Cleaning Aluminum Window Screen Frames

This is an answer to the same question I wrote some time ago. Hope it helps.
Years ago aluminum storms were not anodized causing them to oxidize when put to the weather. This is the same as steel rusting. Later aluminum storms were anodized by electrochemical method to stop the oxidizing. So some anodized aluminum storms are natural (silver color) or have a color. You could clean them with TSP (trisodium phosphate) and a stiff brush.

You should be able to buy TSP in a hardware store. Spic and Span used to contain TSP but I don't know if that is true today. When finished with the soap, water and brush the old aluminum storms may still look tired and old. That is the nature of old un-anodized aluminum.