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304SS Ag equipment gets rust spots

We have been selling Ag. packing eq. made of 304 stainless steel for about 8 year. We recently got our first complaint about our eq. rusting or corroding. They sent us pictures that showed small rust spots all over. Because the eq. in the picture has 304 stainless from at least two different countries, & three different steel mills. We believe they are exposing the steel to some type of cleaner that is breaking down the passive film on the stainless.Maybe chlorine. Do you have any suggestions on how to handle the chlorine problem, to remove the rust and help restore the passive film. If we learn how to deal with this problem, maybe we can send instruction with our eq.on how to avoid this type of problems in the future.

Thanks in advance Bob

Robert Williamson
A&B packing eq.co. - Hartford, Mich., USA
2004

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Bob,

You definitely need to stop them from using any cleaner containing chlorine. citric acid formulas can be used instead to clean and re-passivate stainless, even on equipment in the field. Let us know if we can help.

Ray Kremer
Stellar Solutions, Inc.

McHenry, Illinois

2004

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304 stainless will not rust red, it pits and discolors to white or dull grey or black, depending on the cause. If you are sure you're seeing red rust then you have a contamination problem, not a chlorine problem.

A Citric cleaner may well be the solution, especially if it can pickle the iron off the surface and passivate what's left. If your problem is tougher than that you really need to check your material to be sure it is what they say it is.

Jeff Watson
- Pearland, Texas
2004