Expert: Jamie Yocono - 1/14/2010

Question
Im making  kitchen door fronts out of oak but they are bowing could you give me any advise on how to stop this
Many Thanks gary

Answer
Gary,

I am assuming that the door fronts you made are slabs of solid wood, that were all edge glued together. If they're bowing, my first thought is that you didn't orient the annual rings properly to ensure a flat door.

When gluing up a slab, the annual rings on the wood should be alternated, which compensates for wood's natural cupping. Now some woodworkers claim that this doesn't make a difference, but I believe it does. If all your boards have their rings facing the same way, your door is sure to cup.

Here is a somewhat easy correction - follow this link : http://4.bp.blogspot.com/_GsOfctqVvXc/Sy5pJ2bINuI/AAAAAAAADBU/RLbrlOI18zc/s1600-...

If you can get the board to lay somewhat flat, by doing what this image suggests, then I would try to attach a straight edge (board) on the back side of your doors, to keep it flat. You can probably get away with something like a 1 x 2, placed on edge, to utilize it's strength, much like a floor joist is placed on edge. Screw this board directly into the back of the door, making sure it doesn't interfere with the interior shelves or the hinges. You may want to elongate the screw holes, so that when the door expands or contracts, the screws can "float" a bit in their holes. If you don't elongate the holes, your door might split when it expands with season changes in ambient humidity.

I've been able to successfully straighten out cupped boards by attaching a straight board to the back of them. But you'll have to clamp the two boards together, first. It's a little tough to do, and you need good clamps, not flimsy or weak ones.

So here's your sequence

- flatten the door (as shown in that picture)
- clamp a straight 1x2 to the back of the door
- attach it with screws, then unclamp

Your door should remain relatively flat with this brace on the back of it. DO NOT GLUE IT IN PLACE, it can only be screwed in place.

OK, hope this helps. Write back if you have any questions.


Jamie Yocono
Wood It Is! Custom Cabinetry
Las Vegas, NV
www.wooditis.com
My woodworking blog: www.wooditis.blogspot.com