How to Paint Galvanized Sheet Metal, Gutters, or Valley Tin

How do I go about priming and painting galvanized valleys and flashing on my roof? -Abbey

Hi Abbey,

If galvanized metal is not prepared and painted properly, it will tend to peel over time. Clean new galvanized metal surfaces with a water based cleaner/degreaser to remove any oil or and contaminants. Once the metal has dried, dampen a cloth with white vinegar and wipe the surface down. The acid in the vinegar will act to etch the metal and help the paint adhere.

On older galvanized metal surfaces where the zinc coating has begun breaking down (known as white rust), use a wire brush or fine sandpaper to remove the chalky film before cleaning it.

Once the metal has been cleaned and is dry, prime it using an exterior multipurpose latex primer, or a latex primer that is made specifically for galvanized metal. Topcoat with two coars of a high quality exterior latex paint.

Good luck with your project,



  1. I obtained and retrieved from my bulk storage barn, a galvinized mailbox. It has been painted with what appears to be (white)latex paint. It is pealing worse than a 2nd degree sunburn.

    Because its metal, I want to use it, and the door broke of the existing plastic mailbox.

    I know the metal has to be cleaned, but would soda blasting be the best way to ensure cleaning the old paint off the metal and ensuring adhesion of new paint?

    Not everyone has a soda blast machine, but wondered if that might be the best prep for the new paint?

    Maybe a suggestion that works, and a Question of its value. I will attempt to let you know the results of how well the soda blasting works.

  2. I want to paint an add on metal sidewalk porch/cover for my senior neighbor. It has a white finish now which does not match her house. How can I insure that the paint wll hold for years to come?

  3. I have a exterior door that I replaced about 7 years ago because the door frame rotted at the bottom. The replacement door was a metal clad with a wooden frame. I painted the frame after cuts and before installation. I have the same rotting problem again. Does anybody built a exterior door frame out of fiberglass or something else other than metal that won’t rot?

  4. Thanks brother.
    Coloured iron sheets are So expensive here in Uganda and I want to roof my house with colored sheets. Now I want to get cheaper galvanized sheet and paint them. What are the materials to have for better quality work. Thanks and GOD blass you

  5. I have just applied a thick coating of aluminum asphalt roof coating to the inside of a 30 foot run of galvanized gutters. This run is rusted in the bottom and leaking. I am thinking this should work. If it holds up this winter, i will replace the gutter next summer and coat the inside when it is new to see if it extends the life of the gutter. What do you think???

  6. How to remove cement mortar “lumps” on galvanised sheet which is already factory painted? Can vinegar be used to soften the cement slowly or that it will be corrosive for CGI sheets?

  7. We have an old faded metal cover on a wheelchair ramp. I want to paint it a barn red but want the paint to adhere, best suggestions

  8. Once the metal has been cleaned and is dry, prime it using an exterior multipurpose latex primer, or a latex primer that is made specifically for galvanized metal. Topcoat with two coats of a high quality exterior latex paint. Any suggestions on the paint to use for galvanized metal?

  9. It would be cost effective if you used chemical paint remover and then clean to remove residue , prime with a water based exterior primer, such as SW DTM Primer Finish before applying top coats.

  10. I have a galvanised roof on the shed and it’s starting to rust don’t want rain getting in should I just paint it and if so with what

  11. I have a fire pit Propane . It is hammered metal and the top has started to peel the lacquered coat . How can I fix it ?

  12. Will this method work on a stock tank pool? I would love to paint the inside a blue color, but I am not having any luck with getting answers from several paint companies.
    The pool will be very lightly chlorinated, not salt water.


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