Summary for removing tin coating from brass Discussion
Removing tin coating from brass can be done with either an anodic electrolytic alkaline stripper or a chemical dip. In the answer, Ted Mooney, P.E. says an anodic alkaline stripper using 10% NaOH at 25 °C is one option. He also lists chemical alternatives: 50 g/l in 100 ml/l H2SO4, or 80 g/l FeCl3 in 156 ml/l glacial acetic acid with 125 g/l copper sulphate. Mooney notes that the ferric chloride solution can leave the brass clean once the tin is gone, but the parts must be removed immediately after the tin has been stripped. He adds that 5% H2SO4 with 10% H2O2 will also work, but warns it will dissolve almost any metal, so it is much less selective. The thread is a practical removal discussion rather than a debate, with the main caution being to stop the process as soon as the tin is removed.
Q. Is there any way to remove Tin Coating from Base Metal? The base metal is Brass.
Saket Gupta
– Yamuna Nagar, Haryana, India
2003
A. Yes. Either use an anodic electrolytic alkaline stripper (10% NaOH 25 °C) or a chemical dip. The chemical dip can be either 50 g/l in 100 ml/l H2SO4 or 80 g/l FeCl3 in 156 ml/l glacial acetic acid
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or
Amazon [affil link] with 125 g/l copper sulphate. The ferric chloride
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eBay or
Amazon [affil link] solution will leave the brass clean once all the tin has been removed, so long as the parts are removed immediately after all the tin has gone. Alternatively you can use 5% H2SO4 with 10% H2O2, but this will dissolve almost any metal!
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2003
Q. Can it be economically feasible to recover tin in a process to remove tin from brass? If so, how can I do that?
Fabricio Mendoza
– Monterrey, NL, Mexico
May 20, 2013
A. Hi Fabricio. Tin is not a semi-precious metal, but it is the most costly base metal, say 10x more expensive than zinc and about 3x as costly as copper. So recovery is possible; in fact, my very first job interview was with a corporation whose business was recovery of tin from scrap. Yet it still may be impractical for you depending on your situation; please give us some clues because we don’t know if you are working in a refinery or in a plating shop, or if you are a scrapper with just a few pounds of copper. Thanks!
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
May 23, 2013