how to remove old protective film from stainless steel
If you've ever welded stainless steel, you know that heat tint is a very common occurrence. Heat tint appears as a discoloration and can take on a stunning "rainbow" appearance, as shown in these photos. The discoloration that you see is actually an oxide layer whose color is related to the temperature reached during the welding process -- the darker the color, the higher the
In stainless steel, the passivation process uses nitric acid or citric acid to remove free iron from the surface. The chemical treatment leads to a protective oxide layer, or passivation film, that is less likely to chemically react with air and cause corrosion. Passivated stainless steel resists rust. Felt cloth. Soft cloth. Silver polish. Step 1. Take the abrasive pad and use it to scrape off the thin layer of gold. It might take a while, but applying pressure on the pad as you move it back and forth ought to work. Use reasonable force as you’re only targeting to gold layer and not the base metal. Step 2.