Repainting Aluminum Siding
FIRST STEP: Check for chalk on the surface. Wipe the palm of your hand on the surface, if a powdery residue comes off on your hand there is chalk on the surface. This chalk has to be removed by washing the surface.
WASHING: Washing will do more than remove the chalk it will also remove dirt and mildew. Washing can be done more than one way. You can wash by hand from the bottom up or apply the soap solution with a garden sprayer and power wash from the bottom up. The soap solution should be made of 3 parts water and 1 part bleach and ad detergent. This solution should remain wet on the surface for 10 to 15 minutes. The best detergent would be JOMAX (follow label instructions for mixing ) other alternatives would be laundry detergent, dish detergent, Dirtex powdered soap or tsp (tri sodium phosphate). They will all work just fine but if you use tsp be careful not to make it too strong. Generally 2 tablespoons per gallon of water will do, if you make it stronger you may remove more than just the chalk. Another thing to remember about tsp is that it is a phosphate ( fertilizer ), it could inhibit the growth of weeds around your house. After washing the siding you must thoroughly rinse all the soap residue off.
PRIMING: Once all of the chalk residue has been removed, priming is not required. If any bare aluminum is exposed then use a 100% acrylic latex primer like XIM UMA primer, CALIFORNA PAINTS Frescoat latex primer or MAXUM 901Starter.
PAINTING: You should only use a 100% acrylic latex paint on your aluminum siding. CALIFORNIA PAINTS Frescoat 450-00 flat and 471-00 satin are our best and were ranked #1 two years in a row by consumers report. The reason we do not recommend an alkyd ( oil ) paint is because they fade & chalk in the sun. If you have primed your siding apply 1 or 2 finish coats of Frescoats acrylic latex house paint. Sometimes you can have your primer tinted to match your finish coat and eliminate a second coat of paint.