Don't want to start a fuss, but I never use a heat gun when covering. You cannot regulate the temperature with a heat gun. Use an iron, and get a good thermometer made for setting the iron temp, and follow Solartex's instructions on heat settings.

And what Campy said about clearcoat. I love Solartex, but the finish isn't as glossy as I'd like on some planes, and the clearcoat fixes that, in addition to making it easier to keep clean. Also, if you want to paint any areas, latex paint works great with Solartex, but it does require the protection of a clearcoat.