Im having trouble keeping my rudder and elevator flat after I cover them. They keep warping. My dad told me to keep heating on both sides till they straighten out, but they dont. I cut the covering off and am going to try again tomorrow. Im using econokote covering. Is there any way I can keep this from happening? Or is there another way to fix it?

What type of material are you covering ? balsa, foam, fiberglass it sure would help to know. Econokote is for foam I think.

Econokote is not specifically for foam but works well with some foams

You can use it on balsa also

Use a better covering (Ultracote or Monokote). Cover one side and do not shrink it. Cover the second side and, with your iron at a low setting, shrink part of it. Then flip sides and shrink the facing part. Work one side and then the other until all is shrunk. Do not use the highest heat settings.

Sorry, im covering balsa. I'll try that thanks!

Econokote has less shrinking power than Monokote but is about the same as Ultracote

when it shrinks it pulls the corner on the opposite side and warps. is there an easy way to fix this if it happens again?

i think you need to shrink less at a time. i had a prob with my elevator warping and i just held it straight which caused one side to sag...then just heat that part sagging and it held it straight again.

Make sure that after you heat the covering you weight down the tail, etc. on a flat surface ( I use heavy weights ) and let it cool.

Flip it over and rinse lather and repeat to help straighten things out again.