I cant seem to stop my water pump housing from seeping. I've welded all over it changing it to what I need, and I keep getting a seep. I've re welded it once and just made the seepage move to a different location.I mean a seep that will only leak with 20 lbs of pressure and after it cools some. It will produce 5 or six drops in an hour. Is there some kind of coating I an put inside it to prevent this?