No risk conservation/restoration?
puffer
Posts: 535
Is soaking in acetone or hot water of any risk with coins? I read how the Saddle Ridge gold was restored/conserved with lots of boiling water to get the caked substance off the coins. I have used acetone a little to get artificial material off coins' surface. Wouldn't you occasionally lose the original "dirt" that some dealers speak with relish about? Isn't the alternative to send it into the restoration at PCGS with the wait times and added expense. Thoughts? Thank you!
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Comments
<< <i>No risk conservation/restoration? >>
I don' think there is any such thing as risk-free conservation/restoration.
Hot water is probably about as low-risk as you can get, though, and acetone certainly doesn't pose much risk under normal circumstances.
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<< <i>No risk conservation/restoration? >>
I don' think there is any such thing as risk-free conservation/restoration.
Hot water is probably about as low-risk as you can get, though, and acetone certainly doesn't pose much risk under normal circumstances. >>
Acetone is very commonly used to decontaminate the surface of coins as it is inert to the original surface of the coin. It will in most cases not hurt Naturally Toned (NT) coins but will take off applied surfaces. It will also help with pvc removal but not do to much for verdigris (green growth on copper mainly). Some coins do well in a light olive oil bath though some say it is a bit acidic so I would use a filtered olive oil not virgin as it has more than just oil in it. I have left Morgans in a acetone bath for a week with no damage if that helps you. The big thing is that you do not rub the surface of the coin with anything as you will get hairline scratches.
<< <i>Is soaking in acetone or hot water of any risk with coins? I read how the Saddle Ridge gold was restored/conserved with lots of boiling water to get the caked substance off the coins. I have used acetone a little to get artificial material off coins' surface. Wouldn't you occasionally lose the original "dirt" that some dealers speak with relish about? Isn't the alternative to send it into the restoration at PCGS with the wait times and added expense. Thoughts? Thank you! >>
A lot of the crusty toning on so-called original gold coins is nothing more than accumulated body oil and grime that has accumulated over the years. Acetone will strip this "toning" off the coin's surfaces and could expose hidden underlying hairlines or other problems. It could also expose some nice luster. You just don't know until after the acetone dip.
Worry is the interest you pay on a debt you may not owe.
"Paper money eventually returns to its intrinsic value---zero."----Voltaire
"Everything you say should be true, but not everything true should be said."----Voltaire
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<< <i>No risk conservation/restoration? >>
I don' think there is any such thing as risk-free conservation/restoration.
Hot water is probably about as low-risk as you can get, though, and acetone certainly doesn't pose much risk under normal circumstances. >>
This. Most damage due to conservation with water or acetone seems to come from two sources:
1. Impure solvents (water and/or acetone). Pure acetone is safe for coins, but most people don't use pure acetone (e.g. HPLC grade) as it is far more expensive than the hardware store stuff. Same with using tap water versus distilled water.
2. Improper handling during conservation, such as during the drying process.
See http://www.doubledimes.com for a free online reference for US twenty-cent pieces
It now resides in my collection as I needed the variety and in a conserved state it's worth around $750.00.
Before:
I thought it was wax based on the sellers images above and when it arrived thought I needed to have me head examined as it was a red plaster type substance. Still willing to accept the challenge instead of returning it I wrapped it up in a ball of shrink wrap & froze it in the freezer. Then shocked it with boiling distilled water which removed some of the substance and gave me an idea of what I was dealing with. Then soaked it in mineral oil for some time and later placed it still submerged in oil under a microscope. With a oil soaked wooden toothpick I gently tapped on just the red plaster. Each tap broke it up and the oil turned red and I had to wait for the red cloud of particles which dissipated to settle so I could see again. No damage was done to the token and underlying surfaces where mint red as the rest. All the verdigris growth was also removed by soaking in mineral oil. I don't use any chemicals for conservation as my motto is if I can digest it without getting ill or dying I don't use it on coins. So once finished I just patted it dry in a soft cotton cloth to fully degrease it.
Midpoint:
After:
1835 Van Nostrand & Dwight, New York, 27mm Diameter, Reeded Edge, Copper, R-2
Struck by die-sinkers Bale & Smith in NYC on a thin planchet. Although the rarity is rated a more common R-2 by Russell Rulau he only has it priced up to EF condition with no pricing above in AU or UNC. Availability wise this store card is very underrated as a R-2 since examples in any condition do not surface often.
<< <i>
<< <i>No risk conservation/restoration? >>
I don' think there is any such thing as risk-free conservation/restoration.
Hot water is probably about as low-risk as you can get, though, and acetone certainly doesn't pose much risk under normal circumstances. >>
<< <i>Broadstruck, I wonder if the stuff on that store card was sealing wax? Maybe it was used as a seal at one point. >>
ranshdow, That's what I had hoped it was on a desk while a letter was written but wasn't.
Once when I was working at a coin shop we got in a BU $20 St. that had a blob of some red, translucent substance on it. I soaked it in acetone overnight, next day nothing. Tried varnish remover, nothing. Tried paint thinner, nothing. Tried everything I could think of, nothing.
Finally decided there was nothing I could do about it, and rinsed it in hot water to remove the traces of the chemical. The red spot dissolved. For all I know it was strawbarry jam!
<< <i>Just for laughs, a true story.
Once when I was working at a coin shop we got in a BU $20 St. that had a blob of some red, translucent substance on it. I soaked it in acetone overnight, next day nothing. Tried varnish remover, nothing. Tried paint thinner, nothing. Tried everything I could think of, nothing.
Finally decided there was nothing I could do about it, and rinsed it in hot water to remove the traces of the chemical. The red spot dissolved. For all I know it was strawbarry jam!
Thanks for sharing!