Do you have a problem getting air inside the bag after sealing while you are shrink wrapping with the heat gun? I bought the 3" tubing and sealed one end, dropped in my tart and sealed it again. As I was hitting it with the heat gun, it was blowing up like a balloon then got a tiny hole in it then it released. I also can't get it shrunk without it melting a little on the edges. Is there any hints someone can share? I would greatly appreciate it! Kristy