How to Straighten Warped Plywood
I thought that the whole point of plywood was that it couldn’t warp, but I have some that has done just that. Is this a manufacturing defect? If not, is there anything I can do to correct the problem or work around it?
Marc Alfant, Melbourne, FL
The belief that plywood doesn’t warp is common, but mistaken. Even if the sheet is flat when you buy it, it often will cup or twist in your shop. But unless it is intended for a spot where it won’t be fastened down, like an adjustable shelf, you can still use it.
Here are a few tips: If the warped piece will be the top of a cabinet, put the crown on top. It’s better than having a top that sags. Face the crown in on the sides of a cabinet, as the shelves will push it out.