Door stiles bow after assembly

Possible causes and solutions for door stiles that bow after the door is assembled. September 26, 2000

I am a furniture maker specializing in hardwood studies and bedroom furniture. I have been experiencing problems with some of the wardrobe doors I make. The stiles, when planed down to 22mm, are straight; yet when they have been made up into doors for a week or so, they bow in length.

I try to plane equal amounts from each side and I have checked the moisture content, which seems O.K. If this is due to drying stress, how do you ever obtain a perfectly straight stile?

Forum Responses
How tall are the doors? Itís quite difficult to get a piece to stay reliably straight/flat when the thickness-to-length ratio is high. In fact, most door makers wonít warranty doors over 48 inches high for warp.
Michael Poster, technical advisor

When we make doors over 36 inches in height, we make two panels instead of one, and add extra hinges. It would be my guess the panels are causing your problem.

To maximize the possibility for tall doors (long stiles) to remain straight, carefully pick lumber that is quartersawn and dry.

Are you jointing the face of your boards before dimensioning on the planer? If the rough board has a visible bow, and most of them do, run that face (the convex face) on the jointer first, until totally flat. That will help reduce the tension in the board. Then run it through the planer without flipping the board over.

The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor K:
Have you tried constructing your rails and stiles using three pieces to acheive proper thickness? I am building a maple door for our bedroom and the way I am building the stiles and rails is as follows; 7/8" aspen substrait with 1/4" solid maple on either side. With this method your stiles should stay relatively straight.

Also, if you are using solid wood panel... You probably know this already - you should alternate the ring pattern for each board, meaning you don't have two pieces with the ring direction running the same. Also use many narrow pieces to build your panel, around 2 1/4 - 3" wide. The most important thing to remember is that wood does have a memory and with changing humidity and dryness, one has to accept a little movement.