Copper Large Cent Severe Corrosion Removal & Conservation Results 1 1

[Mike Meenderink]

Many times, a particular coin's condition or eye appeal would not be in the end improved to a standard which would warrant conservation to be applied. That being said there are times when my numismatic work leads me to try things out on certain coins of this description. The coin below when acquired was very dark black. The details were badly obscured and the coin appeared to have corrosion bite on the surface. Due to this surface bite this coin would not be a "nice looking " coin when conserved. I did it anyway.  Method: Long 4-week (w/solution change) Sodium Sesquicarbonate base solution soak. I'd say better but not great...

Edited September 6 by Mike Meenderink

[Henri Charriere]

Q.A.:  I pronounce the resuscitative thoracotomy, as performed without complications, to be a complete success. Extreme emergencies call for extreme measures. You could have stood by and ignored the life-threatening chest injuries, and severe thoracic or abdominal trauma -- and did nothing, but chose to take the initiative instead and perform a surgical procedure that --

🐓  :  Wrong chart.

Q.A.: -- provided quick access to the heart and major thoracic vessels... You were saying?

🐓   :  Wrong chart!  This was a case requiring major, primarily obverse, conservation using largely untried conservation methods.

Q.A.:  Is this is the patient with the Great Rift Valley on the reverse for which there is no known cure?

🐓  :  Correct. Here's chart 137.

Q.A.:  In that case, the unproven, extended application of sodium sesquicarbonate base solution soak was a resounding success and positions this coin for top billing at its bicentennial on 2046 by which time advances will have been made to mask cleaning with a natural color and glow mimicking surface preservation to be expected for a corroded coin of that age and condition. Great work, Mike!

Edited August 18 by Henri Charriere
Die polishing.

[powermad5000]

This one. unlike your IHC from the other thread, while looks less crusty, also looks "cleaned" to me in its now current state. If I was browsing these with thoughts of purchasing one and came across this, the color would make me pass. I think it looked a more natural color when it was dark. Cool that you were able to get that crust off though.

[Mike Meenderink]

On 8/18/2024 at 10:27 PM, powermad5000 said:

This one. unlike your IHC from the other thread, while looks less crusty, also looks "cleaned" to me in its now current state. If I was browsing these with thoughts of purchasing one and came across this, the color would make me pass. I think it looked a more natural color when it was dark. Cool that you were able to get that crust off though.

Normally I wouldnt mess with this coin but it was so FUBARed I didnt care and it became a test slug. I agree its s h i t

[ldhair]

I wonder if a shorter amount of time in the solution would have left the coin with a more natural look? 

[Mike Meenderink]

On 8/20/2024 at 5:57 AM, ldhair said:

I wonder if a shorter amount of time in the solution would have left the coin with a more natural look? 

I was checking it every week and changed the solution each time as its effectiveness diminishes over time. The pics you see are from top rt first week below 2nd week below that 3rd week  (you can see some red starting to show) and then the final bright at week 4. I may have taken it out at 3 1/2 weeks and it may have still had some corrosion embedded filling the pitting which may have made a slightly better-looking surface but hey...it's just a cull that got a face lift. PS The coin has re toned now and is turning red brown. It has been 1 month since treatment. The pics show just after treatment. It looks a bit more natural as it tones but the surface is still FUBARd.

Edited August 20 by Mike Meenderink

[ldhair]

I used to have good luck helping coins like this tone back to a more natural brown color. I would just keep the coin on my desk without a holder. Each day I would pick it up and let my fingers touch all the surfaces. No rubbing. After a few months the brown was back with no signs of fingerprints. Not something I would do with a coin of much value. Not something that would straight grade but they sure looked a lot better and more natural. 

One other thing to keep in mind. When you mess with a coin like this, don't just stick it in an album when you are done. Albums can cause the coin to haze and gain colors that are not natural.    

 

 

[Mike Meenderink]

I've lightly put skin oil on it twice and it sits in a non-PVC flip (loose one) in my "semi" airtight lock box on my desk. It's going to be with me forever we will see ill post a pic of it soon. It definitely looks better as you can see the details now and the color is not to bad but...I hate the surface...lol Cheers!

Edited August 23 by Mike Meenderink

[Mike Meenderink]

Here is the coin below now after 1 month of re toning... better look but still NO BUENO. Fresh from the lab...

1 Month un stabilized storage w/ skin oil natural re toning

Edited August 23 by Mike Meenderink

[Mike Meenderink]

I may add re toning blackener to this coin soon just to even it out but I'm not rushing to it...

[RWB]

The coin has not actually been "conserved" - the surface has been cleaned and made chemically reactive. Unless this new surface is stabilized, the coin will simply degrade further (as shown by the 1-month photo, above).

"Coin conservation" means removing physically adhering material (not chemical species), and stabilizing the surface so that it does not further deteriorate through chemical means. Note that nothing will restore a coin's original surfaces.

PS: Human body oil is not chemically pure or neutral - it includes several acids. If you want to "oil" a coin, use the purest, very thin mineral oil as a protective coating. Be certain to cover all of the surface. The coin will never look "normal" again.

Edited August 24 by RWB

[VKurtB]

On 8/24/2024 at 9:48 AM, RWB said:

The coin has not actually been "conserved" - the surface has been cleaned and made chemically reactive. Unless this new surface is stabilized, the coin will simply degrade further (as shown by the 1-month photo, above).

"Coin conservation" means removing physically adhering material (not chemical species), and stabilizing the surface so that it does not further deteriorate through chemical means. Note that nothing will restore a coin's original surfaces.

PS: Human body oil is not chemically pure or neutral - it includes several acids. If you want to "oil" a coin, use the purest, very thin mineral oil as a protective coating. Be certain to cover all of the surface. The coin will never look "normal" again.

The EAC guys are not opposed to oiling, it seems. My question is, “What product is ‘very thin mineral oil’?” Eastman Kodak used to sell a product known as “Light Mineral Oil”, which was sold in a 3 fl. oz. bottle with a metal rod attached to the inside of the cap. It was used by repair techs to lubricate cameras and projectors. What is the equivalent modern product?

[J P M]

Cod liver oil was a must in the 60's ,  

[Mike Meenderink]

I replace the natural skin oil the coin started with on a coin like this. I am not concerned about this coin. It was NOT stabilized it was only cured of the verdigris. I have purposely not applied ANY stabilization beyond skin oil in an attempt to darken the coin to somewhat obscure the surface pitting. I know the coins surface will never be good. I have been doing this for a long time. I knew this coin wouldn't benefit from this it was an experiment. 

[VKurtB]

On 8/25/2024 at 7:02 PM, Mike Meenderink said:

I replace the natural skin oil the coin started with on a coin like this. I am not concerned about this coin. It was NOT stabilized it was only cured of the verdigris. I have purposely not applied ANY stabilization beyond skin oil in an attempt to darken the coin to somewhat obscure the surface pitting. I know the coins surface will never be good. I have been doing this for a long time. I knew this coin wouldn't benefit from this it was an experiment. 

Do you also stick old copper in 2x2 inch Manila envelopes and let them sit on a windowsill for a couple of years? I swear I’ve read of people doing that. I do use the Manila 2x2 envelopes, with the white cotton pouches on the inside. But I haven’t spent enough years without relocating to try the windowsill thing.

Edited August 26 by VKurtB

[Mike Meenderink]

On 8/25/2024 at 9:38 PM, VKurtB said:

Do you also stick old copper in 2x2 inch Manila envelopes and let them sit on a windowsill for a couple of years? I swear I’ve read of people doing that. I do use the Manila 2x2 envelopes, with the white cotton pouches on the inside. But I haven’t spent enough years without relocating to try the windowsill thing.

Heck anything that would produce a toning effect without adding Jax would be first then if it didn't work well, I'd just blacken/brown it. Windowsill, bag whatever.... if it works it works  I'll try it some time.

[The Neophyte Numismatist]

Maybe a Taco Bell napkin in the windowsill followed by some Blue Ribbon? 

[Henri Charriere]

There is nothing wrong with experimentation in the pursuit of knowledge as long as participating Mad Scientists test-drive their guinea Pigs on coins which all agrees are basically shot.  Nothing  tried, nothing gained.  Just make sure to conduct your tests on appropriate coins.

[VKurtB]

On 8/26/2024 at 11:11 AM, Henri Charriere said:

There is nothing wrong with experimentation in the pursuit of knowledge as long as participating Mad Scientists test-drive their guinea Pigs on coins which all agrees are basically shot.  Nothing  tried, nothing gained.  Just make sure to conduct your tests on appropriate coins.

So then no 1877 cents?