yes I have welded different kinds of plastics since in HS 1976. I have a 2 yr industrial plastics degree also. almost bought a plastic welder back then, 1976 they were like 600 bucks. they work great, as long as you are matched up with what you are welding. also some mold sprays will melt polystyrene, abs, pvc, polyethylene, polypropylene, pet, abs, the plastic they use to make model cars from, poly styrene, and you can make your own glue from all of it. also, it melts the styrene. we used to use it to get stuck undercuts out of dies.
what I found works excellent is one of the old, old, ol, long,long soldering irons. I fixed MANY push mower tanks a AND resold after welding them with poly pro, and poly ethylene MILK JUGS and pop bottles. you can tell the smell after 30 years of working in it all. and pet I light it, take a whiff, and know exactly what I got to work with.
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