Hey Sherm
The Heat Gun is a must have tool on my bench. With NEW Arfs I like to set them out on a nice warm day, or bring them in by the register in the house, and let the Covering get pretty relaxed. Then go over the whole Plane with a Heat Gun which helps you get an even maximum amount of shrinkage over the whole Plane. Usually after you do this once you won't have to much trouble with bad wrinkles during those hot days of summer. If the Plane is covered in Monokote or UltraKote you can get the covering pretty warm with the Gun, but some thinner mil lower temp coverings such as EconoKote or TowerKote will burn easy, so you may want to start out in an inconspicuous spot to adjust the heat for your type covering. For small Bubbles, a needle, and an iron with a Hot Sock work fine, but I personally prefer just using the Heat Gun and a hand with a soft cotton glove on it.