Material Warping

[BrandonB]

Hi all,

My question is how do you prevent material from warping. It's something we all have to deal with no matter how you stack,store or sort your material it's always the last piece or the one section that you need to be pretty straight that ends up bowing.

I thought I would ask this forum as I've recently had two installs where the doors have bowed in the middle and it is frustrating. I can't understand what is causing them to bow or how to prevent or repair it. I build alot of wardrobes/cabinets usually MRMDF/Birch plywood and I find the doors often bow in the middle when I come to hang them. I noticed it on a install where the doors are around W 330mm x L 1000mm x 18mm Birch plywood machine cut by my supplier and oiled before installing. Stacked upright against a wall as straight as I can or stacked with spacing timbers between to allow the moisture to circulate around the doors. They are never lent up or put on their side. Even if I were to use thicker material what's to say they won't do the same thing?

Do you think it's moisture from where I make them/prep them, to bringing them into a clients home?

Any advice or experience with this would be a massive help.

Thanks,
Brandon.

 

[doctor Bob]

Not even big doors. Very odd.

 

[MARK.B.]

Brandon have you applied the oil to both faces

 

[BrandonB]

Brandon have you applied the oil to both faces

Yes, both oiled at the same time with an even amount.

 

[MARK.B.]

Ahh pipper it , there goes my theory

 

[Doug71]

I do sometimes wonder if cabinet doors bend because the outside of the door is in a heated room and the inside is a dead space within a cupboard with slightly different conditions?

Do the doors bend inwards in the middle?

 

[BrandonB]

I do sometimes wonder if cabinet doors bend because the outside of the door is in a heated room and the inside is a dead space within a cupboard with slightly different conditions?

Do the doors bend inwards in the middle?

It's tricky to say but I would say they normally bend in the middle usually the same way sometimes one in and one out so it looks rubbish when closed. It's annoying even if you went above and beyond and made them using poplar/22mm MRMDF they would still bend. Everything is cut by machine and stored correctly, I prep the panels for the install by either priming or oiling them prior to installing. It's all done on the same day evenly and stored correctly and when I come to install the finished product it's bent and I can't really do much about it. If you had to replace it, you may get the same result?

I have clamped a straight edge to it over night before and it did help but not ideal in a clients home.

 

[MARK.B.]

OK here here goes with theory number 2 When you say they are spaced to allow the moisture to circulate Did you mean Air or is your workshop damp

 

[BrandonB]

OK here here goes with theory number 2 When you say they are spaced to allow the moisture to circulate Did you mean Air or is your workshop damp

I mean't air, my space isn't great for mositure I must admit.

 

[MARK.B.]

Damp workshop not ideal to be be fair for your timber or tools . How long is the ply in the shop before oiling them ? if its any length of time the nice dry ply might get enough moisture in it to cause you problems

 

[Distinterior]

What are the storage conditions like at your suppliers..? The ply could well have a high MC before it's even delivered to you!

 

[BrandonB]

It may be because I stored it in my shipping container before installing.

 

[MARK.B.]

Were you're other door materials also kept in a container for any length of time ?

 

[BrandonB]

If I remember correctly, they were stored in there before I made up the doors in a different space. I guess a shipping container is a massive sweaty metal tin with no ventilation. It may explain why it's becoming such a problem.

 

[MARK.B.]

Could well be a major part of the problem. Is it your container or hired ?, if yes you could modify it for better storage conditions .
The temperature changes can go from one extreme to the other quite quickly given the right weather conditions.

 

[baldkev]

Or if you have power, a dehumidifier. Dessicant type.

I have had to insulate the ceiling of mine, which has cut out the issues ( i already used a dehumidifier )

 

[planesleuth]

It's just common sense. The problem is everything and the problem is nothing. Air pressure, high pressure, low pressure, moisture at 7.5, moisture at 25; on and on. Don't store anything in containers. Cut your own boards/timber and then you can control the quality. Choose a quality stable board from a good supplier. Find out how the boards are made. Where they are made, How they are stored. 21st century MDFMR and Birch Plywood are just about the worse for bowing. Don't rush, be in control of the whole process. Make no door less than 22mm thick. Avoid all skinny sizes. 1000mm x 330mm? Can't you design it differently? Don't leave anything 'stacked upright' against a wall. If you have to store them then it's always flat, dead flat, level, horizontal, off the spirit level, then it's belly to belly, scoop to scoop, no sticks in between, then clamp them all together. Your boards and timber have to have pretty much the same stable moisture content throughout the process, so does your store room, workshop and bays and that moisture content has to be about the same as the client's house. All these conditions/rules can be followed; if you won't or don't then you should leave the business.

 

[Droogs]

You're keeping the stock in a too wet (humid) location and it is drying out too fast once it is in situ with central heating by the sound of it. Maybe need to look at dryer storage more similar to the conditions found in housing these days

 

[OldWood]

I'm not too sure of this claim, but I have been in the Sahara Desert and I've been in over warm houses and strange though it may be but the claim is that such houses are actually at a lower RH than a desert. In order to get your product to remain in the manner wanted you may not quite achieve this but you have to get near it.
Rob

 

[Brian Charles]

Hi all,

My question is how do you prevent material from warping. It's something we all have to deal with no matter how you stack,store or sort your material it's always the last piece or the one section that you need to be pretty straight that ends up bowing.

I thought I would ask this forum as I've recently had two installs where the doors have bowed in the middle and it is frustrating. I can't understand what is causing them to bow or how to prevent or repair it. I build alot of wardrobes/cabinets usually MRMDF/Birch plywood and I find the doors often bow in the middle when I come to hang them. I noticed it on a install where the doors are around W 330mm x L 1000mm x 18mm Birch plywood machine cut by my supplier and oiled before installing. Stacked upright against a wall as straight as I can or stacked with spacing timbers between to allow the moisture to circulate around the doors. They are never lent up or put on their side. Even if I were to use thicker material what's to say they won't do the same thing?

Do you think it's moisture from where I make them/prep them, to bringing them into a clients home?

Any advice or experience with this would be a massive help.

Thanks,
Brandon.

I also had the same issue with sandwich core m/r Mdf ..it was with 22mm thick boards some of them bowed and what ever I did it still went back to its bowed shape I even wet it and I mean soaked them and clamped them but it always seemed to go back to its bowed shape I did contact the suppliers who Said they ever never had anyone have this problem and I should have took it back but I did order 10 boards along with 10 18mm boards and they where perfect ..