# flat surface for building a workbench



## VIFmike (Jul 21, 2012)

I have no flat surface to build my work bench. I had been using a steel table but alas it is not flat. I need to lay the two pieces of plywood flat so I can glue them up and screw them together. But for doing that and glue ups I have no flat surfaces.

I had a glass table but I cracked it doing a glue up so now I am gonna use it until it breaks all the way. Then I will let my kids shoot it. lol

Maybe there is a flat piece of concrete in my driveway that is not cracked.


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## woodnthings (Jan 24, 2009)

*Solid core slab doors are pretty flat*

Why not make a torsion box using 2 sheets of plywood? 
I did that and used 2 pieces of 3/4 particle board to make my outfeed table, about 9 ft 8 in by 30 inches. I used kitchen counter top stock to get the 10 ft particle board from a plywood supplier. 
I spaced the pieces apart using four straight 1 X 3's and glued them on one surface. Then spaced cross braces in between and all along the length. Then spread glue on all the edges and plopped the top on and weighted it down. :yes: Pretty darn flat and man it is stiff and strong.


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## Purrmaster (Jul 19, 2012)

I've nailed together some 2X4s to make a pallet for assembly of things. It probably isn't as flat as you need but a pallet can be a decently flat assembly.... thingie.

And woodnthings. That's an impressive piece of work you made. My hat is off to you.


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## VIFmike (Jul 21, 2012)

I think I found a spot decently flat and level in my driveway. I also have some 2" sch 40 pipe thats flat. I am gonna make some holders for it and set it up on blocks. Then I can glue up the plywood and add the legs upside down.

I really like the out feed table. I am making mine the same height as my TS. I wish I had that much room in my shop.

Oh and the glass table is only cracked on one side. I am gonna keep it for making smaller glue ups. It's a 60" wide x 24" tall piece of armored glass. It's about 1&3/4" thick and in layers of 1/4" thick glass with some laminate in between each layer. I was gonna make a coffee table with it but with the cracks it has become a piece for the shop.


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## cabinetman (Jul 5, 2007)

VIFmike said:


> I think I found a spot decently flat and level in my driveway.


That might be just enough. I've made many assembly tables that double as a bench, and the second side (underside) cladding for a torsion box is not that necessary. It can make attaching legs more difficult. I've used many different substrates for tops...Melamine, plywood, particleboard, and MDF. If you want it replaceable, you can clad it with tempered Masonite, and just pitch it when damaged to the point of needing replacement.

If you decide to glue and screw two sheets of plywood together I suggest this tip. Lay the eventual top sheet face down and place the bottom sheet on top of it. Line them up, and mark the edges as to which sheet is which. 

Then, use a countersinking/pilot bit to place your holes. Separate the sheets, and at every hole site on both sheets, use a countersink bit to just make a small chamfer. This will clean off any debris from the pilot hole, and create a clean area for screwing together. If this isn't done, just driving screws from one sheet to another could create some tear out which would prevent the sheets from coming tightly together.

If you are using two sheets of ¾" plywood, you would be using 1¼" screws. I would use a cordless drill on slow speed to drive the screws. You only have ½" of thread grabbing, and you don't want to spin the screws too fast, which could make them strip out the hole. When close to tight, just bump the trigger to tighten.









 







.


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## frankp (Oct 29, 2007)

Another option for making things flat is to simply use cauls. They are remarkably easy to use and work well. If you're worried about it you can do a winding check, which basically uses cauls (or winding sticks) at opposite ends of an assembly to check that the edges are parallel. Boat makers do it all the time to make sure the gun'ls are parallel.


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## H. A. S. (Sep 23, 2010)

Like Bill says, build a torsion box. I've made several of that style, back when I was moving around a lot; just not as large. Sturdy as hell.


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## jharris2 (Jul 9, 2012)

frankp said:


> Another option for making things flat is to simply use cauls. They are remarkably easy to use and work well. If you're worried about it you can do a winding check, which basically uses cauls (or winding sticks) at opposite ends of an assembly to check that the edges are parallel. Boat makers do it all the time to make sure the gun'ls are parallel.


Is this a sighting or eyeing method?

Do you sight the top edge of the caul in the foreground with that of the caul in the background to make sure the lines are on the same plane?


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## VIFmike (Jul 21, 2012)

Yes, I will be putting the top sheet face down and then screwing them together with glue as well. I will drill pilot holes and use the clutch on my Dewalt cordless to make sure they are not too tight. 

Got any pics of these cauls? or pics of other methods?


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## frankp (Oct 29, 2007)

jharris2 said:


> Is this a sighting or eyeing method?
> 
> Do you sight the top edge of the caul in the foreground with that of the caul in the background to make sure the lines are on the same plane?


Generally eyeballing it is good enough for boat building. Either way, the process you describe is how it's done. Make sure the top edges are parallel to each other and you're golden.


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## Masterofnone (Aug 24, 2010)

woodnthings said:


> Why not make a torsion box using 2 sheets of plywood?
> I did that and used 2 pieces of 3/4 particle board to make my outfeed table, about 9 ft 8 in by 30 inches. I used kitchen counter top stock to get the 10 ft particle board from a plywood supplier.
> I spaced the pieces apart using four straight 1 X 3's and glued them on one surface. Then spaced cross braces in between and all along the length. Then spread glue on all the edges and plopped the top on and weighted it down. :yes: Pretty darn flat and man it is stiff and strong.


I see two table saws and two band saws. I aspire to be like you... :yes:


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