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From: Products Finishing,
Products Finishing magazine
I am having an old steel spiral staircase removed from a public school and then refinished and installed in my home.
Q. I am having an old steel spiral staircase removed from a public school and then refinished and installed in my home. I don’t want it painted, as I know eventually it would peel off and be a mess. My contractor was supposed to have it powder coated, but it appeared to me that it was spray painted with liquid paint instead of powder coated. Am I correct in assuming that it should not have paint runs, bubbles or be able to be scraped off? It was also painted black, and it was supposed to be nickel. This all took place on a Friday, and he called me back in the afternoon and stated that he would be able to install it the next Thursday. Is it possible to have a large item like this (there is also a cat walk approximately eight feet long to be installed) refinished properly in this short a time? L.T.
A. Yes, it is possible. I would be more concerned about the process than the time, though. The old coating must be thoroughly removed by blasting. After blasting, the surface may be dusty and still have traces of the old coating.
Powder washing with wand and hand, working to remove any traces of the old coating will fix these problems. So now assume you have a very clean piece of metal with a blast profile of at least 1.5 mils of peak to valley distance. It should be coated as soon as possible to avoid flash rusting.
Next, it should have a coat of powder primer added to provide the necessary corrosion resistance, followed by a suitable polyester topcoat for weathering resistance. The total thickness of the coating should be around 6–10 mils when it is done.
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