Why Paint Stainless Steel

As for painting passivated stainless steel—Why? Why would anyone want to get rid of the passivated layer and lose the benefit of its corrosion protection?


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Q. I read with interest your answer to the Cold Zinc Phosphate question in the March 2008 Painting Clinic. I, too, am skeptical about the salesman’s claims for a cold (with water right out of the tap) zinc phosphate. The lowest temperature that we would recommend for running a low-temperature zinc phosphate is 100–110°F, and this product has been specially formulated to operate at this temperature. As for cleaning, you are correct about the normal temperature requirements for most “low-temperature” cleaners.

As for painting passivated stainless steel—Why? I never really understood the concept. They are trying to paint a material that was developed to exist without a paint film. The surface of the stainless steel is passivated for a reason. Why would anyone want to get rid of the passivated layer and lose the benefit of its corrosion protection? I never understood why people wanted to paint their DeLoreans (well, they wanted to stand out) and then would complain when the paint wouldn’t stick for long to a surface that was never meant to be painted in the first place.

Please forgive my rant about painting stainless. It’s been a pet peeve of mine for a long time. As always, I enjoyed your column. N.F.


A. It’s funny you should say that, since you work for a large paint company, which is also the same company that gave me my first job just out of college. When I was president of the Pittsburgh Society for Coatings Technology, I asked the owner of a local paint company a similar question. I asked him why anyone would want to paint a brick house. I went on to tell him that I built a brick house, not because the big bad wolf couldn’t blow it down, but because I didn’t want to paint it. His answer was, “Shame on you, and you’re a paint chemist!” He told me that people painted brick houses for decorative purposes. It dresses up the neighborhood. I guess the same applies to painting stainless steel. Although I must admit that I tend to agree with you. Therefore, shame on me. 


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