Salt needs to be removed from the surface prior to any cleaning blast or mechanical cleaning of salty surface will push the salt into the steels surface.
Next degrease with a degeaser that does not leave an oily surface, all of Rustbusters degreasers are suitable for this purpose, any grease left on the surface can be blast or mechanically pushed deeper into the steels surface if not removed prior to rust removal.
So even if you think the steel is clean wash it with fresh water and a detergent solution like Rustbuster SP10 or Rustbuster Safer Degreaser for those that want to avoid caustics. Do not use white spirit, turps diesel or paraffin to degrease prior to painting, this will only remove the surface grease and leave an oily diluted residue within the steels pours, this will lead to system failure
1. Remove any loose paint and rust back to sound clean metal with DA or flap wheel 2. Treat steel with Rustbuster Phos-Kleen B panel wipe 3. Prime with Rustbuster Custom Epoxy 421 4. Fill and prepare defects Dinitrol 6030 metal loaded filler 5. Further coat of Rustbuster Custom Epoxy 421 6. Finish with body paint of choice
prior to painting by wiping the surface with Rustbuster Phos-Kleen B solution, this will passivate the steels surface and turn any iron oxide within the steels pours into iron phosphate. The surface will turn a blue/black to indicate it is ready to paint. Just prior to painting wipe the treated surface with Chlor-X to remove any phosphate salts and DA sand or hand sand with an 80 grit abrasive this will leave the surface profile of the steel ready to take the primer
Prior to applying paint to Phos-Kleen B neutralise and remove any phosphate salts by washing down with Rustbuster Chlor-X DTS salt remover prior to priming