Best way to straighten warped plywood?

[Nocturnaloner]

Alright, my near-total ignorance of woodworking will be on display here, but I need some help!

While putting together the parts of my cabinet, I noticed that one of the sides has a noticeable curve to it.  I figured it was pretty common for plywood sheets to have some waviness to them, and that it would straighten out as I screwed the ledgers and cross-braces into place.  Famous last words.  Now I can't fit the marquee into place, because the bend at the top of the side panel is severe enough to throw the top of the cabinet badly out of square.  Anything I can do to fix it?

[Crazy Cooter]

Warped plywood is not good.

You can try to use screws and extra braces to get it back, but like I said:
Warped plywood is not good.

Take a pic of what's wrong and I (or someone else) might have an easy fix.  i.e. gouge the wood, jam a "spreader" piece of wood in at the top,  etc.

[whammoed]

Depends on how bad but if there is a slight curve in it you can brace it in some way so it is straight and after some time it will stay straight.  For quicker results it can be bent in the opposite direction and kept there for a little while until it returns to a straight position when the bracing is removed.  I have straightened out small bends in just a few hours by placing the board over two 2x4s curve side up with a weight in the middle and a light misting of water on the plywood.

[Flinkly]

comming from a woodworker, warped plywood is a common thing unless you buy the really expensive stuff, but being arcade hobbiests, we tend to spend our dollars on other things.

[Nocturnaloner]

Don't have a working camera at the moment.  Would a handscrew type wood clamp help to take the bend out while I brace it?
http://www.toolking.com/grip/view.asp?id=3937

Flinkly, you're right, there is no frame as such, and the 'ledgers', or what I am screwing my cross panels to are only 3/4" square.

Whammoed, thanks for the tips.  I may have to take the whole thing apart to get this right.

[Flinkly]

just to add to your situation, if you uise the wammoed way, you might gain your warp back over time, since it's just a temporary fix and you don't have much frame to speak of...

sorry to make things worse, just thought you'd like to know.  although your cab should stay pretty straight when you've got it all together.  notice that i said should.

[Shape D.]

If you want it as flat as it will get you will need to get it wet and use clamps to hold it flat. the water will make the wood plyable and bend into shape. When it dries it will end up flatter.

MAKE SURE IT IS THUROGHLY DRY.

or else your screwed

Holy crap I suck at spelling.  I can tell its wrong but I don't know how to spell it right.

[Gunstar Hero]

Fire. Spread the ashes out flat. Then buy new plywood. 

[SirPoonga]

for the price of a sheet of plywood, I'd just buy a sheet instead of fix.  You could use the warped one to make smaller parts.  It's easier to straighten out smaller pieces of wood, at least in my experience.

[Nocturnaloner]

So, just like Gunstar's suggestion then, but without the burning...

I knew you guys would get down to fire eventually.

Seriously though, thanks for the help, I will let you know how it goes.

[Gunstar Hero]

I knew you knew... and I hate to leave people hanging.