Mastercoat Metal Prep is out of stock, can I use a different brand metal prep?

Yes. Metal prep is a very good step to take but not necessary in every application. It is highly recommended to use to dissolve surface rust, etch the surface, and ensure a toothy surface for adhesion for our permanent rust sealer. However the rust sealer will still adhere to surfaces that have been cleaned of oil and grease (use mineral spirits), and loose scale removed. If our metal prep is unavailable, other brands of metal prep can be used. We recommend phosphoric acid, preferably with zinc as an ingredient. Follow instructions of your brand and make sure the surface is thoroughly dried before applying Mastercoat rust sealer.