Anyone have any tips for flattening depron sheets? All the control surfaces from a model I'm working on(index 2.2) are bowed slightly, and even after a week of sitting with some weight on them, they're still bowed when I take the weight off. Its not extreme, but its definitely noticeable and too much to forget about(about a 1-2mm gap in the center of an aileron if sitting on a flat surface).

Good question, I could use with an answer myself

Put weights across the bowed parts on a flat surface and use a hairdryer to heat up the depron.

I just put it under weights for a few days before I build them. Stack books and magazines on top of everything.

I have found after a while that the control surfaces on my a couple of my planes have warped slightly, especially those control surfaces with counter balance design.

One way I rectified this was to slightly stretch and apply a short strip of hinge tape on the opposite side of the control surface. Care must be taken as, if the hinge tape is stretched too tight you can induce a warp in the opposite direction.

Cheers,

Jeff

^^ excellent idea! I'll try the hairdryer first to keep weight down, but if that fails I'll definitely go with the tape.

Of course try this on a scrap piece of depron 1st to make sure your settings are right, but I use my heating iron. Real low settings and quick application of the iron to foam and treat it just like covering. Apply heat to opposite side of warp and overbend it in the direction you want to correct. During cooling let it set on a flat surface(ruler, block, table, etc) Works quickly after you've already constructed model and is a good quick fix in the field if you show up and realize your plane is warped when your're just about ready to fly! My 2 cents

Happy New Year!!

Jason

Iron it like a pair of pants with Aluminium foil between on flat surface like glass. Those other remedies did not work for me and were huge pain anyway.

I also use glass or an aluminum flat bar to cool my parts on(usually ailerons) and it acts like a heat sink cooling the part rapidly and straight. Ditto!

Roll and curve the depron betwwen your Thumb and forefinger.
Takes a couple of minutes. No need to use weight and irons.
Do it before assembly and after as needed.
Mike Hammel told me this and it works .
Marc

Tries this too and it weakens the foam big time.

Originally Posted by marcwv

Roll and curve the depron betwwen your Thumb and forefinger.
Takes a couple of minutes. No need to use weight and irons.
Do it before assembly and after as needed.
Mike Hammel told me this and it works .
Marc

Originally Posted by wparsons

Anyone have any tips for flattening depron sheets? All the control surfaces from a model I'm working on(index 2.2) are bowed slightly, and even after a week of sitting with some weight on them, they're still bowed when I take the weight off. Its not extreme, but its definitely noticeable and too much to forget about(about a 1-2mm gap in the center of an aileron if sitting on a flat surface).

Lay the part flat on a table. Lay a damp towel over the part. Use a clothes iron lightly on the towel to "steam" the part flat. It will take some playing around, but Depron will take a heat set and the part should lay flat.

Mike Hammel
fancyfoam