size of panels & warping

[zarina]

I have a panel 150cmx x 100cms. Any bright ideas about what size thickness MDF I should use. I normally go for 9mm width but I am worried about the eventual weight of the painting, so I am considering 6mm instead. My concern is 6mm is more likely to warp. With panels this size, is it best to cradle, or just apply equal coats of gesso on both sides to help reduce warping. Any advice would be v helpful. I do glaze my works, so weight is an issue here! Does anyone out there paint this size using MDF? What widths do you use, & any tips to reduce potential warping? Any suggestions would be very helpful - thanks

[turlogh]

I haven't used MDF at that size. If it were me, I'd use masonite or birch plywood. If you want to use MDF, I would suggest the thicker kind to help resist warping (even though it will be heavier) and for strength. I generally apply multiple layers of hide glue on the back rather than gesso, since it's easier to work with, doesn't crack, and appears to work just as well.

I don't apply bracing to the back of my paintings, since I worry about various problems that can cause. I don't have the carpentry skills to make a real cradle with sliding dovetail joints, so I work very hard to make sure the glue on the back and the gesso on the front balance each other out.

Good luck.

[zarina]

If I use birch plywood for a panel of this size, & take care with applying hide glue on the reverse, as you suggest, this should be OK? No need for battoning etc? Doesn't MDF warp less than plywood? I may just try a thicker MDF & hope it isn't too heavy!

Thanks for advice

[Dennis H]

Zarina,
I'm hoping Rob Milliken will respond. He uses MDF in about that size and should have good advice for you. I know he's busy with a project just now and is therefore not often at the computer. If you don't see a posting from Rob soon, shoot him a private email.
Dennis

[zarina]

Dennis
Thanks - I will keep a look out. Zarina

[Dimitris C. Milionis]

any progress on the issue above, does a 6mm MDF warp at 100x150cm