Just like the subject says. I finally got a torch set up using Propylene as the fuel. I am curious on how to make a smooth cut. I have cut some metal this weekend for my new between the frame rails winch mount. The plate I was using was 3/8" and 5/8" plate. I am using a #1 propylene tip that is rated @ 3/4" - 1" thick plate. The problem isn't the actual cutting, I made some good looking free handed cuts and some good "guided" straight cuts. The 3/8" and the 5/8" plate cut good except there were jagged edges. There was also something weird. There was a grove down the center of the 5/8" plate. This groove ran along the length of the plate and was about 1/32"-1/16" deep. What is causing the groove? And how can I keep from making the jagged edge?