i had my thermostat powder coated along with valve covers,intake and altenator housing. i had a small leak where the hard radiator pipe (jmb's) meets the thermostat housing. i did not have the thermostat housing clearcoated...and the hot water i guess has stained the powdercoating. what will remove this? anyone have any ideas, not sure if it will polish out.:dontknow: i'm thinking its mineral deposits?