How should I prep old aluminum siding before painting? What type of primer is the best for siding?
A. Remove as much “chalk”, dirt and mildew as you can. This is done by power washing or by scrubbing and rinsing. The only times a primer would be needed are: 1) If any bare aluminum is exposed; then use a latex corrosion-inhibitive primer; 2) If there is still “chalk” left on the surface, apply a quality exterior alkyd, oil-based primer recommended for aluminum siding by the manufacturer.