Nope- I'm not mixed up. My trailer is made from extruded "galvanized"
aluminum I-beam. Aluminum is very susceptible to galvanic corrosion. You are
partly right though. Iron/steel is traditionally galvanized (zinc treated)
and aluminum anodized.
Recently, aluminum manufacturers found they could produce a galvanized
aluminum product that was more cost effective, equally, if not more, durable
and had a more polished or finished look that was perfect for outdoor use
and required very little care/maintenance. But don't believe what I
say....do a search on "galvanized aluminum" and you'll find numerous uses in
industries from aircraft manufacture, to outdoor lighting, to food container
coatings, and yes....even boat trailers.

B