Quote Originally Posted by chevynut View Post
I ran into a problem that's driving me nuts and I can't figure out what's going on. I'm trying to polish my PRC radiator so I can install it into my radiator support. I cannot get it to polish for some reason.

I just spent weeks polishing all my stainless exhaust, gas tank, plumbing, and a whole bunch of suspension parts with no problem using the same equipment and materials. I took the radiator out of the box it's been sitting in for years, sanded it with 1200 grit to get it smooth. Then I tried to polish it with my die grinder with a cotton wheel on it and thought it might take me an hour or so to finish it. The problem is that the buffing compound just builds up on the radiator, and it won't polish it. I did some research on the problem and it suggested the part was too cold causing the wax-based compound to freeze on it so I heated it with a propane torch. It did the same thing. I tried 3 different compounds (brown white, green) and they all do the same thing. I even took the radiator to my buffer and tried 2 different wheels and 3 different compounds and no go. I tried polishing another aluminum part and it works fine.

What the hell is going on? I spent 3 hours trying to get this to buff and I've gotten virtually nowhere. All that happens is the radiator turns black from the compound and a film of compound builds up preventing any cutting. I don't know what kind of aluminum they use for the radiator frames, but it shouldn't really matter.
When I was QAM at the Kirby Vacuum Cleaner Company, all of the Gen III was polished to a high luster. They never sanded by hand but rather used a belt of an unknown grit (they treated it first). The compound, was black. It would take less than 2 minutes for any one part to be polished. They did use a compound rake to remove the excess from the wheels. I'll try to contact a friend there to see what exact compound, grit and wheel material they used if he is still there.