Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
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Hobbyist has tin plating problems
1995
Q. I'm presently making some little shields out of copper sheet for a printed circuit board and would like to know what I should spec for a finish. I made a box for a power supply before out of 22 GA steel and specified just a straight tin plate. I did this because I wanted to solder the box together. The plating seemed to come back fine and the box assembled well. Since I always find finishing one of the most confusing parts of any project I was hoping that this web site could be a source of information for me in the future. I have been told that maybe a hot tin plate would be better. What is the difference between hot tin and just tin? Did my steel box have to go thru extra plating steps to be tinned? Was there a better finish I could have used? As you can see, I have lots of questions and I would surely like to have a place I could get answers. My next project is using some perforated steel sheet so I will need to plate it too! Any comments or help greatly appreciated. Peter
Peter Chapman
A. Tin plating of electronics, and for solderability, can be a specialized field, and is one where my hands-on experience is limited, so I hope that some reader more knowledgeable on this than I will jump in and straighten us both out!
But I understand that there has been some movement in the Far East towards applying tin by hot dipping (into molten tin) as opposed to electroplating, for reduced cost and improved solderability. Another technique, I believe, is reflow--where the tin is electroplated, but then heated to the melting point for grain refinement.
Practically speaking though, electroplated tin is a fine finish, readily available, and I don't know of any job shops that offer hot dipped tin anyway. For onesy-twosy applications, if your tin solders well, I don't think you need additional steps.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
1995
A. While tin electroplate is fine, electroless tin on copper usually provides sufficient corrosion resistance and solderability at reduced cost to electroplating. Hot dip tin is fine for large quantities. For onesy/twosy parts, hobby quantities of electroless tin solution (1 pt / 1 qt) can be purchased off the shelf from many electronics / project sources. There is an electronics oriented chemical company (photoresists/etchants/tuner cleaner/etc.) out of Canada that produces and markets an electroless tin solution that is available in the US
Jeff Albom- El Granada, California
1995
Ed. note: That company out of Canada is, we believe, out of business. We think their successor is dalpro.net. But you can get electroless tin plating solution in small volumes from Amazon.
and probably elsewhere.
A. Hot dip tinning of very small electronic parts was performed in a captive shop in New Jersey about 10 years ago. And it was a performance requiring skill and grace. The scrap rate was much less than 1/2 of 1%. If done poorly, you could have scrap of 10 to 15% with no problem.
Regards,
Tom Pullizzi
Falls Township, Pennsylvania
2001
Q. I am also retired and would like to play around with tin electroplating some Scripto UV lighters and some very small hand size metal steel boxes--I already bought the two bars of tin and also have a 5 AMP 32 Volt variable voltage & power --DC supply with digital readouts.The plating would be done outside under a roof overhang.
What dry electrolytes should I get that do a nice job without calling in the HAZMAT people to a private house.
Thank You ,
Mark
- Staten Island, New York
October 9, 2012
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