I need to rustproof some inner body cavaties on a 71 Chev pickup. I have welded in new door piller bottoms and cab supports after painting the inside of the patch panels with cold galvanizing compound (great product-dosent burn off from welding heat) but I am concerned about the welds themselves. I also replaced the rockers & backs again after treating the inside with cold galvanizing compound. How would you suggest that I treat the welds inside the closed sections to prevent them from rusting? thanks bob