# concrete router table top



## gav (Oct 12, 2009)

Crazy idea or not ?
I've seen the threads on here where people have considered and even made granite tops for their router tables, and recently read this article about a home made tablesaw, and the guy makes a concrete top for it.
Fibre enforced concrete mixes are available pretty cheaply and it seem to me it would be easy to cast all holes and grooves in place.
Anyone heard of it being done, or have actually done it themselves ?
I'm sure it would cut down on vibration quite a bit and be quite flat and stable.

Just thinking out loud.


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## harrysin (Jan 15, 2007)

gav said:


> Crazy idea or not ?
> I've seen the threads on here where people have considered and even made granite tops for their router tables, and recently read this article about a home made tablesaw, and the guy makes a concrete top for it.
> Fibre enforced concrete mixes are available pretty cheaply and it seem to me it would be easy to cast all holes and grooves in place.
> Anyone heard of it being done, or have actually done it themselves ?
> ...


That much deep thinking Gavin can be dangerous. VIBRATION, if all is running correctly there shouldn't be any. Think about when you drop a cutter on the table and don't we all at sometime. Basic router tables have stood the test of time and although bells and whistles have been added over the years a strong bench with a tall adjustable fence is capable of superb work, in the right hands of course.

Now then, going back to my days in esoteric Hi-Fi, when Vinyl discs were the media, it was quite common to sit the expensive turntable on a Marble slab which in turn was sat on four squash balls, this gave perfect isolation from the outside world. You must realise that such audiophiles would invest between $1000.00 and $3000.00 on a turntable and another $500.00 to $1000.00 on a moving coil cartridge. Those were exciting days in my long career.


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## bobbotron (Jan 7, 2010)

Sounds like a neat idea! You could coat it in self leveling epoxy, or some other concrete sealant.


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## dutchman 46 (May 23, 2007)

Hello gav ! I read Harry's post, and I believe He said it all. If You drop a steel bit on concrete, You would have to sharpen it. Drop a carbide bit, and it's broken into pieces. Consider what carbide cost! and it's a no brainier, I would use wood ply or another flat substrate as osb, and such. Good luck on whatever You chose to do!


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## Phil P (Jul 25, 2010)

Hi Gav

Probably not so crazy, but quite probably a lot of work. I have to agree with Harry that if all is running well there shouldn't really be all that much vibration. It's often the lower speed stuff, like spindle moulders and table saws which have large diameter tooling which benefit from extra mass. 

I've made form work for fibre-strengthened concrete and I know that the fibre they use is UHMW-PE. I'm lucky enough to have several firms in this vicinity who machine this (one makes plastic hip joints) but the fibre is available from a limited number of builders merchants. How were you planning on flattening off the top? The concrete guys use a special angle grinder (called a floor grinder) but it doesn't finish off perfectly so the flooring contractor almost always seems to screed with a layer of lates before adding flooring carpet tiles, vinyl, etc. Latex wouldn't be suitable (too soft) for your purpose but I understand that those firms making concrete countertops add an epoxy admixture to the concrete and polish out with a wet random orbit (due to the extremely fine dust)

As for dropping carbide onto concrete, it's probably no worse than dropping it onto the cast iron table of a static machine such as an overhead pin router or the like. The sort of thing you do once and never repeat!

If you do go ahead I'd be interested in seeing how you get on as I'm really interested in the possibility of making my own concrete kitchen worktops.


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## Ralph Barker (Dec 15, 2008)

I'd suggest the new Swedish TempurConcrete - firm where you need it to be, but soft as a cloud when a bit goes to sleep on it.


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## bobj3 (Jan 17, 2006)

" Concrete " O No it must be a full moon again 

=====


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## downhill (Nov 21, 2008)

of course it would work fine... Worthless though if you ever have to move. I'm too old to move my LP and CD collection let alone a concrete slab..


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## gav (Oct 12, 2009)

Bob, no full moon tonight but I do kind of look like a wolfman at the moment.

So, apart from it being overkill and hard to move, so far the only downside seems to be the fact that bits could be damaged if dropped on it.
I wonder if 5 coats of polyurethane would soften that blow ?

Are bits damaged when dropped onto cast iron ?

I was considering upgrading my tablesaw top to concrete, like the link I posted, and just thought it could double as a router table.

I'm also considering making a bandsaw out of wood. Like the one here


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## bobj3 (Jan 17, 2006)

Hi Gav

Now I'm press Impress with home made band saw  but I don't think many could get it done, it's take very spec.person to do that build up..having plans it one thing but to get it right that's something else..
Band saws are cheap now days and have been around a long time, you can rework just about any of the band saw on the market and make them run very smooth and quite but after all it's just a band saw..not a steel mill..he said you can make it cheap, I don't think so, bicycle tubes are cheap but not the other parts that are needed..just the motor alone is 100.oo bucks....think down the road a little bit some day you may want to sale it and get a real one ,what do you think you can get for a home shop one..or to say what would you pay for home shop one.....

If you make one I would love your feed back on it  and picture of your bill fold after the build up..

I have dropped bits on a cast iron table and no damage now I have dropped them on the floor also and I have damage one or two in the many years I have used them..
I think it's how they hit..I did drop a solid carb.bit and it broke the bit into two parts and it was only a 3 ft.drop to the floor..some days you are lucky and some days your not..

"concrete /mable" for any table saw or router table your nuts, I see some table saws have them and they crack me up every time, once they crack or chip you have a real nice boot anchor ...and they will crack or chip over time unlike cast iron or Alum.tops.. 

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gav said:


> Bob, no full moon tonight but I do kind of look like a wolfman at the moment.
> 
> So, apart from it being overkill and hard to move, so far the only downside seems to be the fact that bits could be damaged if dropped on it.
> I wonder if 5 coats of polyurethane would soften that blow ?
> ...


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## sourdough (Jan 31, 2010)

*Harry HiFi*



harrysin said:


> That much deep thinking Gavin can be dangerous. VIBRATION, if all is running correctly there shouldn't be any. Think about when you drop a cutter on the table and don't we all at sometime. Basic router tables have stood the test of time and although bells and whistles have been added over the years a strong bench with a tall adjustable fence is capable of superb work, in the right hands of course.
> 
> Now then, going back to my days in esoteric Hi-Fi, when Vinyl discs were the media, it was quite common to sit the expensive turntable on a Marble slab which in turn was sat on four squash balls, this gave perfect isolation from the outside world. You must realise that such audiophiles would invest between $1000.00 and $3000.00 on a turntable and another $500.00 to $1000.00 on a moving coil cartridge. Those were exciting days in my long career.


Oh Jeeze Harry, now ya got me started. And how about SPEAKERS!! I still have a system in my house that I could crank up and blow the plaster right off the walls!! And it is 40 years old!! And unlike the flat, tinny, irritating sound of today.....it is music to carry you off to the heavens.
Unless its some big band stuff!! Ha!
My stuff has to stay with the house when we leave....ain't nobody can haul it out!:laugh:


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## Cassandra (Mar 15, 2006)

Two bits worth: How about putting a layer of 3/4" MDF on top of the concrete? The concrete would provide solid support to the MDF, while MDF would provide a softer, kinder landing zone for any dropped bit.

Of course, I would laminate the MDF top and bottom.

Cassandra


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## bobj3 (Jan 17, 2006)

How about just wiping off the butter off your fingers b/4 you pickup any router bits you jack wagon   

=====..


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## jschaben (Jun 21, 2009)

bobj3 said:


> How about just wiping off the butter off your fingers b/4 you pickup any router bits you jack wagon
> 
> =====..


:laugh::haha::laugh::laugh::haha::laugh: :laugh: :laugh: :haha:


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## Cassandra (Mar 15, 2006)

Next, I suppose you want us to stop eating that popcorn?

By the way, who you calling butter-fingers?

Cassandra


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## bobj3 (Jan 17, 2006)

HI Cassandra

Well if the shoe fits , Well what can I say :laugh::sarcastic:

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Cassandra said:


> Next, I suppose you want us to stop eating that popcorn?
> 
> By the way, who you calling butter-fingers?
> 
> Cassandra


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## harrysin (Jan 15, 2007)

sourdough said:


> Oh Jeeze Harry, now ya got me started. And how about SPEAKERS!! I still have a system in my house that I could crank up and blow the plaster right off the walls!! And it is 40 years old!! And unlike the flat, tinny, irritating sound of today.....it is music to carry you off to the heavens.
> Unless its some big band stuff!! Ha!
> My stuff has to stay with the house when we leave....ain't nobody can haul it out!:laugh:


Those sure were great exciting days Warren well before the "discount" stores when true Hi-Fidelity components could only be auditioned and purchased from specialised retailers who understood what they were talking about and systems didn't need huge sub-woofers which generally give headaches and bellyaches with their un-natural bass, seldom heard in an auditorium.


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## harrysin (Jan 15, 2007)

There is a term called "OVER ENGINEERING" which is what I think this thread started out as, but fortunately most of us aren't taking it too seriously.


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## gav (Oct 12, 2009)

Don't worry Harry, not even I was taking it too seriously.
Was just an idea is all.
I think really I just have an urge to cast something in concrete.
Maybe I could make a cast concrete frame for a homemade bandsaw.
2 crazy ideas in 1.
That's more like it !!

By the way Harry, seeing as you're a bit of an audiophile, have you heard of a t class amplifier ?
Audiophile sound at a bargain price.
http://shop.41hz.com/shop/
Check it out and look around at reviews if you've not heard of them before.


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## harrysin (Jan 15, 2007)

gav said:


> Don't worry Harry, not even I was taking it too seriously.
> Was just an idea is all.
> I think really I just have an urge to cast something in concrete.
> Maybe I could make a cast concrete frame for a homemade bandsaw.
> ...


An interesting site Gavin, but lots of smoke and mirrors I'm afraid. They are into switch mode power supplies, which for many applications are the way to go, but where audio is concerned it's my experience with amplifiers and CD/DVD players that high frequency artefacts are very difficult to filter out resulting in colouration. I still believe in large linear power supplies with huge reservoir capacitors that enable the guns in Tchaikovsky's 1812 overture to actually sound like guns.
I know of and understand how classes A, AB, AB1, AB2, B, C and D work but I'm blessed if I've ever heard of class T! 
That web site mentioned the word "class" in all specs. but failed to give a letter, odd!

Regarding casting Gav., just cast your mind on your forthcoming visit to OZ!


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## Ralph Barker (Dec 15, 2008)

bobj3 said:


> How about just wiping off the butter off your fingers b/4 you pickup any router bits you jack wagon
> 
> =====..


Been watching R. Lee Ermey as the therapist, have we? 

Drop a bit on the concrete table, and he'd have us in the dead-cockroach (or, dead-termite) position, holding a PC 7518 over our heads.


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## bobj3 (Jan 17, 2006)

HI Ralph

" Been watching R. Lee Ermey as the therapist, have we?"
Yes , hahahahahahahahaha
He cracks me up,,hahahahahaha, he would make a great one you cry baby..
I can hear him say " take two 45 slugs and call me in the AM " you jack wagon..hahahahahaha


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Ralph Barker said:


> Been watching R. Lee Ermey as the therapist, have we?
> 
> Drop a bit on the concrete table, and he'd have us in the dead-cockroach (or, dead-termite) position, holding a PC 7518 over our heads.


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## gav (Oct 12, 2009)

I think you need to look at some of the reviews of t class amps Harry. You'll be pleasantly surprised.


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## harrysin (Jan 15, 2007)

gav said:


> I think you need to look at some of the reviews of t class amps Harry. You'll be pleasantly surprised.


But WHAT are class t amplifiers, sure, my theory is a bit old and only really up to date to 2000 when I retired, perhaps someone like Howard with a similar electronics background to me will jump in and explain.

Quite honestly it reminds me of the "rave reviews" for super power cables that claim to enhance fidelity*, but the customer (substitute MUG) has a waiting time of I think a month to become accustomed to the change! So called "super 100% Oxygen free copper speaker cables, some around 1/2" thick are not far behind the power cables and fail every theory propounded.

* The one's who promote these cables fail to mention the miles of cables between the power source and the consumer's power point.
Sorry to be a pain Gavin but discussion makes life interesting.


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## bridger (Nov 26, 2010)

if you pour into an accurate mold you should get a flat enough concrete slab that you don't have to have it ground flat. cover it with high pressure laminate- formica or the like- and you'll have one beefy router table top.


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## merrittjm (Apr 7, 2012)

Not crazy at all. I am making an extension leaf with a router lift and using Quickcrete Precision Grout with color additive. The forms are MDF to allow layout lines, and will use 1/4" tempered glass to provide the smooth top surface.
I'll be providing pictures in the near future.


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## CygnusX2112 (Jun 3, 2008)

harrysin said:


> Now then, going back to my days in esoteric Hi-Fi, when Vinyl discs were the media, it was quite common to sit the expensive turntable on a Marble slab which in turn was sat on four squash balls, this gave perfect isolation from the outside world. You must realise that such audiophiles would invest between $1000.00 and $3000.00 on a turntable and another $500.00 to $1000.00 on a moving coil cartridge. Those were exciting days in my long career.



I still have all my old copies of "The Absolute Sound" and "Stereophile" in the basement. 1000-3000 on a turntable. 500-1000 on a moving coil cartridge. That would get you a system Harry Pearson would call "mid fi". I still laugh remembering how they would blast ol tin ears "Stereo Julian"/Julian Hirsch of "Stereo Review" and how he though for instance a .00001 THD Radio Shack receiver was better then a Audio Research tube amp......


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## paduke (Mar 28, 2010)

Back to fiberglass reinforced concrete table top. Go to home depot buy the cement backer board Its a machine poured cement fiber board It aint flat


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## barking spider (Dec 26, 2010)

Just a couple comments on this convoluted thread...
1. I have made a concrete counter top, and it can be made pretty dang flat. Flat enough for a router top anyway.
2. To worry about damaging a router bit if dropped on concrete top....... I don't know about you guys, but I don't drop my router bits very often. In fact, I don't drop many tools in my shop. However, If I was to drop a router bit, it would probably be during a bit change. Again, I don't know about you guys, but I don't usually try to juggle my bits while changing them. I think the chance of dropping a bit is pretty remote.

That said, I think it would be a terrible waste of time and energy to make a router top out of concrete, when there are so many better materials to use.


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## paduke (Mar 28, 2010)

barking spider said:


> Just a couple comments on this convoluted thread...
> 1. I have made a concrete counter top, and it can be made pretty dang flat. Flat enough for a router top anyway..


how did you grind your top? 

Was it Fiberglass reinforced or aggragate?


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## billg71 (Mar 25, 2011)

harrysin said:


> ..................
> 
> Now then, going back to my days in esoteric Hi-Fi, when Vinyl discs were the media, it was quite common to sit the expensive turntable on a Marble slab which in turn was sat on four squash balls, this gave perfect isolation from the outside world. You must realise that such audiophiles would invest between $1000.00 and $3000.00 on a turntable and another $500.00 to $1000.00 on a moving coil cartridge. Those were exciting days in my long career.


Harry, nowadays in the high-end audio world that $500 won't even get you started on an MC cartridge, much less a turntable:Stereophile's Products of 2011 ANALOG SOURCE COMPONENT OF THE YEAR, or maybe an Oracle Delphi Mk.VI turntable if you're heavy in the hip pocket. And they go up from there...

Just having some fun with the sidetrack, apologies to the OP... :stop:

Bill


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## barking spider (Dec 26, 2010)

I didn't use fiberglass concrete. I took a lot of time making the forms, lots of vibration and a lot of troweling/working on the surface as it set up. It's not a project I would probably do again, by the way.


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## DaninVan (Jan 1, 2012)

I agree with Bobj3 and Phil. Getting the top perfectly flat would be a pain in the a**.
What would you do down the road, should you decide to add some kind of modification? A huge amount of trouble for no particular gain.
Now, concrete kitchen countertops on the other hand...


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## paduke (Mar 28, 2010)

merrittjm said:


> Not crazy at all. I am making an extension leaf with a router lift and using Quickcrete Precision Grout with color additive. The forms are MDF to allow layout lines, and will use 1/4" tempered glass to provide the smooth top surface.
> I'll be providing pictures in the near future.


Doesn't temered glass shatter when scratched? Not that I endorse the idea at all but laminated glass (like a car windshield) would at least be safer


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## DaninVan (Jan 1, 2012)

Ok, I get it. You might consider embedding heavy grade expanded metal lath in the pour..1/3 up from the bottom (sounds like you're pouring upside down on the glass, so that'd actually be 1/3 down from the top as you pour. You can make the slab a bit thinner, and it'll be bomb proof.
MDF won't like the moisture factor and might bow as you 'vibrate' the pour; absolutely no advantage to MDF for a form!


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## ggom20 (Feb 1, 2012)

Hello!

Concrete top is feasable , but for what advantage ?

A router table or saw does not need being so heavy.

Some made concrete boats, advantage: cheaper.



Regards.
Gérard


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## merrittjm (Apr 7, 2012)

I'm placing the leveling grout today. I used 6x6 wire mesh, lapped over to make it 3x3 and will have it about halfway imbedded. I waxed the tempered glass with a silicone based car wax, and then wiped on a teflon coating. I made a small test piece on a small bit of spare glass, and when I popped it off of the glass three days later, the surface was so smooth you could see a reflection.
I used the tempered glass for safety. If it does shatter, it'll be in a thousand pieces and will be considered sacrificial. I will, of course, use eye protection and be holding my breath. Tempered glass does have a small degree of strength in tension, and I will go very slow and cautious.
On all of the inside surfaces of MDF I put Frog (masking) tape to prevent moisture warping the form. The reason I used the precision grout is that it is extraordinarily strong (14,000 psi compressive) and uber stable in all directions. 
I have my fingers crossed that the tempered glass will release as easily as the test piece. I'm going to let this set and cure for about 2 weeks before I flip it over to take the forms and glass off, and am hoping the daily temperature excursions (I live in Florida) will cause the glass to separate from the cement grout naturally due to their different coefficients of expansion.
Wish me luck, the adventure is just beginning.
jmm


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## merrittjm (Apr 7, 2012)

*Cement Table Saw Extension Router Table*

I made the pour, and, much to my surprise I was able to remove the tempered glass from the cured table without breaking it. The resulting surface was as slick and reflective as the glass, and essentially dead perfect flat across the breadth and width.
I have some lessons learned, and will be posting pictures when I make my quota of entries.
I am really excited about the results and will be making another table as soon as I tweak my procedures.
More to come,
jmm


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## ggom20 (Feb 1, 2012)

Waiting for pictures !

By the way, seen some ping-pong tables made out of concrete.

Regards


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## merrittjm (Apr 7, 2012)

The almost finished router table. I didn't make the mix wet enough, and that made a few voids in the surface. Using resin and crack filler to correct the issue.
jmm


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