So today I noticed I had made some errors with the master so I edited it some. I vacuum formed and the master held up well, the only problem was that the plastic I have is not melting and stretching properly. I bought it about a year ago and it has a rough rigid side and a smooth one, I think the rough side causes the plastic to not melt properly and holds it together a little better, so I need to get some better plastic in the mean time.