874-group-cyclone-dust-collector-build.html

Herb


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## RainMan 2.0 (May 6, 2014)

Welcome to the forum Skip


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## Professorss (Sep 7, 2012)

The legend lives on! You do not have to ground a dust collection system. Fine woodworking ran engineering tests and published results a few years ago. With metal ductwork there should be no question about grounding whether you believe the stories or The result is severe clogging. If still not convinced, answer this question: shopVacs have plastic ductwork (hoes) and dust receivers. No one is advising that they be grounded.not. FWW TESTED PLASTIC AND IT WAS NO PROBLEM. NOW IF YOU DECIDE TO PLAY IT SAFE, THEN AT LEAST DO IT CORRECTLY. THE STATIC CHARGE BUILDS UP ON THE INSIDE OF THE PLASTIC DUCTWORK, SO THE COPPER WIRE DISCHARGE PATH MUST BE EESTABLISHED IN SIDE THE DUCTWORK. NO MATTER HOW MANY TURNS YOU WRAP ON THE OUTSIDE, NO BENEFIT WILL BE RECEIVED. 

The validity of this analysis is upheld by the Adsense of reports of home workshop explosions. It is within the realm of possibility that explosions occur on industrial installations. ,Air velocities are much greater and the static charge buildup would be greater. 

There is one major negative with the grounding system, if you decide to install it. The internal wires have to be flat against the ductwork or else they will trap dust and chips


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## WayTooLate (Jul 4, 2012)

Professorss is right - exploding dust collectors from static sparks this is a 'legend'. Many testing labs and government agencies have desperately tried to replicate this, with NO success. Apparently, the air flow is too rapid to permit the heat build-up for the wood to combust. Yet, the wreckage of a dust explosion is so catastrophic that it requires substantial 'due diligence' to prevent this as a possible source. So the ill-founded fear of an unproven possibility keeps the legend alive. 

I have had the three experiences of "dust fires". Where sparks from hitting screws and nails generated sparks that began a fire. Once, in the belt sander itself. Once in the DC's dust bin and once in the DC's filter bag. These were NOT explosions. These were smoldering embers that took 15-45 minutes to grow to the point where the smell of something burning was detected and started looking for the source. 

If the saws and sanders are grounded and the DC is grounded, then I would not sweat the duct work. ... IF I was going to put ground wires on plastic ducting, I would place them on the outside. Not to dissipate the static charge, but to shorten the 'shock path'. It the shock occurs from my fingertip and my palm is grounded, my muscular twitch is smaller than if I allow my arm muscles to experience the jolt. The pain and surprise is still there - but my bodily reaction is less likely to resemble a fish in the bottom of my boat! 

But as this thread stated at the beginning, wood dust is harmful to our lungs. Getting it out of the air is the most important thing. In browsing through the thread, I may have missed anyone else suggesting my 'Poor Man's Purifier". I use a cheap 20" square box fan (~$18 at Wal-Mart) and tape a 20x20" furnace air filter to the 'blow' side of the fan. While I cannot remove ALL the dust in the air in my shop, I use that fan behind me to blow clean air where I am breathing. The may be dust settling in other parts of my shop - but my source of clean air keeps it from settling in MY lungs. 

Hope this Helps!
- WayTooLate


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## RainMan 2.0 (May 6, 2014)

Guys don't they claim that the hoses are anti static . I know Festool does . Have no idea if there's any merit to calling there hoses anti static , maybe just a ploy to charge 10 bucks a foot .
I know when I was at WP they said the 4" I was buying was considered anti static too , but recommended a ground wire to avoid getting a shock lol


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## Herb Stoops (Aug 28, 2012)

RainMan1 said:


> Guys don't they claim that the hoses are anti static . I know Festool does . Have no idea if there's any merit to calling there hoses anti static , maybe just a ploy to charge 10 bucks a foot .
> I know when I was at WP they said the 4" I was buying was considered anti static too , but recommended a ground wire to avoid getting a shock lol


How much a foot for the ground wire and conectors?
Herb


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## Al_Breit (Jul 27, 2014)

*Ducting for dust collection*

In an article from Wood Mag the went into detail as how to use PVC for duct work and they wrapped the outside of the PVC with copper wire and ran it to a ground. I had previously heard that it should be run on the inside of the PVC. Just want o be safe and no fire hazard. This page will not let me post the link here.


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## RainMan 2.0 (May 6, 2014)

Al_Breit said:


> In an article from Wood Mag the went into detail as how to use PVC for duct work and they wrapped the outside of the PVC with copper wire and ran it to a ground. I had previously heard that it should be run on the inside of the PVC. Just want o be safe and no fire hazard. This page will not let me post the link here.


Welcome to the forum Al . I can post it for you if you pm me with the link


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## DaninVan (Jan 1, 2012)

One of the other members just recently posted a comment to the effect the running it on the exterior does absolutely nothing. Just sayin...


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## Herb Stoops (Aug 28, 2012)

And the beat goes on................

Herb


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## Stick486 (Jan 4, 2013)

DaninVan said:


> One of the other members just recently posted a comment to the effect the running it on the exterior does absolutely nothing. Just sayin...


metal is so much cheaper...


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## old55 (Aug 11, 2013)

Welcome to the forum Skip.


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## old55 (Aug 11, 2013)

RainMan1 said:


> My cat actually left me and I was told they were low maintenance


But you still gotta feed 'em Rick.>>


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## old55 (Aug 11, 2013)

Welcome to the forum Al.


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## vindaloo (May 30, 2009)

Router Forums said:


> ........ Keep in mind that wood dust ignites easily........


Apparently this was dust related. They make wood flour and turn it into cat litter.

Bosley explosion: Four missing in Wood Flour Mills blast 17/7/2015


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## RainMan 2.0 (May 6, 2014)

Guys I'd be interested in hearing about how you dealt with an automated switching system in order to have your table saws , sanding machines etc make your DC come on automatically when they power up . 
My router is Festool so I bought there DC so that's taken care of , but my TS is driving me crazy . My TS and most of my other equipment is 240V except for my miter saw. The General DC is 120V . 
So I searched and found this interesting setup from LV 

iVac Pro Dust Collection Control System - Lee Valley Tools


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## RainMan 2.0 (May 6, 2014)

Gee if your rich I see they even make automated blast gates too . Go figure

http://www.leevalley.com/en/wood/page.aspx?p=71030&cat=1,42401,72660&ap=1


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## boogalee (Nov 24, 2010)

So for $700.00 I would not have to walk 30' to open a blast gate. I like it but not for that kind of money. I do have the lone ranger remote to turn on dust collection.


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## RainMan 2.0 (May 6, 2014)

boogalee said:


> So for $700.00 I would not have to walk 30' to open a blast gate. I like it but not for that kind of money. I do have the lone ranger remote to turn on dust collection.


Well I do need the exercise


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## RainMan 2.0 (May 6, 2014)

RainMan1 said:


> Guys I'd be interested in hearing about how you dealt with an automated switching system in order to have your table saws , sanding machines etc make your DC come on automatically when they power up .
> My router is Festool so I bought there DC so that's taken care of , but my TS is driving me crazy . My TS and most of my other equipment is 240V except for my miter saw. The General DC is 120V .
> So I searched and found this interesting setup from LV
> 
> iVac Pro Dust Collection Control System - Lee Valley Tools


Well I just ordered one 115V receiver and 3 transmitters . Sure looking forward to installing these .
Hope they work as advertised :|


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## WayTooLate (Jul 4, 2012)

*Remote Swiching DC's*

Remote switching is getting a bit far off topic for this thread, but I purchased a *NK Technologies* 'AS1 Current Switch' from Trask Instrumentation. We have a commercial shop with 4 shapers, TS, RAS, Double MiterSaw, Pegger and Single End Tenoner that is all served by one large DC. Whenever anyone switches on any one of these items, it triggers the DC automatically. Doorbell wire from the Switch to the DC relay and we eliminated anyone from saying, "It's only 3-4 cuts, it won't be a mess..." 
The best part is the switch was only $65.00. You can use it so anytime one item is started, it will trigger something else. 

Hope this helps!


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## RainMan 2.0 (May 6, 2014)

Hey all , I was wondering if you can use 4" ABS for a dust collection system . Like does the 4" flexible hoses and blast gates interface to 4" abs or do they intentionally make it so that you have to use there product ?


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## WayTooLate (Jul 4, 2012)

Rick - 
4" ABS will work for ducting. The flex hose is what gets tricky, 4" Hose isn't always/exactly 4". Different styles/types/mfgrs all vary slightly. You may have to experiment with some fittings to see if your flex hose slips over straight pipe or fitting's OD. Sometimes you find an odd 'adapter fitting' with an OD that fits the hose - put one of those on the machine end of each run... 

I would strongly recommend using (2) 45's instead of (1) 90 for corners. Put 4" of straight pipe between the 45's and it will dramatically reduce your suction losses. If you can find large 'sweep' elbows, they are the best. Electrical conduit uses these, but 4" electrical fittings are not as inexpensive...

Hope this helps!
Jim


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## RainMan 2.0 (May 6, 2014)

WayTooLate said:


> Rick -
> 4" ABS will work for ducting. The flex hose is what gets tricky, 4" Hose isn't always/exactly 4". Different styles/types/mfgrs all vary slightly. You may have to experiment with some fittings to see if your flex hose slips over straight pipe or fitting's OD. Sometimes you find an odd 'adapter fitting' with an OD that fits the hose - put one of those on the machine end of each run...
> 
> I would strongly recommend using (2) 45's instead of (1) 90 for corners. Put 4" of straight pipe between the 45's and it will dramatically reduce your suction losses. If you can find large 'sweep' elbows, they are the best. Electrical conduit uses these, but 4" electrical fittings are not as inexpensive...
> ...



Thanks Jim the concept using 45's is good to know . A guy at work suggested PVC as it looks better as its normally white . 
Color doesn't really concern me as long as it's not pink


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## RainMan 2.0 (May 6, 2014)

Guys I need to put a 4" pipe in the middle of my garage to my table saw , so instead of tripping over it on the floor I was going to surface mount it to the ceiling . But I have to make some funky turns to get past the garage door opener .
So my other thought is to go directly from the DC and up the wall into the attic of the garage and secure it above the joists , then pop out over the right hand side of the TS . This way it would be hidden . I want to run an outlet above the TS to so its no big deal , just wondering if condensation is going to be an issue . I think covering the abs pipe with insulation should help with any moisture issues


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## Al_Breit (Jul 27, 2014)

Who is Dr. Rod Cole on grounding PVC, never heard of him!


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## RainMan 2.0 (May 6, 2014)

Hey guys speaking of dust extraction , I can get this boom that extracts the dust over the table saws blade used for 100 bucks . It's a beast and I'm not sure if I really like it as the hood that's over the blade is its kinda huge and looks as though it would obstruct your view to much .
Any opinions on this as I was hoping someone has used this before .

I'm really thinking about buying it and tossing the hood and making my own from 1/2" lexan that I have lying around . Having the boom system would certainly give me a head start though instead of starting from scratch .

#50-EXBC/50-EXBC-CM10/50-EXBC-CM14 ? 10? overarm blade cover system with dust collection capability


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## Admin (Feb 13, 2012)

RainMan1 said:


> Hey guys speaking of dust extraction , I can get this boom that extracts the dust over the table saws blade used for 100 bucks . It's a beast and I'm not sure if I really like it as the hood that's over the blade is its kinda huge and looks as though it would obstruct your view to much .
> Any opinions on this as I was hoping someone has used this before .
> 
> I'm really thinking about buying it and tossing the hood and making my own from 1/2" lexan that I have lying around . Having the boom system would certainly give me a head start though instead of starting from scratch .
> ...


Did ya do it? >


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## RainMan 2.0 (May 6, 2014)

Cricket said:


> Did ya do it? >


No but I'm still debating . Could be to late , not sure .
I'm thinking of doing it from scratch and going with 2" abs , so the bottom of the TS would be a 4" inlet and the blade a 2" . Tough call


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## schnewj (Nov 18, 2013)

RainMan1 said:


> No but I'm still debating . Could be to late , not sure .
> I'm thinking of doing it from scratch and going with 2" abs , so the bottom of the TS would be a 4" inlet and the blade a 2" . Tough call


What's your time worth? Spend a $100 and just install it or spend several hours fabbing and fitting! Sometimes a short cut is not the fastest way to get from A to B.


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## RainMan 2.0 (May 6, 2014)

schnewj said:


> What's your time worth? Spend a $100 and just install it or spend several hours fabbing and fitting! Sometimes a short cut is not the fastest way to get from A to B.


You make a ver good point Bill . My issue is I'm wondering if it's going to be a bother having that thing hanging over the blade . Tough call , but I have to say a lot of dust is created on top of the table and it would be nice to lesson it


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## DaninVan (Jan 1, 2012)

Why ABS instead of PVC? The ABS is way heavier and more expensive, and so are the fittings. 
I will concede that the ABS isn't as fragile, but were you planning on hitting it with a hammer?
Ipex | ABS PIPE 4 inches x 12 ft CELL CORE | Home Depot Canada
Ipex | PVC 4 inches x 10 ft SOLID SEWER PIPE | Home Depot Canada


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## RainMan 2.0 (May 6, 2014)

DaninVan said:


> Why ABS instead of PVC? The ABS is way heavier and more expensive, and so are the fittings.
> I will concede that the ABS isn't as fragile, but were you planning on hitting it with a hammer?
> Ipex | ABS PIPE 4 inches x 12 ft CELL CORE | Home Depot Canada
> Ipex | PVC 4 inches x 10 ft SOLID SEWER PIPE | Home Depot Canada


I'm all for PVC too.

I'd like to actually come off the ceiling with a flexible hose and build a hood that attaches to my riving knife . Not sure if it's doable or not , and it wouldn't work when using the dado blade


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## Yukoneric (Mar 6, 2012)

This is based on the Thein dust collector. Not counting the vacuum I have maybe $50 invested. There is a hog wire form to hold the garbage bag in place.


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## paul tomlinson (Jun 27, 2010)

WayTooLate - 'Poor Man's Purifier". I use a cheap 20" square box fan (~$18 at Wal-Mart) and tape a 20x20" furnace air filter to the 'blow' side of the fan.

Good idea excepting using the 'blow' side for the filter, I was always told that standing waves are formed in front of a fan when the flow is obstructed. The 'suck' side does not suffer from this problem. In my experience this is the case.


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## coxhaus (Jul 18, 2011)

I have 2 forums of dust collection. I have a small shop with 1 man use and did not want piping all overhead. I bought a used Rikon 12 gallon dust collector. It is metal and has a grounded plug. I move it from tool to tool using a 10 foot hose. It seems to fill with dust so I assume it is working. I have never used anything else. My shop is very small scale.

For hand tools like the Bosch 3725 sander I use a Fein Turbo I shop vac. This seems to work pretty well for hand sanding. I see almost no dust even if I sand sheet rock. This is a very light weight shop vac which is easy to move and carry. Even my wife likes it to clean the inside of her car. It is easy for her to carry. I took the wheels off which reduced the weight even more. The other thing I like about the Turbo I vac is I can plug my hand tool into the shop vac and both the vac and tool will turn on at the same time.


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## Stick486 (Jan 4, 2013)

@jah3-maniac...

welcome Paul...
8 years a member and nary a peep...
that has to be some kind of record..


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## DesertRatTom (Jul 3, 2012)

TheCableGuy said:


> Yes it's a makita and I was thinking the same thing , remove the bag and put a hose onto its outlet . That would get a lot I suspect . A shroud would get more maybe yet? I'll have to fo a test and see if I cam justify a shroud system . It's on a tubular stand so a shroud may be to heavy on one side . I think I'd have to make a mobile stand to do it right . Sheesh , yet another project


I used a shower curtain as a shroud around my sliding miter. The picture shows it simply draped down, but I now have the tail folded into a collection box with a DC port on the bottom. Tap the curtain sides once in awhile to clear it up. This really works very well. The Bosch saw has a port, but it is not great. 

I also use Rockler's metal coil, plastic expandable 4 inch tubing, which gets shifted from tool to tool. Arranged the shop so this only has to reach 8 feet max to attach to every dust making tool.

I prefer to sand outside, but I have a 35mm Bosch expandable hose with a 4 inch adapter on one end that slips into the main DC hose so I can clean out the table saw, or even plug into a portable too. In a pinch, I can also use a big shop vac.

The dust goes through a 30 gallon separater, then through a 1hp blower, then outside through a 20x30 inch box with a big washable filter on the front. I clean it out from time to time and it is amazing how fine the dust in there is. I used to have a bag, but it was a very bad fine dust maker. Middle picture is the DC system, separator, hose and blower. The hose stores opening up so I can just plug in the 35 mm hose.


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## Professorss (Sep 7, 2012)

Most of what you wrote is correct, more or less. You did make serious errors With respect to static charges. there is a lot of debate about the danger that it poses. It is insignificant for small shops with the typical machine designed for hobbyists. The air velocity is not great enough to build the static charge dangerous levels. For an understandable discussion check out the Fine Woodworking archive. There is nothing wrong with grounding your system if it is done properly. If you do it as you described, using non-conductive material like ABS or plastic drains, and then grounding it externally, you have done two things wrong. (1) Non-conductive materials allow the charge to build up inside the pipe, not outside (after all it is non-conductive. Metal ducting will not permit building up a charge, inside or outside, provided you bridge any gaps in conductivity introduced by non-conductive so fittings. Let's say you have already installed or intend to install non conductive ductwork. To be very cautious, you should ground the system. But here is the rub: the bare copper . ground wire must be installed INSIDE the ductwork. That is because the plastic prevents any charge that builds up inside the ducts to be conducted to the outside. Is that a problem? Almost always. Unless you can keep the wire flat against the ductwork, the gap may be too large to allow the charge to jump to the ground wire. It would then discharge into the fine dust and explode. There is actuall a more likely problem. Wires must be joined whenever the ductwork goes off in multiple directions, like at a tee or wye joint. This is a perfect trap for larger pieces of wood and dust. Before long you have a clog. If you need to clear the blockage, the joint and the wire junction would have to be disassembled, cleaned and reassembled. Best practices would have us use metal ductwork, but a short run of hose to connect to a machine can be grounded and would not pose a realistic risk.


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## WayTooLate (Jul 4, 2012)

To Desert Rat Tom: 
I like your set-up. Simple and effective. Do you have a baffle or something inside your drum? If not, I'd recommend a Dust Deputy on top of the drum or (preferably) a Thein Separator. They are home built devices and the work, GREAT! Google it for plans and forums. 

To Professorss: 
I think it is important to remember that the primary reason for eliminating static discharge is avoiding zapping our own fingers. Dust explosions are nasty events even in 'home garages'. However, there has NEVER been a documented case of a static-induced dust explosion. Testing labs around the world have spent millions of dollars trying to replicate one - unsuccessfully. 

Every dust explosion investigation has determined another form of ignition. In home incidents, the overwhelming cause is sanding or grinding sparks. (Hitting a nail or screw in your workpiece.) The psoark can smolder before hours before open flames develop. Introducing those embers to airborne dust can be catastrophic, but not from static. 

Firemen will tell you there are three things necessary for combustion: Fuel, Oxygen and Heat. In a DC, you have plenty of fuel and Oxygen, but a static spark isn't capable of generating the heat necessary for combustion. The zap can be painful to your finger, but it is pain from electrical stimulation, not heat. 

So I would encourage everyone to ground their systems. Do so to save yourself the annoying 'zap', but don't lose sleep over potential dust explosions. 

Hope this helps!


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## Professorss (Sep 7, 2012)

*Dust collector grounding*

Spent a good bit of time discussing this topic in a reply last week. Don't see it in the threads., yet I received an email telling me I a m part of the thread.

What happened?


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## kermitp (Jun 30, 2011)

professorss, your post of 2/29/16 is in the forum, at least in mine.


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## marvingreenberg (Jul 16, 2012)

I think someone should update the header to this thread. Recommending NON conductive duct work seems plain WRONG. 
From "Designing your dust collection system to meet NFPA standards (National Fire Prevention Assn)" 

Component materials must be conductive. Don't select duct made of plastic, which is nonconductive. If your ductwork includes flexible hose, the hose should be molded with grounding wires, and you must clamp these wires to the upstream and downstream metal ducts to ground the hose.
I used basic 6" galvanized ductwork for most of the parts of my system. It's not much different in price from PVC. 

I don't have "URL post" authority, but you can google that title....


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## Professorss (Sep 7, 2012)

Inside is not only most efficient, it is the only way! But it isn't necessary. Search for FineWoodworking article on the topic. Facts not rumors.


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## eccentrictinkerer (Dec 24, 2007)

marvingreenberg said:


> I think someone should update the header to this thread. Recommending NON conductive duct work seems plain WRONG.
> From "Designing your dust collection system to meet NFPA standards (National Fire Prevention Assn)"
> 
> Component materials must be conductive. Don't select duct made of plastic, which is nonconductive. If your ductwork includes flexible hose, the hose should be molded with grounding wires, and you must clamp these wires to the upstream and downstream metal ducts to ground the hose.
> ...


Think of the ten's of thousands of home dust collection systems that have been built using PVC and other non-conductive piping.

The biggest danger of static build-up is a shock that causes you to smack your elbow into your drill press column.:smile:

As has been stated here there have been no documented fires/explosions in home shops due to static build up.

I spent many years selling and designing fire protection systems for computer rooms, coal handling systems, industrial sawdust collection systems and food dust systems (think oily cheese dust for Cheeto's. Highly explosive!). These all were systems where fires/explosions were a concern. Home shop dust handling systems.. nope.

Just sayin'. 0


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## katabrontes (Nov 12, 2014)

I cannot agree with the advice about static. Non conducting pipework is the cause not the cure. It is the friction of the air and dust along the pipework that creates the static. Metal pipework if earthed will eliminate it just as it does with a coffee grinder if the spout is either metal or lined with aluminium foil and grounded to the metal case of the grinder. Wrapping a copper wire round a non conducting pipe will achieve nothing unless it is inside the pipe and in contact with the dust when it will help a little.


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## DesertRatTom (Jul 3, 2012)

update: The DC setup I showed in this thread has been retired and replaced by a 2hp Harbor Freight DC unit. I still use the chip collection drum. On sale, and with a 25% discount coupon the HF was $187, plus $140 for a drum filter for the shop unit. Far more effective than what I showed in the post on this thread. Should still put in the Thein separator, but haven't gotten around to it. The old setup was not bad, but not nearly as effective as the HF unit. 

You can replace the HF impeller with a larger metal one from Rikon but you don't want to let chips hit it--so a chip separator is required. BTW, the chip collector will hold most of the sawdust, so you must empty it regularly. I have a 30 gallon fiber drum for this purpose, and try to empty it when it gets half full. If you are doing a lot of production, you'll probably need a larger drum. 

And I would then consider drilling a large hole and cementing a glass panel under the hole so you can check dust levels. If you build a Thein separator, you'll need to work out a way to check the sawdust level. One method is to drill a half inch hole through the top and Thein, and place a dowel through it. Put a small "foot" on the rod. Place a mark on the dowel to indicate the empty level, then pull it up and mark the full level in red. Makes checking depth of sawdust quick and easy--pull up, drop down to the top of the sawdust and you know. You get a reduction in suction if it gets too full. 

I have a small shop, so the drum filter is a must. it filters down to 1 micron and the relatively clean air returns to the shop so I don't lose heat in winter or AC during summer.

One other thing, the shower curtain works extremely well on the sliding miter saw. But you can increase its effectiveness by pulling the blade forward to make a shallow cut first, then push back to cut through the rest. The first pass makes a channel so FAR MORE sawdust shoots back into the curtain. The other change is instead of having sawdust drop down into a box, the curtain is drawn down and taped to a 4 inch fitting, attached to a hose with leads back to a fitting where my main DC hose quickly attaches. My shop is too small for permanent piping and tools are arranged so about 12 feet of hose reaches every tool. There is also a smaller hose over the workbench that can drop directly into the main DC hose. 

The system is simple and in the end, cost no more than all the stuff I've purchased to try to cobble together a system that didn't hold a candle to the HF unit. I also installed a WEN brand air cleaner, about $130 from Amazon, which has a timer and speed control. I leave it running for a couple of hours after making cuts to thoroughlyfilter all the shop air. It has made it really nice to work in the shop. But I still wear a surgical style face mask at the least when I work in there, and a fan driven filter mask while making cuts. I like my lungs.

Hope this helps someone make a good choice on dust collection.


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