Nickel silver discoloration?

solphilos

solphilos

Joined
Oct 17, 2009
Messages
1,076
Hello gentlemen. Today a started carrying my #35 Churchill in a leather slip for the first time and found the bolsters to have oxidized or discolored; almost to a muted brass color.
Is this merely normal patina, or has the tanned leather somehow reacted with the copper in the bolsters?

Its something I haven't encountered before, but I kind of like it. I'll post pics tomorrow when I get some decent lighting.
 
solphilos said:
Hello gentlemen. Today a started carrying my #35 Churchill in a leather slip for the first time and found the bolsters to have oxidized or discolored; almost to a muted brass color.
Is this merely normal patina, or has the tanned leather somehow reacted with the copper in the bolsters?

Its something I haven't encountered before, but I kind of like it. I'll post pics tomorrow when I get some decent lighting.
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Ive had this happen to me on a knife or two, and they were all in slips / sheaths I made from leather scraps.
My guess is that the leather wasn't veg tanned and had caused this.
Where did you get your slip from ?
 
Yeah, nickel silver will turn yellow. I've seen it usually happen on knives that are let sit for a while in humid-ish environments. Leather usually has some moisture in it. You can bring it back to that ivory-white-metal shine with some Flitz or your favorite metal polish.
 
Must be the leather, the hide may contain acids that draw out the brass composition in the bolsters. It's never a good idea to leave knives in pouches/sheathes for other than actually carrying them.
 
Hickory n steel said:
Ive had this happen to me on a knife or two, and they were all in slips / sheaths I made from leather scraps.
My guess is that the leather wasn't veg tanned and had caused this.
Where did you get your slip from ?
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From the place that doesn't charge to ship knives. It doesn't feel or smell like veg tan, but I could be wrong.

traumkommode said:
Yeah, nickel silver will turn yellow. I've seen it usually happen on knives that are let sit for a while in humid-ish environments. Leather usually has some moisture in it. You can bring it back to that ivory-white-metal shine with some Flitz or your favorite metal polish.
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I may, but I think I'm liking the tarnish a bit.

Jathes said:
My Churchill turned a bit "brassy" after I left it in a slip in my pocket and wore a tychem suit for about 10 hours. It was pretty humid in there.
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traumkommode said:
Bingo.
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sitflyer said:
I kinda like the look when NS turns a brassy color, it kind of warms the look of it a bit.
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I think I like it also, it looks good with the golden and brown hues in the bone.

Will Power said:
Must be the leather, the hide may contain acids that draw out the brass composition in the bolsters. It's never a good idea to leave knives in pouches/sheathes for other than actually carrying them.
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This has been my suspicion. The knife was in the slip for maybe an hour while I was inside in the a.c., so I'm leaning towards acids due to the speed at which this occurred. But its been humid around here lately so I cant rule it out.
 
Most leather is tanned with very harsh chemicals that will affect metals. Generally it can be buffed out of NS with brasso or a good semichrome. Vegetable tannins typically do not have any side affects.
 
The slip may be made from chrome tanned leather. A long time ago I made a pocket slip from a leather scrap and kept a carbon steel Schrade stockman in it for years and years with no effect at all. I also made a little bullet pouch out of a different scrap and within a short time the brass of all the 22LR rounds that I left in it corroded.
 
I've noticed that more of my German-made folders seem to have NS bolsters that 'yellow' more than the domestic (U.S.-made) ones do, just in exposure to the air (none are in leather slips). I assume they've utilized a different compositon for the alloy. I can think of at least a couple from Hen & Rooster, and some 'Buck Creek' folders made in Germany that yellowed noticeably. In particular, the Buck Creek knives' highly-polished bolsters have taken on a beautiful, almost gold-like tone; I've opted to let it be, instead of polishing it away.
 
Obsessed with Edges said:
I've noticed that more of my German-made folders seem to have NS bolsters that 'yellow' more than the domestic (U.S.-made) ones do, just in exposure to the air (none are in leather slips). I assume they've utilized a different compositon for the alloy. I can think of at least a couple from Hen & Rooster, and some 'Buck Creek' folders made in Germany that yellowed noticeably. In particular, the Buck Creek knives' highly-polished bolsters have taken on a beautiful, almost gold-like tone; I've opted to let it be, instead of polishing it away.
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I find this to be true also I have a Bulldog with ns bolsters and shield that tarnishes from air within weeks of being polished.
 
Regarding a possiblility of the leather's tanning causing a problem, I'll just throw this in:

I have an old Western L48A fixed blade that was given to me by my father some 45+ years ago. I've gotten away, for the most part, with keeping the knife in it's leather sheath for that entire time. We've always lived in a very dry climate, in the southwestern U.S., so I haven't had any issues with rusting on the blade itself, even stored in it's leather sheath the whole time. The only issue I've had is, the brass guard kept showing some verdigris in a very specific, localized spot, where it contacted the leather. I'd periodically take the knife out and polish away the verdigris, then put it back into the sheath.

Just in the past few months, I finally tried something that I'd seen recommended online somewhere, to nip the verdigris issue in the bud once and for all. I removed the knife from the sheath, and put the sheath in a large Zip-Loc bag (1 gal. size) with enough baking soda to completely cover and fill the sheath. I just set the bag aside for a month or more (I dated the bag with a Sharpie), and made a temporary blade cover from cardboard for the knife, in the meantime. After at least the month, or maybe nearly two, I pulled the sheath out of the baking soda and gave it a good rinse in the sink. The baking soda rinses away easily, both inside the sheath and out. I used a clothespin to hang the sheath on a clothes hanger in the closet, to dry out after the rinse. I left it there for a week or more, to ensure it was completely dry. Then, after all that, I finally put the knife in the sheath again. I pull it out of there every week or so, to look for any new staining or verdigris. It's gone and done; no problems with verdigris on the brass anymore, after 45+ years of 'tolerating' it. :)
 
I bought a NIB Queen from 2003, the side of the knife facing down for all of those years had the same brassy tarnish on the bolsters. Old rag and some polishing compound took care of it pretty quickly.
 
Obsessed with Edges said:
I've noticed that more of my German-made folders seem to have NS bolsters that 'yellow' more than the domestic (U.S.-made) ones do, just in exposure to the air (none are in leather slips). I assume they've utilized a different compositon for the alloy. I can think of at least a couple from Hen & Rooster, and some 'Buck Creek' folders made in Germany that yellowed noticeably. In particular, the Buck Creek knives' highly-polished bolsters have taken on a beautiful, almost gold-like tone; I've opted to let it be, instead of polishing it away.
Click to expand...

I also find this, and with contemporary Sheffield-made folders too. I think they use cheaper NS, which has a higher brass content.

Obsessed with Edges said:
Regarding a possiblility of the leather's tanning causing a problem, I'll just throw this in:

I have an old Western L48A fixed blade that was given to me by my father some 45+ years ago. I've gotten away, for the most part, with keeping the knife in it's leather sheath for that entire time. We've always lived in a very dry climate, in the southwestern U.S., so I haven't had any issues with rusting on the blade itself, even stored in it's leather sheath the whole time. The only issue I've had is, the brass guard kept showing some verdigris in a very specific, localized spot, where it contacted the leather. I'd periodically take the knife out and polish away the verdigris, then put it back into the sheath.

Just in the past few months, I finally tried something that I'd seen recommended online somewhere, to nip the verdigris issue in the bud once and for all. I removed the knife from the sheath, and put the sheath in a large Zip-Loc bag (1 gal. size) with enough baking soda to completely cover and fill the sheath. I just set the bag aside for a month or more (I dated the bag with a Sharpie), and made a temporary blade cover from cardboard for the knife, in the meantime. After at least the month, or maybe nearly two, I pulled the sheath out of the baking soda and gave it a good rinse in the sink. The baking soda rinses away easily, both inside the sheath and out. I used a clothespin to hang the sheath on a clothes hanger in the closet, to dry out after the rinse. I left it there for a week or more, to ensure it was completely dry. Then, after all that, I finally put the knife in the sheath again. I pull it out of there every week or so, to look for any new staining or verdigris. It's gone and done; no problems with verdigris on the brass anymore, after 45+ years of 'tolerating' it. :)
Click to expand...

Good tip :thumbsup:
 
Thanks for all the tips guys, this indeed is a reaction to the leather as it also quickly tarnished the two nickel silver pins in my #35 Caplifter.

Here's a pick of the Churchill and the offending slip:
IMG_20180226_102647.jpg
 
You can polish it with a metal polish to get it shiny silver again. Be careful with metal polish that you don't get any of the black residue it creates on lighter colored bone or stag handles, especially in the fine line between the bolsters and the ends of the handles. I have accidentally discolored some light-colored bone that way.
 
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