Exterior Painting Preparation
How do I properly prepare the surface before painting vinyl or aluminum siding?
Vinyl or Aluminium Siding
Clean the surface thoroughly with a pressure washer or with a cloth and a solution of water and trisodium phosphate (TSP). TSP is a degreaser that is used to wash surfaces prior to painting or staining. It can be purchased at MF Paints distributors.
If there is any chalking (presence of powder) on the aluminum, you will need to brush it away with an acid solution such as pure vinegar, or a solution of 10% hydrochloric acid in water (always pour the acid into the water and not vice-versa), or a metal cleaner. Rinse.