You got to seal it or the rust will come back.
How to repair pitted sheet metal.
Sand the area with a coarse grit sand paper using a circular motion.
Attach the wire brush to the drill and apply to the metal.
Grind down heavily rusted metal spots faster with a wire wheel and a drill or angle grinder.
You can use a.
In order to properly treat fill and prep the fender just follow these easy steps.
The sand paper can be held in your hand for smaller.
How to fix pitting in metal before painting clean.
Moved over to the passing lane.
Using a filling primer would probably result in still being able to see the pits to a certain extent.
Sand the area again with a fine grit sand paper to.
The electrolytic bath gets things cleanest a chem rust converter is a good idea to insure it s clean then filler is the only way to get it smooth sand blasting is good but even that will sometimes leave oxide in deep pits so the converter is still useful.
Power brush the rusted areas with the wire brush on the power drill to remove the loose rust and flakes from the sheet.
Apply eastwood fast etch to the area with the rust pits.
Give it a serious cleaning mayhaps some naval jelly or some other type of rust remover.
Work on the worst affected areas first removing as much of the rust and flaking metal as possible.
Cover the area with plastic wrap to prevent the fast etch from evaporating before it can work.
Assuming that your metal is still strong enough i would use a polyester sot putty which is basically a very fine grained body filler that is slightly easier to sand.
Work outward and then return as you remove the pitting from the metal.
If the area is heavily rusted and pitted and wire brushing by hand is ineffective use a drill with a wire wheel photo 2 and a primer that adheres to rusted surfaces such as krylon rust tough or rust oleum.
Then paint it with fiberglass resin like you use to glass stuff only without the cloth then give it a skim coat of mud or bondo or whatever they call it where you are from.