My plywood cabinet doors are warping- what do I do now?

[dennis thompson]

I built two 3/4" plywood cabinets for our laundry room about two months ago. They are painted. Two of the doors are warping pretty badly. Any thoughts on a fix of the current doors (I'm not hopeful ). Do I need to replace them, what wood would you recommend I use? How to prevent this in the future?
Thanks

[George Bokros]

What kind of plywood did you use? I would think Baltic Birch would be more stable than ordinary ply.

[Andy Giddings]

Not sure whether the doors you are talking about are plywood panels inset into a real wood frame or not? I've never used ply alone as a door, always gone with a frame and plywood panel construction and not had any issue with warp. Normally for painting I would use Ash or paint grade Maple for the frame with a BB panel

[mreza Salav]

Laundry is a place with lots of humidity and heat change. Not sure if you can salvage the doors, you can try clamping them down on a bench/table with extra wedge under the "low" corners (press down the opposite corners) more than keeping it just plane and let it sit in the clamp for a week or so. That helps to take the wrap out but not sure if it lasts.

[David L Morse]

If the hinges can handle the weight some battens disguised as shallow shelves or racks might help. They could hold drier sheets, color catchers, instruction manuals and other small stuff that typically gets lost at the back of deep shelves.

[J.R. Rutter]

MDF

Shellac the heck out of it, especially the edges, with multiple coats. Then scuff sand with fine grit and paint.

[Robin Frierson]

I would try some hardwood cleats, also called battens, on the backs of the doors to keep them flat. Maybe three 1in wide should do it. Next time consider plywood captured in a frame.

[Jim Becker]

I had a slight issue with that with the taller, upper doors on my recent buffet/hutch project and solved it with putting a strip of 3/16" thick x 1.5" wide steel across the the doors on the inside. The material drilled easily on my drill press and I used pan-head screws to avoid having to countersink in steel. That said, if you have a severe warping issue, then you'll want to consider replacing the doors with higher-quality material.

[Sam Murdoch]

Plywood doors rarely work unless they are set up to close against a solid catch or magnet stop at the top and bottom.
Laundry environment - as has been said - is a high humid high, heat environment - so you are up against it from the get go.

A solid frame and panel door is the best way to go - those too should be stopped with catches - in anticipation - especially in the laundry.

What to do now?

A few options that could work for you:

1) Mill out some hard wood 1x2 or 1x3 battens. Thicker is better, but more importantly, introduce an opposing curve in them to counteract the twist in the door. I call these banana battens.

2) Go to the box store and buy a few lengths of steel angle - 1-1/4" or 1-1/2". Pick straight ones - as short as will do the job. (In any case - using wood battens or iron - I recommend that you always start with the shortest length you need. Don't use 8' boards and try to mill those straight then cut them down do 36". Simply mill your 40" piece straight then cut to length. This insures that the piece you milled will stay straight. Same goes for steel (kind of) buy a 3' piece rather than an 8' piece and cull from the stock so that you choose the straightest.) These are rigid enough to overcome the twist in the plywood. Drill and counterbore the steel away from the doors then apply with short screws and maybe a bead of PL adhesive.

3) Build new frame and panel doors.

Good luck.

Sam

I was typing as Jim was posting

[dennis thompson]

Thanks for the advice, I think I'll build new frame & panel doors

[Jim Andrew]

Years ago, I used to build cabinets and used 3/4" birch ply for doors. One house had several doors that just went crazy, so I built some new ones. Laid the warped doors down in the shop, and a few months later noticed they had gone back flat. So it is just some green wood in the plywood going crazy, and after while they will probably straighten out.

[Frederick Skelly]

I agree - install wood or metal battens.

Interestingly, my grandparents built a house in the 60s that had oak plywood cabinets and doors throughout the kitchen and laundry. No frames - just flat, 3/4" plywood that was routed on all edges and rabetted on the back so they would overlap the openings a half inch on each side. Those doors never had a bit of warpage in the many years they lived there. It was just a good grade of regular oak plywood - not lumber core or baltic birch. Dunno.

[fRED mCnEILL]

This is probably the wrong time of the year to suggest this but when I get a piece of plywood that has warped( I build tack boxes(trunks) out of plywood) I put it on the lawn in the sun with the cupped side down to straighten it. The piece absorbs moisture from the lawn and the sun causes loss of moisture on the other side.(it can happen quite quickly) The other way for smaller pieces inside is to stand it upright and use a heater with a fan to blow on the cupped side. It evaporates the moisture and causes the board to "warp" in the other direction. Then coat with paint, etc.

[Robert Engel]

Thanks for the advice, I think I'll build new frame & panel doors

Best choice!!

[Osvaldo Cristo]

I built two 3/4" plywood cabinets for our laundry room about two months ago. They are painted. Two of the doors are warping pretty badly. Any thoughts on a fix of the current doors (I'm not hopeful ). Do I need to replace them, what wood would you recommend I use? How to prevent this in the future?
Thanks

One stupid question: did you paint both sides of the doors

If you painted a single face it is much probable the different humidity absorption between the faces was responsible for warping.

Anyway I think your decision to construct new doors is the simplest and easier way to go.

All the best,