Bloxide - The preferred weld-through primer. This Aluminized de-oxidizing primer insures x-ray quality welds. Promotes the formation of Aluminum oxide at the weld site to reduce porosity. Prevents corrosion of coated steel surfaces for several months of outside storage. Easy brush or spray-on (no thinning required) application Bloxide Qt. (16055ZP)application. For longer-term corrosion prevention use Zinc Rich, Cold Galvanizing Compound Qt (16005ZP).