Looking for solutions

[Jim Tobias]

Box is walnut. Top is Wenge frame around a panel of Mappa Burl veneered piece of MDF.
OK, I did everything like I always do before assembly and finishing and now I have a warped frame on the top.
It's a small box (11.75 X 7.75). The panel is veneered on both sides and has been setting in shop finished for probably a year. I glued up the frame around the panel and it probably set in shop for another several months. I Attached it to the box with hinges and sanded all points of contact flush. At this point, it was totally flat and fit perfectly.
I took the box apart and finished with several coats of Waterlox and it has been curing for a couple of months. I rubbed the finish out to a soft sheen and then reassembled and now the problem appears.
I don't know what caused it.....I wouldn't think applying finish would warp the frame?? Never had that happen before.
Humidity levels in my shop are normal (45% - 55%) and temp is controlled also.
Any suggestions on how I might correct this without tearing it apart and starting over??
I brought it into the house a few nights ago to see if a miracle would occur and there would be any difference..... so far, no change.
Any Ideas??

Jim
306530

[Jay Jolliffe]

Nice box...Don't have an answer for you but I question the humidity of your shop. To me that looks kinda high but I don't know what it is in mine. Maybe I should get a humidistat to find out.

[rudy de haas]

hi:

I have a dumb question instead of an answer for you - sorry. The picture suggests your wenge edging changed, but wenge has only
a 3% radial (6% tangential) shrinkage so, unless this thing sat under a drip for a long time, it doesn't seem as if it should have done this.

But, if it didn't what did? Did you use a piano hinge? and, if so, could it be binding?

[Jim Tobias]

Jay,
That is average in the shop. I have a floor model dehumidifier and keep it set on 45%. On a rainy day it might climb to 50 but the dehumidifier handles it pretty well.
Jim

[Jim Tobias]

Rudy,
That's what has be baffled. The hinges are 2 Brusso hinges and the top does not bind. The box and top have been sitting on a quilt on top of a table in the shop for months. No water drip or moisture issues that are visible. The only thing I did to it was apply Waterlox Original Sealer/Finish.

Jim

[rudy de haas]

Have you used other pieces from the same batch of MDF elsewhere?

Several years ago I put 2" wide strips of 3/8th plywood about 1" apart on a floor to make channels to put heating cable in. After the travertine went on the plywood exuded some chemical goop (turned the thinset almost white within two weeks of setting the stone) that caused the insulatilon on the heater cables to rot and the plywood itself to twist badly. Made in China... could something similar be happening to you?

[Jim Tobias]

I don't think so. The panel had been veneered and setting in shop for over a year before I assembled the box. When I assembled the box, it was totally flat.

Jim

[Tony Joyce]

Tough call, but my guess would be the panel is the cause. The frame is not heavy enough to warp the panel or hold it flat.

BTW, How thick is the top panel?

Tony