Can I paint a galvanized chimney?

No problem. Let it weather for a few months first, or pickle it with vinegar or other etchant. Apply a metal primer before using an oil-based or vinyl latex paint.

FWIW We have regularly painted the galvanized conduit, the meter box, into which the glass topped meter plugs, the few feet of conduit below it, which happened to be non galvanized, (although nobody noticed it)! and the goose neck below that which turns and goes into the basement etc. i.e. the metal piping which contains our AC electrical service. We have used the same oil based 'stain', not paint, as our 10 inch pine siding; probably painted it four or five times in some 30+ years. So it's same colour as the house. Looks fine and doesn't rust in our corrosive one kilometre from the North Atlantic conditions! Only thing though; does your galvanized pipe get hot? If so that's different!

Is it double layer pipe, how hot does it get. Get an IR thermometer from Radioshack. Paints have temp limits, Black stove paint can be used, you can also get other high temp paints for motors at auto stores. But true Stove paint is only in a few colors. I have an automotive paint from Duplicolor that says 1200 f , My black stove paint says 1000 f. You must clean off the oils real good with strong soap, talk to a paint store on cleaning.

Wait until next year for the zinc to oxidize and passivate. Then you can paint it. Of course, after it oxidizes it will be gray on its own, you might not need to paint it.

Bob

My local hardware sells primer for aluminum, zinc, and galvanized metal. Just clean the surface with 409 or fantastic, dry, swipe with thinner-wetted rag, and dry off. Then prime with the specialty primer. Better see how hot the outer chimney gets, first, though - may need special paint for hot surfaces....