RE: Foam cutting wire
Stranded wire I am told works I have tried it and don't care for it as it seems to be prone to buildup but any single strand stainless .020 to .030 works. If the wire is too small in diameter it’s harder to keep the tension on it so the wire stays straight while cutting without it breaking. Too thick and it takes too much current and is harder to get fine control. I use 1/4 piano wire as the ends of the bow and as the wire tensioner. Simple bows can be made by cutting a 36 inch piece of piano wire in half. On the end of each half grind a small groove 1/8 of an inch from one end. Use a length of wood dowel or square/rectangular stock and drill a hole in line at each end on a 15 to 20 degree outward facing slightly smaller than the 1/4 inch piano wire. Tap each piece of piano wire into the hole leaving the grooved end out. Wrap the wire and bind it by twisting the tag end around the main wire at one end. Pull the wire into the groove on the other end adding enough tension that the piano wire starts to straighten out then bind the second end. This will keep tension on the wire when it gets hot and also will take up any elongation of the wire which will help to keep your wire straight during the cut.
Dennis