Cracked my fender by riding the wall up a nasty hill at Hatfield McCoy this past weekend. I have a plastic welder and four different types of filler rods, but I’m not sure which one to use. The rods I have are ABS, PVC, polypropylene, and some mystery material that came with the set. I’m planning to press metal mesh into the plastic on the underside of the fender to help add strength. Which type of welding rod will best stick to the plastic fender?