Expert: Jamie Yocono - 4/22/2004

Question
I would like to know how to glue up furniture doors and keep them from warping. I just finished two doors for a pie safe. one door is fine the other is warped. All the joints are square and all pieces ar the same length.  Is there a special way to clamp to keep them from being warped (clamp to tight?). Thanks

Answer
Hi Neal,

There are a few ways that I glue up doors to make sure they're flat and true. It really depends on the type of joint that you're using.

For example, if I make a door with half lap joints at the corners, I use 4 C-clamps that exactly the same size and make. That way, with a clamp on each corner, the door sits perfectly flat while drying. You have to make sure that you glue the door on a perfectly flat surface, such as a workbench top, or a tablesaw top. Put some newspaper down first!

If you're using bar clamps to glue a door, you (once again) need to make sure that you use 2 (or 4) identical clamps, and that you're on a nice flat surface. With a straight edge, check the two opposing corners, sighting the straight edge in relationship to your door. It's sort of hard to explain, but with straightedges, you'll be able to see if you have a high corner, or if your wood is lifting or bowing somehow.

With bar clamps- another important thing to do is make sure your door is pressed down flat again the bars. If the bar clamps are the same, and you're on a flat surface, the door will be flat if it's pressed down again the bars.

Now some people will argue that bar clamps have "sweet spots" and that if your door is thin, you'll be missing the sweet spot on your clamp bumper. This is true. So some woodworkers use long scrap wood blocks to even out the clamping surface on the door. This is often hard to do, as you need three or four hands.

My best advise with bar clamps- use clamps that are the same, press the woods down flat into your bars, and then "sight" the door, checking for parallel sides and ends, with no raised corners. A raised corner will result in a warped door.

Hope this helps, feel free to write back if you think of anything else. Good luck, clamping doors is a challenge!

Jamie Yocono
Wood it Is! Custom Cabinetry
Akron, OH