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Verdigris Removal

PostPosted: Sat Feb 02, 2013 5:34 am
by johnbrickner
No doubt this issue has been around the block several times. It never hit home 'till today. I've been working on CWRs lately. This last batch from the bank has pennys with turquoise/aquamarine (verdigris) on them ranging from a spot or edge to covered. Additonally, a bunch have the black plague. This also ranges from a spot or edge to covered. Some have both. Zinc or copper alike nothing is immune. Some have both :shock: I pulled the worst out as I dumped out the rolls and it filled an 8 oz plastic cup (imagine black pennys with pretty green).

I'm still paranoid the coppers I am pulling out will be/are infected and I dont want it to spread.

I am reminded of that old, english dubbed (done talking lips still moving,) Japanese film, "Attack of the Mushroom People" I watched as a kid. Still creeps me out, so no doubt I am over reacting. I just want to eradicate the stuff so it doesn't start growing on my walls and between my toes. :sick: I'm like washing my hands when ever I stop sorting to do something else like type here.

I have vinegar, a wiz like product, trichlorethlene (TCE), and methelethelketone (MEK) [not even going to bother checking the spelling on those] in the arsenal and I'm not afraid to use them.

However before I do, I'm going to appeal to those with more experience on this subject than I. Taking feedback, suggestions and advice on the best way to take this stuff out before I store my sorts.

I thank all that reply in advance.

Re: Verdigris Removal

PostPosted: Sat Feb 02, 2013 6:27 am
by Market Harmony
Have you considered Napalm?

You are looking at a simple solution. Here's how I would go about it:

Step 1: CLEAN - if you have a rock tumbler, then that will work well... put some abrasive soap (like LAVA soap) in with some odd shaped metal things (bent paper clips, random small stainless steel stuff, etc.) and tumble. If you don't have a tumbler, then stick the pennys in an old milk jug and shake it like a crying baby :o ... ;) Rinse, and dry.

Step 2: Vinegar and water and salt, in that order... mix a solution and put the pennies in for a bath...

Step 3: clean again... not as vigorous this time.

Step 4: (not 100% necessary) if you soak them in olive oil over a few days, then this should prevent the verdigris from spreading in the future... you might have to segregate only the worse ones before you do this.

Re: Verdigris Removal

PostPosted: Sat Feb 02, 2013 6:29 am
by Engineer
Verdigris is the rust of the copper world, and the best way to get rid of it is to grind it off. The gentlest way to do that is in a rock tumbler.

Re: Verdigris Removal

PostPosted: Sat Feb 02, 2013 7:51 am
by 68Camaro
The path I've taken is physical separation. It's a bit painful, but it also allows me to pull out all the wheats and Canadian separate. The result is bags of clean (but not cleaned) coin that will eventually be suitable fodder for numismatic purposes for anyone that cares to do so. And, then I'm left with jugs of dirty coin that I (so far) have kept, but to the side. I don't have other reason to have a rock tumbler and it hasn't jumped out as being cost-effective to capitalize for that, so the dirty coin will either be the first to be melted when the ban is lifted, or sold or traded to someone else with a volume tumbler.

Re: Verdigris Removal

PostPosted: Sat Feb 02, 2013 8:09 am
by spacemanX
for me I pull out only the wheats and dump the copper will the zinc
it in not worth the few coppers for the hassle.

on a similar note wrt CWRs I have received metal detector finds in CWRs. they are dirty and ugly but contain coppers.
I put them all in a reject bottle with my own dirty detecting coins and bent coins.

I don't refill them because I don't want a reputation of dumping bad coins and having the banks refuse my dumps.
good luck

Re: Verdigris Removal

PostPosted: Sat Feb 02, 2013 7:09 pm
by scyther
I've recently (as in, the last bag and a half I searched) started separating the "ugly Abes", as i've heard someone else here call them, and putting them in a big ziplock bag. When it's full, maybe I'll try to clean them somehow, or maybe they'll just be melted as soon as the ban's lifted (if that ever happens...).

By the way, I've found a lot of really terribly corroded zincs, and none have ever been rejected (unless the tellers just didn't tell me).So those metal detecting finds must be really bad :o

Re: Verdigris Removal

PostPosted: Sat Feb 02, 2013 7:47 pm
by Rodebaugh
Looks like another thread for the redneck rock tumbler! Not my video but I like it. :thumbup:


Re: Verdigris Removal

PostPosted: Sun Feb 03, 2013 1:49 am
by johnbrickner
The depth, breadth, and quality of information provided by RC members is the best on the planet. Bar none!
(under his breath he says "Good God, where does Doc find this stuff"???)

Thanx to all who have contributed so far. All words taken to heart, and with the immediate above to the edge of my seat cracking up. :D

Re: Verdigris Removal

PostPosted: Sun Feb 03, 2013 1:49 am
by johnbrickner
oops, site re-entering the black hole. Double posted.

Re: Verdigris Removal

PostPosted: Mon Feb 04, 2013 6:16 pm
by rickygee
And I thought a treadmill was only good for hanging clothes on the handles... :thumbup:

Re: Verdigris Removal

PostPosted: Mon Feb 04, 2013 10:45 pm
by agmoose
There is a product called verdi-gone and one called verdi-care. I believe you can find them at wizard coin supply. Made by a member at another numismatic site. It removes the verdigris without damaging the coin.

Re: Verdigris Removal

PostPosted: Fri Feb 08, 2013 10:53 am
by Dave
John, I have those chemicals where I work and the best thing I found to clean them is Acetic acid.I put them in a plastic bottle and let them sit for a couple of days, shake them up a bit . Then rinse with soap and water and dry them.

Re: Verdigris Removal

PostPosted: Fri Feb 08, 2013 1:21 pm
by rollsroy9
Hey agmoose is that something you would trust on a coin with numis value? I have a beautiful 1803 Large Cent that has a touch of verdigris on the obverse and reverse and it really bugs me. I don't plan on ever selling the coin but would love to remove this crap if its possible without lowering the grade more than the verdigris does.

Re: Verdigris Removal

PostPosted: Sat Feb 09, 2013 1:31 am
by Computer Jones
Don't soak any Cu that may have a numismatic value in Vinegar!!!

Please read the above line again until it sinks in, you will ruin the coin and end up with a pink lump of Cu worth melt value at best. A Vinegar (and Salt) solution will clean copper, but ruin any numismatic value of the coin.

Soaking Cu numismatics in olive oil for a week or so and wiping with a soft cotton cloth, (poke at the verdigris with a wooden toothpick if you must) is the least damaging way to remove verdigris. But you will have a coin that would be graded as cleaned if submitted . That lowers the value of the coin.

Live with the green blush of Verdigris and appreciate the coin, that's what happens to old copper that got near Sulfur.

Re: Verdigris Removal

PostPosted: Mon Feb 11, 2013 9:25 am
by JobIII
Computer Jones wrote:Don't soak any Cu that may have a numismatic value in Vinegar!!!

Please read the above line again until it sinks in, you will ruin the coin and end up with a pink lump of Cu worth melt value at best. A Vinegar (and Salt) solution will clean copper, but ruin any numismatic value of the coin.

Soaking Cu numismatics in olive oil for a week or so and wiping with a soft cotton cloth, (poke at the verdigris with a wooden toothpick if you must) is the least damaging way to remove verdigris. But you will have a coin that would be graded as cleaned if submitted . That lowers the value of the coin.

Live with the green blush of Verdigris and appreciate the coin, that's what happens to old copper that got near Sulfur.



Just wanted to restate this comment.

I know that every copper cent counts with this hobby / approach to investing. Even with that being true, I would strongly urge you to only do a harsh clean like this if you're sure there are absolutely no numismatic grade coins in your wash pile. That should also include BU copper cents.

Copper coins aren't very resistant to corrosion so even your pretty coppers in the bucket now could turn over the next 5 - 10 years.

Don't just go washing your hoard, unless you truly don't care about their potential numismatic value. You can't go back on this one so do think it over.

~JobIII

Re: Verdigris Removal

PostPosted: Mon Feb 11, 2013 9:01 pm
by SilverDragon72
Oh no! Not MY precious coppers!

I hope to keep mine stored without big fluctuations in temperature and humidity. Me no like the ugly green stuff!! :sick:

Re: Verdigris Removal

PostPosted: Tue Feb 12, 2013 1:13 am
by johnbrickner
This is what I now know: When doing MH's "simple solution"
you can't shake long enough nor use strong enough vinegar; Doc's redneck tumbler looks better all the time; the dump jug, reject bottle, and zip lock bag are tempting But, until I've got enough room to include an ugly abe pile . . . I'm just gonna reroll them and give them back to the bank. Major pain.

Re: Verdigris Removal

PostPosted: Tue Feb 12, 2013 10:41 pm
by Sheikh_yer_Bu'Tay
Rodebaugh wrote:Looks like another thread for the redneck rock tumbler! Not my video but I like it. :thumbup:


Doc, that is the best homemade rock tumbler I have ever seen! Genius!!!

I once heard a guy talk about soaking coins in grape seed oil to remove tarnish. Anyone hear of that?

Re: Verdigris Removal

PostPosted: Wed Feb 13, 2013 11:21 am
by agmoose
Id try the verdicare. Pm me for info and links to topics with pics of before and after. It is safe on numis as well.

Re: Verdigris Removal

PostPosted: Fri Oct 25, 2013 1:37 pm
by Numis Pam
:thumbup: Info I have been needing so commenting to move it into my posts. :mrgreen:

Re: Verdigris Removal

PostPosted: Fri Oct 25, 2013 4:25 pm
by Computer Jones
""I once heard a guy talk about soaking coins in grape seed oil to remove tarnish. Anyone hear of that?

Grape Seed Oil can be substituted for Olive Oil in the method I mention above.
Most conservators have their favorite vegetable or mineral oil (diesel oil and Jet A fuel will work).
Blends work also.
Olive and Grape Seed are the most traditional and probably oldest oils used to clean and restore Bronze.
Rape (field mustard) as well as other mustard oils are also used.

ALLWAYS wipe with a soft cotton cloth, paper products tend to scratch coins.

What ever you do, you will end up with a "cleaned" coin that usually is worth less than the coin you thought was ugly.

Re: Verdigris Removal

PostPosted: Fri Oct 25, 2013 7:40 pm
by copperhead57
I have cleaned metal detector finds by placing the coins in a peanut butter jar and adding toilet bowl cleaner containing hydrochloric acid. Then I agitate for about five minutes, and rinse. I neutralize by adding baking soda and agitating for another minute or two. Rinse again, and place coins on newspaper and allow to dry. I recommend doing this outdoors, because the acid is corrosive and may damage counters and other surfaces.

Re: Verdigris Removal

PostPosted: Sat Oct 26, 2013 10:51 am
by johnbrickner
Again, I thank all for their feedback offered. I now have the space and a good bucket to throw my ugly abes into. Have also found a local bank with a coin counter that charges around 3%. Seems to be a good price to not have to re-roll them. I'll see how long it takes to fill the bucket.

Re: Verdigris Removal

PostPosted: Wed Nov 13, 2013 12:12 pm
by Dave
I have been using acetic acid for a couple of years, I found something better, faster, and safer, citric acid. Citric acid is a powder, I put @ hundred pennies in a plastic bottle, dump in a couple of oz. of citric acid fill the bottle with hot hot water. Shake the bottle for a minute or more. Dump the dirty water and rinse and they are clean.

Re: Verdigris Removal

PostPosted: Mon Nov 18, 2013 4:22 pm
by johnbrickner
Having moved into a new place last March, I now have enough room for a bucket of uglies now about 1/5 full and that is the solution for now.