How to Paint a Galvanized Downspout

You can successfully paint galvanized downspouts with proper surface preparation.. Remove any surface contaminants on the downspout through a combination of brushing and liquid cleaners. Use only paints and primers specifically formulated for galvanized metal products.

If galvanized material is not properly prepared and cleaned before painting, the paint will not form a proper bond with the material. The result will be cracking and peeling of the paint from the downspout in a short time.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Water-soluble cleaning agent
• Stiff-bristle brush
• Wire brush
• Galvanized metal primer
• Outdoor metal paint (compatible with primer)

1. Scrub the downspout with a water-based cleaning agent and a stiff-bristle brush. This will remove the protective coating of oil that is often present on galvanized metal. Rinse thoroughly.
   
   Do not use oil- based cleaners, such as mineral spirits, as the oil can prevent the paint from adhering.

2. Remove any corrosion from the downspout with a wire brush. Corrosion on galvanized metal is known as white rust (zinc carbonate) and will prevent the paint from adhering.
   
   Do not brush so heavily that the zinc coating is removed.

3. Apply a coat of a primer recommended for galvanized metal. Normal metal primers do not adhere well to zinc. Primers are available in spray cans or as liquid, and should be applied as soon as possible after cleaning the downspout.
   
   Allow the primer to dry completely. Use multiple coats if directed to do so by the manufacturer.

4. Apply a coat of finish color paint over the top of the primer. Choose a paint with is compatible with the primer used.
   
   Use multiple coats if directed to do so by the manufacturer.

Tips & Warnings

• Wear respiratory protection when sanding any galvanized material.

References

• Painting Galvanized Metal
• White rust

Resources

• Water-Based Cleaner