Hey guys im pretty new to this forum but I've been working on cars for a while with my dad, I'm 16. Anyway I don't know if anyone has heard of this but I use something called rondo. Its a combination of bondo and resin. Anyway I use 70% Bondo and 30% Resin. For hardener you can use the cream that came with the Bondo or the MEKP Resin hardener. I find it to be harder than bondo when dry, easier to sand, and gives me about 45 seconds more of application time. Let me know if any of you guys try it. Thanks, Nick