To prepare a metal surface you will need to remove all flaking paint and rust. The easiest ways of doing this is by using a scraper, wire brush and/or sandpaper.
Once again it is vital to make sure that whatever surface you are going to paint onto is sound and doesn’t have an adhesion problem. Go and check our
Adhesion Test Page if you are not sure.
If the surface is in good condition it may just require a light hand sand to assist the fresh paint to adhere to it.
If unsure of the integrity of the surface it can sometimes be easier to use a small grinder with a medium to fine sanding disc, and running over the entire surface. Once that is done you can then concentrate on grinding back any areas that have rust.
Once back to a sound base you can now think about painting.
We recommend that on metal areas use oil primers and undercoats. The use of water based or acrylic paints can promote rust.