Removing Verdi Gris From Bone

Atiger

Atiger

Joined
Mar 7, 2016
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736
This old Ulster is slowly turning green from a Verdi Gris that's probably emanating from the the brass pins of the handle. It's only on the pile side right now but I'd like to remove it before it gets worse. Surely there's a soaking solution that will remove this but I have no idea what it is. Any suggestions or recommendations from anyone who may have dealt with this problem in the past?

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I'd leave it untouched if it were mine and just keep the outside clean and lightly oiled. Very unique. Interesting how it's staining the bone handles.
 
I don't think there's much you can do, short of removing the scales and cleaning up, but that's clearly a no-no.

It's one reason I'm not over keen on brass liners with light bone or Stag, at least yours is an old knife. Some of my CASE and GEC knives from recent times have already been stricken. Brass smells funky too....:barf:
 
Nothing you can do. However, even if you could remove it, that would destroy some of its collector value.
 
Usually, collectors just wipe off solid verdigris with a rag. Some problems with soaking the knife in a solution are that it may spread the green around. That may have happened a little bit already. The solution may also affect the dyed color of the covers. But for whatever it may be worth...Verdigris is soluble in HCl (muriatic acid)--it is very caustic so read the MSDS and use appropriate safety precautions. HCl is very corrosive to metal also.

I recommend not messing with it.
 
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I'd try an ultrasonic tank with a solution of hot water and baking soda. And i would try to remove it as it's a destructive growth. But that's just me.
 
I would leave it be, it adds character to the knife! Also- this place is great becasue I get to learn new words while looking at knife pictures:)
 
Thanks for the replies, everyone - I'll probably just leave it alone and look out for another one. Certainly don't want to disassemble or dip it in HCL but it does detract from the natural beauty of the bone.
 
I think the barlow looks fine. Old knives look old.... unless they're on eBay and then every bit of the original finish is removed... maybe some of the original parts too. ;) It's sort of funny how antiquing is somewhat popular for new knives and refinishing is so popular with old knives. The grass (or verdigris ;) ) is always greener on the other side. :D

eisman's suggestion of using an ultrasonic cleaner would probably remove years of junk stuck inside the parts of the knife. It wouldn't do any harm if you dry it thoroughly afterwards. But I'm not sure it would have much affect on the discoloration (except from dirt). In my opinion, it should be pretty stable as is.
 
supratentorial said:
I think the barlow looks fine. Old knives look old.... The grass (or verdigris ;) ) is always greener on the other side. :D
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Jake, so true. :D I have a couple of bone and stag growing more green then I would like so I've been following this thread closely, hoping there might be a solution. Yet, at the same time I liked the OP's knife as is and wouldn't change a thing. So, green on mine... no thank you. Green on yours... just fine. Who would have thought... :confused: :)
 
Wait, what's the other side look like? Those pins look like they were buffed shiny. Are you sure that isn't residue from buffing off any built-up patina?

Just curious...
 
Actually, the other side isn't as discolored but is starting to show a little green at the interfaces of the bone and the brass pins and liners. The pins shine because I tried removing the stains using Flitz but it didn't really have any effect on the handle material - the stains remained unchanged. The green color seems to be IN the bone rather than ON it.
 
Ah, ok. Thanks for the clarification.
 
The brass and copper parts should be pretty stable but the color could still spread from the metal to the bone covers. Keeping the bone covers dry and free from solvents or oil is the simplest way to minimize the spreading of the green.
 
I would simply take the knife to a hand basin - then use and old tooth brush and while holding the knife in one hand allowing the warm water to pool and just cover the knife - use the old toothbrush and and some good old ordinary soap and just clean it.
You just cannot hurt the knife in any way doing this. While you are at the Hand basin - work the soap into the joint and exercise the blades - then work the blades again while under a slightly hot tap.

Take the knife to your garage and using compressed air and air gun - blow out all the excess water.

Carefully soak the joint with Wd40 work the joints- blow out again and a drop of Mineral oil into the joint. Good to go.
 
I came across this article on verdigris a while back. It's probably the most detailed I've seen, in terms of what it is and some possible methods for removing it. I haven't tried any of the methods suggested, so no guarantees from me:

www.oregonknifeclub.org/Verdigris.pdf

One method suggested as being very effective is Hoppe's #9 gun solvent (not the oil, but the solvent). Seems to make sense, in that it's made to remove (dissolve?) copper deposits left by ammo in gun barrels (verdigris is copper acetate, according to the article). If trying it, I'd start very, very small; maybe applying it to a very localized spot with a Q-tip or something, just to see if it works or makes a visible difference.


David
 
Obsessed with Edges said:
I came across this article on verdigris

One method suggested as being very effective is Hoppe's #9 gun solvent (not the oil, but the solvent). Seems to make sense... If trying it, I'd start very, very small; maybe applying it to a very localized spot with a Q-tip or something, just to see if it works or makes a visible difference. David
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David, I just finished trying Hoppe's solvent on small sections of some users (with Q-tip). On verdigris around a rivet in stag it was easily and completely removed. I suspect because it was on the surface only. On white bone and ivory there was no change, possibly because the verdigris was deeper (below surface stain). Will be interested to hear your and/or others results. -James-
 
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Be careful with the Hoppes, though. I've found it to be nasty stuff. I'd flush everything out and reoil after using it.
 
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