I tried freehand oxy but the inner hole was too sloppy for my liking. I used large 50mm washers but they don't have the thickness I am looking for. I'm going to invest in a plasma cutter. Is it possible to use wooden templates for a plasma cutter? I can make them easily with a hole saw. Or would the plasma just burn the wood. I was thought how to weld, but notthing about cutting or drilling.