Help required to straighten plywood door

[markjg123]

I have made a small cupboard door (1600mm x 500mm) using 12mm exterior grade plywood and fixed 70mm x 18mm smooth planed timber to one face to give a Pattern 10 effect.

So far so good, however after about 48 hours (allowing wood glue to firmly bond) the door has bowed quite a lot.

I've trying bending the door back by placing in on supports and applying a heavy weight for about 48 hours. No joy.

The plywood was not cheap so I don't want to scrap what I've done.

Any tips to sort this?

 

[SimonH2]

I suspect the only way to fix it would be to steam it (to soften the wood), and fix it in a press while it's force dried. Even then there's no guarantee that ti won't change shape every time the humidity changes. Put another way, start again, and don't glue dissimilar woods together. You might consider making a frame with T&G joints in the corners, and fit play as panels within that frame - which is how panel doors are normally made.
There are many reasons the bulk furniture manufacturers use composites (eg chipboard and MDF) - this is one of them.

 

[ekmdgrf]

Put another way, start again, and don't glue dissimilar woods together.

Like a wooden version of the bimetalic strip. Maybe you could use it to turn the bathroom fan on and off?

 

[SimonH2]

Brilliant, if a bit slow acting

 

[markjg123]

I have no idea what ekmdgrf is talking about

 

[phatboy]

I have no idea what ekmdgrf is talking about

Different types of wood expand and contract at different rates as temperature or humidity change, so when they are glued together there will inevitably be some warping.

This is much like the switches used to turn on and off thermostats - 2 pieces of different metal bonded together, one expands faster than the other, making and breaking a contact as it does so.

 

[foxhole]

You should idealy ask advice before you start a project rather than ask for solutions to your failures.

 

[phatboy]

You should idealy ask advice before you start a project rather than ask for solutions to your failures.

Hindsight is a wonderful thing.....

 

[ekmdgrf]

Experience is the thing that you get just after you need it.

 

[Burnerman]

You actually needed another piece of ply to cover the timber.....just to balance the structure.
John

 

[gregers]

maybe you could try remaking it,but this time use just the ply.
with strips between the sandwich of the 2 pieces of ply.
then using some thin pine lip the door all the way round.