Summary for stainless steel pickle formula Discussion
stainless steel pickle formula threads discuss ways to remove TIG weld discoloration and improve corrosion resistance on 304 and 316L stainless steel. In the first answer, Lee Kremer of Stellar Solutions says TIG welding usually leaves the least discoloration, but some cleanup is still needed. He lists four options: a nitric acid/hydrofluoric acid pickle paste, grit blasting with non-iron grit followed by passivation, brushing with a 316 stainless brush or Scotchbrite and then passivating, or using proprietary electrical removal chemicals and equipment. He warns that the acid paste is very hazardous. In the later Florida sign-shop question, the writer asks for a U.S. equivalent to a German brushing-on pickling paste for welds on mirror-finished 316L letters, but the excerpt does not include a direct product recommendation. The discussion emphasizes careful post-weld cleaning and passivation, especially where corrosion resistance matters.
Q. What chemicals or chemical pastes are effective in removing discoloration from 304 stainless steel after T.I.G. welding? If the compounds are proprietary, who is the supplier and where can they be bought?
Lin Emery
studio – New Orleans, Louisiana, U.S.
2003
A. There are a variety of ways to clean the weld discoloration. TIG welding usually leaves the least of this problem, but you always have some.
1) Use a nitric acid/ hydrofluoric acid paste (pickle paste). This is very hazardous and should be handled with extreme care and knowledge.
2) Grit blast with non-iron containing grit, then passivate.
3) Wire brush with 316ss brush or Scotchbrite cloth to clean off discoloration, then passivate.
4) Electrically remove the discoloration with proprietary chemicals and equipment. This method can be fast and easy.
Contact us if you want info on this. We cannot name it here.
Lee Kremer
Stellar Solutions, Inc.
McHenry, Illinois
2003
March 14, 2011
Q. We are a sign shop in Florida. We work with 316L stainless steel letters which are sold to the marine industry and are asking for help improving corrosion resistance of our letters.
The letters are 4mm thick 316L stainless steel. The fronts and edges are hand-polished to a mirror finish. Studs are welded to the rear of the letters – to allow handling during polishing – and later removed. The areas that had the studs welded on are sanded down and chemically cleaned.
After the polishing process, threaded 316 stainless steel CD-studs are welded to the back of each letter.
We would like to chemically treat the welds and the sanded areas (from prior welds) on the backside to prevent corrosion without damaging the mirror finished front and edges.
We saw a company in Germany brush on this pickling paste around the welds and the sanded areas with great success: https://caree-chemie.de/eng/index_engl.htm
We are looking for an equivalent product / application here in the U.S.
All help is appreciated!
B K [last name deleted for privacy by Editor]
sign maker (business) – Florida, USA
Ed. note: This RFQ is outdated, but technical replies are welcome, and readers are encouraged to post their own RFQs. But no public commercial suggestions please ( huh? why?).