Members timesofplenty Posted October 30, 2015 Members Report Posted October 30, 2015 Would like to try an idea with nickel silver in contact with veg-tan leather. I tried it with copper and got that waxy green build up. Anyone know if "German silver" will do the same? thanks Scott Quote
Contributing Member Bob Blea Posted October 30, 2015 Contributing Member Report Posted October 30, 2015 I think it will be a problem. That waxy green stuff you got is called 'Virdigris' and it forms when copper or copper alloys (like brass) stay in contact with a particular type of acid that is present in vegetable tanned leather. At first I thought you would be fine until I looked up how Nickel silver alloys are made, and it turns out they have copper in their mix as well. In fact German Silver can be as much as 60% copper so I think you may have a problem over a short time. Bob Quote
Members timesofplenty Posted October 30, 2015 Author Members Report Posted October 30, 2015 Thanks, Bob, that's what I suspected. I'd like to affix an etched flat piece to a wallet, What do you think about a protective sticker or paint on the back of the metal piece? Quote
Contributing Member Bob Blea Posted October 30, 2015 Contributing Member Report Posted October 30, 2015 I'd be worried that over time and use the wallet will flex and run off any protective coating. I thought a lot of conchos were made from Nickel Silver, why don't they react with belts and things over time? Maybe they aren't Nickel Silver? Quote
Contributing Member Bob Blea Posted October 30, 2015 Contributing Member Report Posted October 30, 2015 OK, I think I answered my own question a bit. Doing a little research it appears the conchos we all use are primarily made from cast Zinc alloys, also often called 'pot metal'. These are used because they are easy to work with and have low melting points, but they can really be any variety of metals alloyed with Zinc, with a common one being copper. However, Zinc alloys are apparently pretty good an being corrosion resistant to salts but are not good choices when dealing with acidic foods so they are not good for applications that involve cooking or food service unless they have a coating. So, I guess I'm still wondering why we don't see conchos discoloring because of long term contact with veg tan leather. Maybe just having copper in the alloy mix isn't enough to cause the problem if the alloy's chemical properties are good (think the difference between steel and stainless steel). So maybe this means German Silver (aka Nickel Silver) is OK too? Hopefully there are some actual metallurgists or chemists out there that can give a definitive answer? Quote
Members timesofplenty Posted October 30, 2015 Author Members Report Posted October 30, 2015 well heck, I'll try it and see what happens...will report back Quote
Contributing Member Bob Blea Posted October 30, 2015 Contributing Member Report Posted October 30, 2015 It's not a fast chemical process, it will probably take a while to show up. Quote
Northmount Posted October 30, 2015 Report Posted October 30, 2015 If the article is kept dry, not allowed to become sweaty or other moisture causes, very little verdigris should occur. I have some leather harness that is many years old. The copper rivets don't show any verdigris. Yet other work has been moist enough to begin "growing" the green stuff! Tom Quote
Members ChuckBurrows Posted November 1, 2015 Members Report Posted November 1, 2015 s others noted it's not just the metal but whether moisture is part of the problem. While GS aka nickel silver contains a lot of copper, it generally does NOT form verdigris like copper or brass due to the nickel content. That statement is based on 50 years of using German Silver. Quote
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