# Down draft sanding table



## Glenmore (Sep 10, 2004)

I could not believe the prices on these. I started building my own yesterday and went on line last night for some ideas.  And found some places are asking over a 100.00 and more for a simple project. I'm building mine out of 1x6 pine used some 1/4 ply with just drilling holes in it randomly. I intend to build mine 32" L x 24" W that should take a lot of sanding dust into the vacuum.


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## Daryl (Feb 11, 2005)

Are you going to post any pics as you build this.


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## NewMontanaWorkshop (Sep 10, 2004)

I have one that I built into the outfeed of one of my tablesaws. Simply a piece of 3/4" ply with holes drilled at 1-1/2" centers, then used the plunge router with a chamfer bit to soften the drilled holes.

It is currently hooked up to my HF dust collector, but I'm thinking I'll get better airflow if I pull the air cleaner down from the ceiling and mount the 'punched hole' top on that. The squirrel cage fan inside the air cleaner should pull more than enough air through the holes for effective dust containment.

Total cost...
$25 from a HVAC shop for a used furnace squirrel cage fan (4 speed).
$4 for some connectors and a bit of wire for the furnace fan.
Wood -- pretty much free, built from 'other peoples trash'.....


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## Jim-Iowa (Sep 3, 2005)

I too have one in the works. It won`t be pretty but should work fine.
I took a 24 X42" 1/4 pegboard panel. Drilled all holes out to 1/2". mounted it to 1x1 frame of pine.
second frame same material with metal lathe cover to hold filters.
The box 26X43 x30 on 5" casters is 7/16" OS board(Had it on hand) and am mounting a furnace fan for air flow.


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## Glenmore (Sep 10, 2004)

well I have it finished the only problem I've found with it is not enogh suction. Might have to go with the bigger hose. Unless maybe should I put a bottom onto it. It might have been a mistake to just set on the bench Stan and Jim-Iowa what do you think.  

Daryl I have the camera but not the time to figure it out. Can't get it from the mrs's she has her toys and I have mine and the camera is one of them.


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## NewMontanaWorkshop (Sep 10, 2004)

Going to be hard to get a shop-vac to pull enough volume I'm thinking.
Even my dust collector was not pulling enough to suck the dust off the table between the holes, although it did keep most of the airborn dust from leaving the top of the table.

The HVAC fan should pull enough air to do both -- along with filtering the air before recycling it back into the shop.

Hope that info helps.


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## Glenmore (Sep 10, 2004)

Stan I think your right I'll put my shop vac air purifier down on my work bench next time I'm sanding to see if that helps. Thanks


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## Jim-Iowa (Sep 3, 2005)

Glenmore said:


> Stan I think your right I'll put my shop vac air purifier down on my work bench next time I'm sanding to see if that helps. Thanks


If I`m getting this right, your using the 1 1/2" hose on your vacum ?
I would definately use the 2 1/2" if you have it.
And did you say you did not have a bottom on it?
Sealing the bottom would concentrate the suction to the box.
You did not mention how many holes and what size you used?
Since the vacum has good velocity but low volume, I really have no clue how many holes of what size it would handle. I know my Bt3100 , router table and CMS work pretty well with the 2 1/2 on my bigger vacum, the small one I have never hooked to a machine yet. I only use it to clean benches.

Don`t give up on this idea too soon, you may have to go back to the drawingboard a few times. But it is a worthy project to pursue. 
After gagging and coughing up MDf dust for a week, I`m regretting not getting my sanding table done more quickly.

I took the 1/4" pegboard holes out to 1/2" and countersunk them.
I may have to go to 3/4", some guys using the HVAC blowers report whistling with not enough or too small holes.


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## reible (Sep 10, 2004)

Hey it sounds like time for MATHMAN.

area of 2.5" circle is 4.9 sq. inches
25 1/2" holes is about the same area
a 1 foot by 1 foot piece of pegbd has 144 holes or about 9.5 times the area of the 2.5" hose attached to it. So if you make an air box that is 2 feet by 2 feet you have 38.4 times the area of the hose or like attaching a 12" hose to your shop vac. (holes have been increased to 1/2".)

BTW if you used the 1/8" holes you are at about a 3" hose area so the vaccume should be very close to what you get from the 2-1/2" hose. Has anyone tried that?

I've seen plans using a 30 gallon garbage can(metal) with hardware cloth (1/4" x 1/4" or 1/2" x 1/2") attached to a wood frame. That is then attached over the open can and a dust collector hose attached to a port high up on the can.

Ed


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## Jim-Iowa (Sep 3, 2005)

Reliable Thats good information! I tend to be more of hack and try type.
But we can all do with some math help.
They idea of using the standard size holes in the pegboard sounds great.


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## Glenmore (Sep 10, 2004)

Guys got my first shop notes today and they have one to build. I 'm going to cut down the sides from 6" to 1 1/2" and put a bottom on it so it will be less volume for the suction. Yes and I used a 1/2" bit for the holes. Thanks for the info guys. I'll try this and tell you how I make out.


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## Jim-Iowa (Sep 3, 2005)

Glenmore: If you have it you might want to tack in some flashing tin(or aluminum) on the corners.
I`m wondering if the 90 degree angles in a box would cause turbulence and leave dust in the corners? Just an inch up and an inch or two across the bottom and the sander vibration would cause the dust to move towards the center where the vacume could pick it up.
I think cutting the box down is a good idea, it will give the vacum less chance to lose velocity.


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## Glenmore (Sep 10, 2004)

Good idea I have some flashing thanks I'll line the bottom with that.


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