plating, anodizing, & finishing Q&As since 1989
Quality issue of rusting of tin plated parts
August 23, 2010
We are facing Quality issue of rusting of our tin plated parts in our processes.
We want the probable route causes & their remedies for rusting of tin plated parts (plating thickness - 5~8 microns)
QA - Pune, Maharashtra, India
August 24, 2010
Generally, 5 to 8 microns seems pretty thin for barrier layer plating on steel, and a probable solution to the rusting issue is to employ heavier plating.
I'm sure the readers would like to help you, but please realize that your question can also be worded as follows: "Please give me full detailed instructions of every pretreatment, plating, post treating, handling, and packaging step for quality tin plating. Must be applicable to all rack, barrel, and continuous tin plating lines, both bright and matte process, and both stannous and stannate systems. And for exposure to all environmental conditions. Also describe in detail a competent quality assurance program for same" :-)
It would be hard to answer that in a 300-page book. You need to give us some starting points by telling us whether you do rack, barrel, or strip plating; bright or matte; stannous or stannate, whether the parts rust at the high current density edges or the low current density center. Is this is a new problem after years of successful plating, or a problem you have suffered for years, or something that popped up last week?
Please try to flesh out your situation. Thanks!
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey