How do I clamp 2 pieces that are 10 ft long?

If you have some place long enough, you can use wedges in lieu of clamps.

Here’s the idea. But you’d have to scale it up massively.

-- Chunk's Workshop pictures: http://spadfest.rcspads.com/thumbnails.php?album=135

take some scrap boards and make up some hook extensions, just take a 16” board, glue and screw a 2” block to one end, and another block to the other end on the opposite side, to get a one foot extension. I know you need 2 feet, but I would put one of these at each end of each clamp so it sits straight, rather than one end being flat, and the other raised on the extension. if your plywood isn’t going to be a finish surface, you can simply screw on a few blocks near the seam and clamp them together.

If you’ve got pipe clamps you can use them in pairs with the ends grabbing each other and spanning the whole length.
another method is to clamp a board across the sheet parrellel to the glue joint on the larger piece using some small clamps and then hook your clamps over that. If you do this you’ll also need some cauls to keep it flat.

-- Don - I wood work if I could. Redmond WA.

@drewnahant. I forgot to mention that my 8’ clamp is a pony type pipe clamp. I am having a hard time envisioning your suggestion drewnahant.

@ChunkyC. It might be too massive to scale it up I think.

-- Northern California http://www.lloydus.com

look at this bench hook, same idea, but longer and narrower
http://lumberjocks.com/projects/3000
though if you have enough bar clamps, hooking them together is probably going to be easier, I have some of the extension setups because I have limited clamps and use them regularly, so they are very handy for me

You can use rope like you would a tourniquet.

I would run a groove along the two edges and add a spline for strength.

-- Gary - Never pass up the opportunity to make a mistake look like you planned it that way - Tyler, TX

I agree with the pipe clamp idea. Put the two clamps together like you would when you hook your pointer fingers together and pull. Or Don’s idea is good too, just pulling on a slight angle.

Or use pocket screws if visibility isn’t an issue.

How much pressure do you really need anyway? It’s not like that joint is going to be very strong, usually people over torque their clamps.

-- some day I hope to have enough clamps to need a clamp cart!

We got you covered Lloyd. Here is a cheap easy fix that Bob Simmons came up with. This will work perfect for your project. Genius. Check it out.

http://lumberjocks.com/daddymunster/blog/21318

-- david roberts, spinning Tales from Topographic Oceans, no, really.

Here’s the stuff!

-- Chunk's Workshop pictures: http://spadfest.rcspads.com/thumbnails.php?album=135

Maybe I’m hearing you wrong but are you actually trying to butt join two sheets of plywood? If you want a 4’ x 10’ sheet of continuous plywood you scarf it. You don’t need any clamps at all. you can use staples through 1/4 plywood strips and remove them after the scarf sets up. Check out this blog entry:

http://lumberjocks.com/shipwright/blog/19783

-- Paul M ..............If God wanted us to have fiberglass boats he would have given us fiberglass trees. http://prmdesigns.com/

Paul hit the nail on the head. I can’t imagine a butt joint in plywood having any strength to speak of.

-- Charlie M. "Woodworking - patience = firewood"

Hold it – I forgot to mention pocket hole screws.

-- david roberts, spinning Tales from Topographic Oceans, no, really.

If you are using “Pony” clamps, whether its on 1/2” or 3/4” pipe, just head down to the HD or other plumbing supply house and pick up a few more sections of pipe and some couplings, extend your current Pony clamps into what ever length you need.

My standard pony clamps are 3’ and 5’ pipes, but if I need and 8’ or 10’ clamps I just screw on the coupling and pair up the pipes for the length I need for the job.

-- James

@shipwright. I think your suggestion makes most sense for a strong joint. Any idea how I might cut plywood at that kin of an angle? My table saw doesn’t go much past 50 degrees and I can’t stack it on it’s end. Can you plane plywood at that angle I wonder? I have a hard time thinking I will be able to keep the angle of about 11 degrees consistent across the 4’ width of the plywood.

-- Northern California http://www.lloydus.com

It is pretty easy to keep the angle constant. The layers make bands across it..

You clamp them down with the faces together. Mark off the overlap on both. (The bottom one will be sticking out the overlap distance.

Longer tutorial from Duckworks Magazine:

http://www.duckworksmagazine.com/07/columns/nichols/index3.htm

-- Woodworking shouldn't cost a fortune: http://lowbudgetwoodworker.blogspot.com/