If it's only slight surface rust, we wirebrush or sand then apply a metal primer (usually Kem Kromik from SW) then a finish coat.
For very heavily rusted surfaces, we've used Ospho, sold in quarts at a local paint store, then coat with metal primer and finish coat.
For very heavily rusted surfaces, we've used Ospho, sold in quarts at a local paint store, then coat with metal primer and finish coat.
