Almost all to the whole surface area with the wrought metal. Made-for-metal primers also come in water the form and find them www.taiwan-aikido.org/modules.php?name=F...ile=viewtopic&p=8818 with a lot of equipment merchants. A better choice can be an aerosol primer as it offers you better coverage especially if your current wall features complicated scroll perform designed in the layout. Allow the primer for you to dried per producer guidelines. Almost all primers will need 1 in order to 3 time of blow drying moment. In the event the primer is usually dried out you may apply.