Carl Goldberg has the following in Big Print under Important Information : "Be sure to seal the edges down first so that you do not cause the covering to shrink and expose areas of wood." I always seal the edges first before removing any wrinkles and it has always worked for me. I have done this with Goldberg, SIG, H9, Great Planes and every other brand of ARF I've assembled. Try sealing the edges first and maybe even using your iron instead of your heat gun, that will give a much more controlled shrink. Also a heat gun will cook most decals so working around them with the iron is safer, touching them with an iron will melt them. Hope this helps. Best of luck.