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Maintenance headache: corrosion of fasteners in plating shop

December 16, 2010

I work on piping in a plating shop and when it comes time to repair a pipe, the pipe clamps and fasteners are often corroded and the pipe needs to be cut off. In the past they were only made of the standard cast steel with no coating, which obviously didn't work and turned to pure rust powder. When I installed new systems back in June, we 7/10 EN plated the cast steel pipe clamps and followed up with epoxy powder coat. These are still going strong but the 304SS fasteners are corroding in the vicinity of HCl tanks and becoming stuck.

1) What would be a lubricant/grease to install on the threads that would last about six months?
2) The 304SS fasteners are corroding badly around the muriatic pickling tanks. We cannot afford Ti or Alloy C-276 fasteners, and I cannot powder coat all of the threads. Would 5/10 Hi Phos EN allow 316SS fasteners to hold up to the environment for at least a few months?
3) The pipes are plastic so there is no galvanic corrosion between the pipe and the fastener, but is there between 304SS and mid-phos nickel plate?

Alexander Peterson
shop employee/student - Rochester, New York

We coat all of our stainless steel flange bolts with anti-seize compound ⇦this on eBay or Amazon [affil links] . There are several out there, I am not sure if one works better than the others. This may not last forever, but combined with the stainless, it works pretty well.

Jim Sweney
- Indianapolis, Indiana
January 7, 2011

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Plain old Vaseline is as good as anything.

Jeffrey Holmes, CEF
Spartanburg, South Carolina
January 10, 2011