Talk to them. It's what I did. You can tell pretty much if they're worth their saltI have seen welders' ads on Facebook marketplace, but how do I judge which ones would be a good candidate to use.
Thanks Cody,I literally soak all the plastics for days in a bleach, dawn and bar keepers friend solution. They come out looking good, then plastic brush them and rinse in hot water. Get a scrub daddy. They do wonders