Red Oxide High Build Synthetic Primer 5 Litres. From Alpha Coatings this is a Red Oxide Synthetic Primer in a 5 litre tin. It is a high quality air drying metal primer incorporating above average anticorrosive properties along with excellent opacity on a modified alkyd base. This product is recommended or use on structural steelwork, fencing, machinery, trailers, containers, components, agricultural plant & equipment etc on it's own or prior to the application of one of our industrial topcoats. Supplied in a 5 litre tin.