Where the
world gathers for metal finishing
Q&As since 1989


-----

My chrome plater stripped my gun parts. What's this leftover residue?

July 17, 2009

I've looked at many of the questions on this site regarding stripping chrome, and I don't see a ready answer to my dilemma. Sorry if it's been posted previously.

OK, so I followed the advice here and had a chrome shop strip the chrome and underlayment off some steel gun parts for me (rather than try it myself). He confirmed he did this in a stripping tank, as opposed to blasting or sanding.

The parts now have a residue on them that is dark, and slightly sooty. Not smooth. Although it doesn't come off with casual contact, it will take a fingerprint (due to the oil in skin, I suppose). I'm OK cleaning it off, but am cautious about the best approach.

What is this stuff and what's the best way to remove it in preparation for cold bluing? Will it come off in a rust-removal electrolysis setup (washing soda [on eBay or Amazon] , water, rebar, trickle charger)? Or is it as easy as a Nevr-Dull polishing wad? I don't want to attack it w/ steel wool if I can avoid it due to the nooks and crannies, and I want the edges to remain sharp. Thanks in advance.

Justin Turney
hobbyist - Spring, Tx, USA

---

It sounds like the plater stripped your parts in sulfuric acid with reverse current. This method will attack the underlying steel to some extent, and the black residue is carbon. Scrubbing with a stiff brush, water and detergent should remove most of it.

Jeffrey Holmes, CEF
Spartanburg, South Carolina
July 23, 2009

Thanks for your response! BreakFree CLP cleared things right up with very little effort.

Justin Turney
- Spring, Texas, USA
July 24, 2009