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Removing Brown Tarnish on SS316

We are a cleaning company and people ask us to remove brown tarnishing from the SS 316 handrails. It is occurring on number of jobs near the ocean. It is taking up to 1 hour/metre to remove the tarnishing. When we remove the tarnishing we coat it with a clear coat wich stops the problem re-occurring. The problem is that it isn't economically viable to take so long in the cleaning process. Can someone help me out.

Stephen Scarpin
- Melbourne,Victoria, Australia
 

Brown or tan colors on stainless are often iron oxides; iron oxides are usually soluble in low pH solutions and can be removed with acids. Try a small inconspicuous spot, and if it works, there are many acid cleaners available to do the job. Just make certain you rinse thoroughly and completely, especially if you are using phosphoric or hydrochloric-based cleaning solutions (as residuals can damage the metal).

Dale Woika
- Bellefonte, Pennsylvania, USA
 

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Stephen:

The brown coating on the surface is probably iron oxide. It can be removed easily and safely with proprietary products that are on the market containing citric acid. If the railings were not passivated after manufacture, there could have been free iron on the surface from the manufacturing process that later rusts. See our web page for more information on this.

Lee Kremer
Stellar Solutions, Inc.

McHenry, Illinois