How to Repair Thermoset Polyurethane

Thermoset polyurethane was commonly used on domestic bumpers back in the 1980’s and 90’s. It’s pretty much been replaced by polypropylene now, but you’ll still see the old yellow plastic out there once in a while. Polyvance was formed in 1981 as Urethane Supply Company to address the needs of bumper recyclers and to supply products to repair urethane bumper covers. Around that time, many people did not think urethane bumpers could be repaired. We proved they can be repaired. Polyurethane is a thermoset plastic, meaning that it is NOT meltable. The solid is formed by reacting two liquid components which crosslink in the mold. You will NOT be able to use the nitrogen welder on this type of plastic. You can repair it with the airless plastic welder. This will not provide a fusion weld. The urethane welding rod is used more like a hot melt glue. Welding on the back: 1:55 Welding on the front: 3:38 Flex test: 4:20 Applying filler: 5:01 Look below for links to some of the products from the video. View this vid