First let me say that I have no experience with paints in cold climates/freezing conditions. If that applies to your situation, you'll need other's input. But here in California I have done more than 200 aluminum siding repaint jobs over the past 15 yrs, and have tried every brand of paint that I'm aware of. One product stands out, and that is the top grade Sears Weatherbeater satin(black can). It does an outstanding job for this specific purpose. And no, this isn't a plug due to the Sears connection. In fact I don't use any other Sears paint product for any purpose. Wash down the oxidation well, and apply 2 coats. No matter what they say, there isn't a paint on the market that can provide first rate looks and durability with one coat. Scraping, sanding, wire brushing of loose, flaking paint is pretty straightforward. Don't need to spot prime.