[Blue60]

I applied two coats of sprayed POR15 on brake drums (external) during renovation approx two years ago. Currently replacing leaking cylinder. After beating on the drum with a 5 lb baby sledge and a block of wood to remove the drum, there was no evidence of chipping or damage to POR15 coating. They were prepped simply by sandblasting prior to application. Same with my hood hooks - POR15 after blasting, then two coats of Pewter. Pewter has come off hooks where they "hook" to the apron catches, but the underlying POR15 has not. Verdict - I like the stuff.