Featured Homemade Verdigris formulas

Oh boy. Use caution if you try any of these treatments! It looks to me like most of these either:

• Won't do anything.
• Will strip a coin's patina.
• Are potentially dangerous.

Use caution, and try these on a coin you don't care about first, is my advice.

 

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Thanks Paul. Absolutely. I will be very careful. BUT keep in mind, this J Wiener, will in time, effectively be destroyed...so, I'd rather get damage off, without killing the medal.

 

Yep, tried olive oil a lot, though never heated. The same results, it removes the green but leaves a darker area. Still an improvement. I hedge my bets by putting all such copper coins into a container by themselves. None of the coins I've done this with are of much value so no real loss or gain either way.

 

lol. thanks ernie. Greatly appreciate your input. This piece cost me a few hundred. It's one of the rare pieces of the Wiener set. BUT, I'd rather have a pretty medal to look at than green splotches. I'll wait for more input from other experts before I try my hand at it. Lol. Picture is attached again for those who can offer their guidance. Again, I know I'm between a rock and hard place...the vedigres will destroy (has been destroying) the material if left on, but if I get it off, it will leave a spot. Well, I'd rather have a medal saved vs. destroyed, even if it gets a 'unc details cleaned' by the grading companies...as long as the over appearance isn't destroyed, if that makes any sense.

 

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On bronze indian head cents that have light BD after experience have achieved good results with Sodium Sesquicarbonate as directed in a glass container with a sealing lid: 1-2% for coins with a desirable patina or 5% for one day if BD is bad. I will usually warm the distilled water to dissolve the powder and then place the coin in for a day or two, checking the patina and observing the verdigris. After a day i have often found soft sable brush in the solution gently will remove verdigris. I have found too strong a solution or too long can change the patina bluish...which is not ideal, so go easy. I will also alternate days with plain distilled water to steal more cuprous metal ions. I have found that even the distilled water soak really does loosen dirt dissolve the verdigris. Change water daily or every two days. I don't do this for more than a week. I'm not looking for shine or perfection just a reduction of cuprous metal and stabilization. Follow same standard for drying and storage. I do use silica packets in my case and have not seen any return of BD for a year now.

 

This thread taught me how to farm verdigris to make a green pigment thx

 

verdigris is just malachite or hydrous copper carbonate [Cu2(CO3)2(OH)2]

 

Yeah Goldsayshi463,
chemistry is interesting to me. You seem to know a bit. Can you tell me if the bluish toning occurs under a particular circumstance that can somehow be avoided? Also can leaving a mostly stable coin in 1 % solution for a year cause the metal to degrade?

 

ok the thin layer of metal oxide can cause toning and the color of toning can be caused by the thickness in the metal oxide (until its too thick). The toning go in cycles. I actually don’t know why. Here is a pic of how it works for Morgans and their cycles:
There is a file below this that’s not supposed to be there it u can see it if u want

 

your second question is depends on the solution’s ingredients

 

I'm not sure I would leave a coin in 1% anything for a year. Water, yes...olive oil, yes...anything else, probably no. If the verdigris isn't too bad, and the coin is not an uncirculated or proof, I would brush off the loose verdigris, soak the coin overnight in distilled water a few times (1-10) followed by lightly brushing (soft toothbrush) the area and then dry it thoroughly at 200 degrees F (93 degrees C) and then store it in a flip or case in a dry area.

 

thx you for answering the question. (I don’t answer unless it’s, on a degree, specific

 

I have no idea what that means, and yes I do have a degree (although it's organic chemistry)

 

i small percentage of the things that I say don’t make sense

 

Benzotriazole is carcinogenic, I think I'll pass on this one.

 

I think you're thinking of a different chemical. The MSDS for benzotriazole says no evidence of carcinogenicity. "The MSDS says no evidence" isn't the same as "there is no risk", but apparently people have looked for this risk, and not found convincing evidence.

Still, of course, you shouldn't drink it, or splash it in your eyes, or dump it in your pond...

 

Jeff, this compound contains benzene. Benzene is a known cause of acute leukemia. Although occasionally exposure may not be a problem, over exposure is dangerous. AML is not something you want, I know from experience.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3271273/#__sec1title

 

Jesus H Chryst...IT DOES NOT CONTAIN BENZENE...NO MORE THAN TABLE SALT CONTAINS SODIUM METAL OR CHLORINE GAS!!!

 

Really? It contains a benzene nucleus.https://pubchem.ncbi.nlm.nih.gov/compound/1H-Benzotriazole