Bent MDF

[the_g_ster]

Hello All

Whilst standing back and looking at the top of my new built in wardrobe and admiring the fact that all the top and gaps aligned perfectly I then looked down to see that one of the 4 doors bows out at the bottom.

So adjusted the hinges, checked the mountings and all staight and true. Found a long stright edge and I have a banana door.

Tried bracing the back of the door to pull it back and no luck, so not really sure what to do now, any ideas?

G

 

[newt]

Have put any finish on the doors if so should be the same amount each side.

 

[LarryS.]

have you tried kicking it ?

 

[the_g_ster]

6 coats on front, none yet on back.

 

[WellsWood]

Sounds like what you want is the Planofit door straightening system. It's basically a rod let into a shallow groove in the back of the door which can be adjusted into tension or compression to adjust the bow. Hafele do it but links don't work so I can't post one - just go to hafele.co.uk and search for planofit or item code 406.99.100

They're not expensive, about £20+vat per pair (they recommend you use 2 per door, but if you've got a sensible number of hinges on you'll probably get away with 1), but you won't be able to get them from Hafele without a trade account and their insufferable minimum order value scenario. If you ring them and ask nicely they should point you to somewhere that will sell to you retail.

 

[BradNaylor]

Mark's description of the Planofit intrigued me and I found it on the US Hafele site. Scroll down to page 446

http://www.hafele.com/us/external/catal ... 40-448.pdf

Cheers
Dan

 

[orangetlh]

The problem you have is the front of the doors have been sealed with the six coats but the backs are unsealed and can take on or loose moisture. This will make the MDF bow or cup almost as much as veneering one side and not balancing it. It is important to seal the backs as quick as possible to stop them all from moving. As for the one that is twisted, finising the back may help to pull it back flat but i doubt it. I have never seen the above mechanisms but they look pretty ugly to be puting on the back of a nicely made door, It might be a case of starting again with thatdoor im afraid.

 

[rjb]

I've experienced this problem with MDF and it is due to one side being sealed and the other side absorbing moisture and swelling causing the bow. If the panels are currently in a damp workshop I would move them into a warm dry environment for a while as I think this should reduce the bow at least partially. If that works I'd then seal the back of the panels to prevent them getting any worse.

Richard.

 

[newt]

Trouble with MDF in my limited experience is that it does not behave like wood. If it swells due to moisture it does not go back to its original dimension when dry. If it gets bent due to a load you can bend it the other way by reversing the load. I understand that MDF cannot support its own weight without some deflection, the deflection I assume is a function of the span, eg the length of a shelf. However it is a very useful material in certain applications.

 

[chippy1970]

You should always seal all sides soon as possible to avoid this problem same as when you veneer you should also use a backing veneer on the other side to keep things equal.

Bit late now but at least you know now for next time but maybe with the right hardware you can pull it back as suggested by the others.