Don't worry about killing your machine, I was terrified of killing mine (with 2mm neoprene) and I was using Lube to line my needle but the machine would go really slow! So when I was sewing my side seam with the vinyl between the 2 sheets, I didn't use lube and it went through the machine like butter! It was amazing! I still went slowly because I dust want to break my needle or anything but I didn't even have to worry.