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Pickling without hydrofluoric acid

Q. Has anyone got a recipe for a commercial strength cold stainless steel solution,without using hydrofluoric acid?

Rob Atkinson
- Newcastle upon Tyne
2003

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SeeASTM A380 for pickling solutions. The usual substitution for HF is ammonium bifluoride, see letter 18607 . Commercial solutions usually also contain proprietary inhibitors, for which you may try the Chemicals link below. Ammonium persulphate+sodium fluoride was recommended for etching glass in letter 18787 .Perhaps, you can test this on SS and report back.

Ken Vlach [deceased]
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.
2003

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I have been in contact with the technical department of the company who supplies my Electropolishing solution (Electropol 201). The solution is hydrofluoric free but does contain sulfuric. I am advised that I should pickle as per The Canning Handbook [on eBay, Amazon, AbeBooks affil links] for sulfuric anodising method. This will have great possibilities as there will be no need to passivate between processes. The only problem I can see is I will need to top up with sulfuric from time to time. Has anyone else used this method?

Robert Atkinson
- Newcastle,Tyne & Wear, England
2003

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