Metal finishing Q&As since 1989

-----

Bubble wrap stains tin plating?

We buy a bracket with a tin plating surface. to store the bracket we cover it with pink bubble wrap, one week after, appear black stains on bracket, this stain only appear when we cover with bubble wrap.

Does bubble wrap produce oxide in the tin plating surface?

Oswaldo Montes
Buyer - Brownsville, Texas
2007

---

First of two simultaneous responses -- 2007

The answer is yes, it promotes corrosion on tin, especially if the part is the slightest bit damp or in high humidity.
Wrap the part in crystal paper, the thin stuff the high end stores wrap dishes in.
If the parts are small, the fillers for 30 dozen egg crates are wonderful for storing/shipping small parts.
Whatever paper you use needs to be a low acid paper. Some cardboard has a high sulfide content and this will really turn tin plate black.

James Watts
- Navarre, Florida

---

Second of two simultaneous responses --

Tin plating solution WILL NOT RINSE OFF, it has to be neutralized in an alkali. Go visit your vendor. Ask him to put the finished tin platuing work back thru the alkali cleaner, then rinse; then your bubble wrap, nor anything else, will stain.

Robert H Probert
Robert H Probert Technical Services

Garner, North Carolina

2007