Painting Galvanized Steel Siding

I'm looking at putting an extension on my horse barn this summer. The existing barn has steel siding with a factory finish colour. I have access to a bunch of used siding that matches the profile but has a plain galvanized finish. I've done some online research on painting galvanized metal but I'm getting some conflicting advice (imagine that on the internet). I therefore have come to the hive brain of GRM. This will be a 24'x40' extension so i need a prep and paint method that can be used on large surfaces.

In reply to Wayslow:

Go to your local Sherwin Williams store. They will be able to give you the correct info and products.

The short answer is latex.

The longer answer is that galvanized is REALLY tricky to paint, but latex usually sticks pretty well. It can vary from metal to metal and brand to brand of the latex. I'd recommend trying a few types on a test piece and going with what works best.

jg