The proper way to remove rail dust is to soak towels in “rail dust remover” and lay the towels on the offended areas of the vehicle. Follow the manufacturer’s recommended dwell time to allow the chemical to dissolve the rust spots and loosen the particles of metal.
When this is accomplished rinse off the car with high pressure water to insure all particles are gone.
Then pre-spray the car with a mild alkaline cleaner to neutralize the acidic rail dust remover. If you do not do this, acid will remain on the paint finish and when it gets wet it will be active and could etch into the finish.
Then rinse off the alkaline chemical and follow that with a thorough hand car wash using a mild carwash shampoo and water.
To be safe, a coat of wax or paint sealant should be applied to the paint for protection.
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