Somewhere between the purchase of my home (approx 30 years old), taking the kitchen cabinet doors of so I could repaint them, and hanging them back up, they became warped and do not close solid at the top or the bottom of the cabinet. This did not happen to all the doors, just about 3 of them. So, the question is, how do I get the warp out of these doors? I started to try the standard Funk and Wagnalls approach but deicded I don't have a book big enough. The doors are fairly standard sized (~1/2 to ~5/8 in widths). I do not know the kind of wood. That is really about all I know. Any help would be greatly appreciated.
I am willing to bet you painted only the outside of the doors or you put more coats on the outside. Wood warps when mosture is higher on one side vs the other. The convex side has more mosture than the concave side. The best thing to do is strip the finish off. and allow the wood to be in your home environment so that air can get to all sides equally. You might spray a light mist of water on the concave side. The wood should go back to its origninal conture. Then reapply the finish to all sides equally.
Well, now comes the full confession. All I have really done is put a coat of primer on both sides of the door. I am new to all this stuff and didn't realize how badly a water-based printer and paint stick to an oil based paint. SO, once I realized the new paint was not going to stick, I stopped. When I hung the doors back on the cabinet, some of them were warped. Although I can't say exactly how much primer I put on each side, I basically just put one coat on each side. The reasons for this probably won't interest you but they involve a wife and three babies that were needing to move in and I was running out of time. I have wondered if there was excessive moisture in the garage where I did the painting. But it seems like the moisture would be equal on both sides in that environment. Anyhow, I will try what you have suggested.
The water based primer is the cause of your problem. Where you painted them you must have stacked the doors in such a way the air flow was different on one side vs. the other. One side dried more than the other. What I would do before you do much of anything is take a couple of 2X4's and cut slots in them the same width as your doors. Put the 2x4's on the floor and place the doors in the slots for a few days. The air flow will help to straighten them out.
Wood is alive and will continue to move forever. That is the most important thing to learn in woodworking. You always need to know that this will happen and use it to an advantage not a disadvantage.
Here's a couple of things I've learned the hard way:
When I'm done working on a project for the day, I set my wood on edge, never flat down on the widest faces. The moisture in the air will enter the wood unequally and the wood will warp. If you need to stack your wood, cut small pieces of wood (called stickers)to place between the wood so air can flow equally around it.
Also, concrete contains moisture that will wick into your wood if you lay your pieces down flat on the garage floor. That wood will warp.
I've had fairly good success with warped pieces by laying them out on the lawn in the sun. The wood will warp or cup towards the sun so monitor it's progress after about 30 minutes or so. When it straightens out, take it back into the shop and let it acclimate for a day. If some of the warp returns, take it back out into the sun and try again.
Good luck and don't bemoan your fate too much. Wood warps for all of us...