Is there a way to flatten warped hardwood cabinet doors?

Question

I painted my kitchen cabinets, and afterwards, close to half of the doors don't sit flush against the cabinet. It doesn't make much sense, but I suspect the painting process may have warped the doors a bit? (I used Stix primer to hopefully head against this, recommended by the guy at BM) They are a very hard wood (maybe red oak?). Does anyone know of a way to work on getting the doors flat again? Seems like something like steaming them somehow and then applying force in the right direction using a clamping system might work, but I would love input from someone who's dealt with something like this before.

Note that I also replaced the hinges, but I don't think they are the problem, since if i take them off, the raw door still does not lie flat against the cabinet. I'm including a photo of a problem door as well as a good one for comparison.

EDIT: adding a photo of the same problem door from the inside where you can see the shim I added to the hinge. Without the shim, the cabinet door does not sit flush on the opposite corner. I came upon this solution by putting the door on a flat table and observing that when I do that, 3 corners touch the table but the fourth does not (it's elevated). If I push the elevated corner down, the corner diagonal from it comes up instead. So I had to pick which corner of the door does not sit flush against the cabinet, and the corners with the hinges are less noticeable (and, possible to shim). But, it's still a bit of a sore thumb and now I'm wondering how to fix it altogether. Also adding a photo of the original cabinets.

Thanks!

Answer 1

TL;DR:

You can do it, but this isn't going to be an easy project.

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Bending wood involves one of two processes. Either you cut a board into very thin slices that can be individually bent without breaking, then glue these thin slices back into one solid piece of wood while bent around and clamped to a form to hold them in the bent shape, or you steam the piece of wood until it's flexible enough to bend without breaking, then you clamp it around a form until the wood dries and holds its shape.

You're not likely going to want to attempt to slice your cabinet doors up and reglue them, so that leaves you with steaming.

• You would need to remove all finish coats back to bare wood
  • This includes the new paint, any old paint/varnish/urethane/etc.
• You would then need to build a clamping jig that is slightly warped the other way.
  • Steamed wood will hold its shape, but will tend to "bounce back" a little bit.
  • If your jig is absolutely true flat, the wood will tend to have a bit of a curve when released. If it's just a bit beyond flat in the other direction, that "bounce back" will get you pretty close to flat.
• You would need a large steam box.
  • You can look up specifics of how to build on on the internet, but basically, it's a large plastic box into which you would put the door. Traditionally, steam boxes were built of wood, but plastic is probably easier these days.
  • The door would need to be supported on a few points, not lay flat, in order to allow steam even access to all sides.
  • You would need a source of a lot of steam.
  • You would need a way of piping the steam into the box and a valve to let it out so it doesn't pressurize and blow up. (Steam pressure can move million pound trains...)
• Once the wood is thoroughly heated and moistened through, you remove the door from the steam box and clamp it to your form.
  • Again, the form would need to support the door in spots to allow for even cooling and drying. A full support under the door would keep that side wet much longer and possibly cause bends/cracks in the other direction.
• Once the door is thoroughly cooled & dried, you remove it from the form and hope you've got the opposite bend correct so that it springs back into shape pretty close to flat.

You may be able to find some info on how much "bounce back" to expect, but it's probably going to depend a lot on the species of wood, and you have to know that each branch on each tree is a different bit of wood and that each one will be slightly different.

Answer 2

Most cabinet doors are glued together panels...using steam will ruin the glue joints. The safest approach is after taking panel to bare wood place the panel on a sheet of plastic on a work bench concave side up. Thoroughly wet top side of the panel and clamp down flat or shimmed to remove spring back. Keep wetting the wood over the course of a few days. Using the table of a 10" contractor table saw makes clamping really easy.

Answer 3

I bet they were leaned up against a wall. I just did this to mine on accident for 3 weeks painting the hardware and now they are mostly all bowed.