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 spray on Bloxide Aerosol 12 oz net wt. (16050Z) application. For longer term corrosion prevention use Zinc Rich, Cold Galvanizing Compound Aer (16006Z).