doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Chemical reaction from guncase

I had trouble with the nitride finish on my K-80 discoloring and a friend used a Birchwood Casey lead remover cloth to clean it. It was fast, easy and the results were SUPER!!! Just use it like a silver polishing cloth and lightly oil the reciever when you finish.
bill

If it is silver? and I suspect it is, it may not be so much plated, as a silver "wash" similiar to what is done in gold to the inner works of some doubles - very thin would be a kind description. If one has natural gas for home use, heating etc. it won't take long to oxidize silver to "black" for some reason probably the inherint moisture. I don't have a Merck Index to find what all turns silver black, could be a lot of chemicals. Jag, I would be reluctant to leave on any type of slip-on due to the chemical retained by leather-isn't lye? (caustic soda) used in tanning leather and caustic residue could easily be present add a little moisture and bingo ruined finish. As far as rubber goes it breaks down with time and the resultant "brew" might be a good finish remover. --- John Can.

John,
The silver nitrate solution process is a form of electroless plating. Agreed, it is super thin. Over the years, mfrs like Browning/Miroku, Win/Kodensha, and others have tweaked the methods and alloys. I recall one Citori of silver nitrate finish that was clearcoated from the factory, but soon wore off in the usual places from carry. The silver finish turned a gray/black in the area of wear until it too wore thru to the steel. I had a 101 Pigeon with the same silver nitrate finish and similar things occurred.

For a silvery finish that "Won't" wear off --- try Metalife. It is a chromium stainless finish. The best wearing, non staining finish I have ever seen --- used it for years on some client guns. Ken

I'm attempting to reach the owner of the two guns. Another friend just corrected me about the case material - these two cases are oak and leather and not plastic cases as I had previously reported. The (2) guns are high end Perazzi's and the owner lives in Virginia not SC. I'll attempt to get additional details concerning the year that the guns were manufactured, the model plus any additional info he can add. I'm also curious to learn if only a portion of the action in contact with the case turned black or if it was the complete action.

Perhaps a bit OT, but I learned from experience not to wipe my Merkel silver nitride with a silicone impregnated cloth, as it turns the silver nitride to an ishy rusty brown that is difficult to remove.

John

Could be the very air as noted depending on the "silver" coating.

More likely to be glue or process used on the leather. Ask anyone carrying a silver item in a Coach purse...

A clue is usually that the problem generally occurs more on the side away from that resting on a surface.

IN GENERAL, a light oiling should help prevent this.

One test might be to take the gun out and replace it with a piece of silverware for a week or so.

Might also suggest wrapping the guns in sleeves made of Pacific cloth which many of us do for transport in leg o'mutton cases.

Mystery solved (maybe). Cases are OAK and leather. Leather is hygroscopic, and oak has tannins that will turn ferrous metals black. That's why you seldom see steel or iron hardware on vintage oak furniture. The usual brass hardware was not just for looks, it was to keep the tannins from attacking steel hardware. Topic is covered extensively in vintage cabinetry and contemporary refinishing books. The moisture attracted by the leather in a relatively humid climate combines with the tannins and creates the black color on the guns.

Where are the chemists?

Posted on 10/7 in the morning:

"I think the resident alchemists here should forget about the black tarnishing common to silverware........ I suspect another reaction is at play......"

Hmmm, I don't have this problem in any of my oak and leather cases. Just saying.