I have a very nice SIG Waco SRE. I am having similar problems making small repairs. Patching a small puncture hole or whatever and the SIG covering is miserable and almost impossible to get perfect. I am used to Ultracote and have no problems with that. It seems that the problem starts after sticking the SIG Aerocote down. When I shrink, the original edges pull in. You can see the glue beyond the original patch edge. Of course that makes it impossible to remove the wrinkles. Maybe I am using a little too much heat. I have yet to achieve wrinkle free results, but I will kep trying. The airplane 's original covering is SIG Cub Yellow so I need to keep the color match. The roll I bought doesn't match perfectly either. I suppose all covering colors vary with different batches. [&o]