Concrete Workbench top?

[motionclone]

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[ccoon520]

Concrete doesn't do well when suspended in air for the most part especially with shock loads. A table/benchtop act in tension when loaded both wood and metal excel in tension due to their grain structures. Even though they don't excel in compression by the time the load is transferred through the legs of a wooden or metal table it is distributed across a much larger area reducing the shock lessening the load.

There are a lot of buildings that use concrete for floors but they have to put a significant load on the rebar before the concrete is poured and then after it sets they remove the load. This then puts the concrete in compression (a state that is very strong in) and allows it to carry the loads the building will experience during its lifetime.

I do not know how much of a load you would need to apply but if you can do so then your benchtop would be near indestructible. However, if you can't and you use the persuasder (aka the I'm annoyed hammer) and hit in the wrong spot you may split your benchtop clean in two.

So there is a way to make a very very strong concrete benchtop but you have to be patient and have the ability to preload the rebar to force the concrete into its preferred loading state.

 

[NHSleddog]

You will love it. Assuming you also have a steel bench somewhere as well.

Downsides: They require a SUBSTANTIAL frame. They are always cold. The edges do tend to chip. They don't like extended direct torch contact. They don't make a great welding bench.

 

[PapaJ]

I found out the hard way one time what happens when you weld on porous concrete. I was being lazy and trying to weld a gusset on a trailer frame without removing it and taking it to the bench. When the air pockets in concrete heat up, it explodes on you. Scary the first time it happens. I learned my lesson, so it hasn't happened again.

 

[motionclone]

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[BigG]

The have never seen a concrete bench in any of the shops that I have worked in or been around. The characteristics of concrete would seam to make it a no go for me. The worry of cracking the concrete. Having to lay a piece of wood under something to pound on it or drill into it. Cold in the winter.

A wooden bench is less likely to crack. Drilling into it is not a big deal. Need to add a bench top tool like a drill press or second vice can be easily be done. Laying out a fixture to the wooden top could be screwed directly to the wood. Easy to refinish. The metal edge could be added or the edge piece of wood could be easily replaced. Shelves under the bench would have more room for storage. Moveable if your needs change. The chance of damage to a sharp edge such as a chisel or router bit are reduced. etc

 

[mikester]

Anyone here have or have used or been around a shop with a concrete workbench top? Any downsides?
Im considering putting one into my new to me 32x40 shop.
I have space layed out for about 14' long by 36" deep bench.
Im thinking 4" thick. Lumber is real expensive now and im a mason so id build it out of block then pour a 4" top full of rebar and angle iron for a front edge.

I'd prefer steel plate or wood over concrete. Steel works good for welding tables, clamping fixtures etc. Concrete is only good in compression and when it breaks/cracks you are FUBAR. Not much good for hammering or clamping onto. Quick way to dull your drill bits. Concrete spalls if you apply too much heat so welding and torches are out.

 

[85Hokie]

Not really planning on putting anything heavy on it just using like a workbench for disassembly/reassembly of parts, mount a vice on one end etc.


Ive never had a steel bench always been wood. Id consider building a steel bench but im thinking it would be more expensive than block and concrete. but maybe not.

I would build the bench supports out of 8" block rebar pinned to the concrete floor and then block cavities filled together with with the top. 1/2" rebar throughout and 4000psi crete. I build fireplaces and chimney foundations this way sometimes.

As far as chipping the edge I was thinking to put a 3x3 piece of angle steel the length of the top front edge and embed into the crete.

MC

Being that you are a concrete person - and know how to prep it and finish and seal it - I would say go for it.

Beating and banging on it might be a no-no but far as being a nice flat smooth work surface it would be the cats ass.

Having the pre made holes for the vise might be easy to do - but I would make sure that corner can never be under a tremendous load. Maybe have a rubber mat under the vise once clamped down to absorb some hammer blows through the vise. Or even having the vise mounted to something else that is portable - like many do on an old rim pedestal.

On the 4k PSI - you going to bag mix this or somehow have truck transport it? You gonna need about 24 bags (1/2+ yard) of #80 crete as I am sure you know !

I once poured a sidewalk over a yard ..... bag mixed it with a friend..... on a sunday.....28 years ago.... I am still sore from that day!

I would like to see the finished project !

 

[NHSleddog]

This will help,

 

[85Hokie]

This will help,

View attachment 53241

Dayun thats nice shyte! Whats that puppy cost? 2.5K?

EDIT - looking that up ..... really not a bad price - if'n you do a lot of concrete !!

https://www.everythingattachments.com/Tractor-Cement-Mixers-s/10652.htm

 

[Henro]

I am in the build "the concrete workbench" group.

Cannot help but think if not satisfied with it, it would be a hellava base, and you could cover the top with either 1/8 inch thick steel sheet or plywood, later, without adding much height.

I give your idea

 

[RCW]

Motion - -

I'm with NHSledogg, Hokie and Henro. You obviously know what you're doing - - go for it. Like Henro said, cover it with another material if needed, but I'm willing to bet you can make it work.

I'd be curious how you do it, and please post some pictures.

I wouldn't try it, but I don't have the knowledge and experience you do.

I know some novices that have done kitchen counters, but that's not subject to the same abuse your workbench will.

 

[motionclone]

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[Lil Foot]

https://www.youtube.com/results?search_query=concrete+workbench

 

[North Idaho Wolfman]

im in the process of sheathing with 5/8 plywood and building shelving while im at it.

Why 5/8 plywood, that's some serious $$$.
Why not 5/8 drywall or hardi board, way cheaper and fire proof.

 

[motionclone]

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[NHSleddog]

Dayun thats nice shyte! Whats that puppy cost? 2.5K?

EDIT - looking that up ..... really not a bad price - if'n you do a lot of concrete !!

https://www.everythingattachments.com/Tractor-Cement-Mixers-s/10652.htm

150.00 at Harbor Freight and I welded a 2" Hex repair collar into the base of it.

The Auger motor was 1400.00. I use the motor primarily as an auger to drill holes. I have drilled at least a thousand holes with it, no exaggeration.

 

[NHSleddog]

Andrew Camarata on Youtube has concrete benches in his shipping container castle.

 

[old and tired]

Jesse is a friend of Andrew Camarata, mentioned above. You can fast forward through the slow parts...

 

[Botabart]

Anyone here have or have used or been around a shop with a concrete workbench top? Any downsides?
Im considering putting one into my new to me 32x40 shop.
I have space layed out for about 14' long by 36" deep bench.
Im thinking 4" thick. Lumber is real expensive now and im a mason so id build it out of block then pour a 4" top full of rebar and angle iron for a front edge.

This is funny. I just watched a Jesse Muller YouTube video on concrete workbench about an hour ago. Check it out.