I need some advice, I have a problem with a warped panel, its 1/4 inch birch ply mounted on a frame of 1 by 2 white pine, the size of the panel is 30 inches by 24 inches. Its glued and nailed to the frame. I use these panels for painting on. The painting needs to be in a show in New York in a few days, but when hanging on the wall one corner sits off the wall at least an inch. Temp change I believe led to the problem. I build these all the time and never had it quite this bad. I screwed a few cross braces in after the warp( while bending it flat) did'nt work, also screwed in a 1/2 inch oak backer board, too heavy. Any advise on how to deal with this would be greatly appreciated. Thanks

Wow, that sounds like bad news. I don't think there is much you can do. If the plywood warped, your screwed. If the frame warped, you can try to build another one and replace it. Most of the time when you put a panel inside a frame, you shouldn't glue or screw the panel. It should be floating inside the frame. Because it leaves it free to move, so if the frame shrinks it won't bow the panel. And if the panel swells it won't blow the frame apart. Although, I didn't think this applied to plywood panels, but it sounds like it does now. The best I can suggest is to try another frame.


Maybe someone else can offer a better solution before your deadline.

Later,
Rob

If having a back on this assembly is no big deal, cut a piece of 1/4"-thick ply (or there abouts) lay the frame on a flat table, lay a bead of glue around the edge and press the new ply to the back. Staple or brad the backer in place while it is pressed flat.
I'd also lay a bigger piece of ply over the assembly and weight it until the glue dries.
The second piece of ply on the back makes it a box which should be very rigid, and flat.

__________________
Tom Hintz
www.newwoodworker.com