How to Paint Galvanized Metal. Galvanized metal is metal that's been dipped in hot zinc to protect it from the weather. Unfortunately, paint doesn't always adhere so well to zinc.
Lay down a thick layer of newspaper below the area to be painted. If you're working over grass, you'll want to protect your lawn from chemicals that might kill it.
Use fine wet/dry sandpaper dipped in mineral spirits and lightly sand the entire surface that is to be painted.
Allow the metal to dry.
Apply a primer designed specifically for galvanized surfaces. Check the manufacturer's recommendations - some suggest two coats with a sanding session in between.
Be sure to choose a paint that will hold up to the weather (see Related Hunkers).
Apply the paint with a sprayer for the most uniform coverage.