MS70 conservation on copper - what does it do? Final summary posted!!

[Hard Times]

I started a thread to explore the issue of using MS70 on copper. In particular, there are two schools of thought. One is that it turns some copper, not all copper, but some copper, to hues of violet and blue tone by some kind of reaction of it with the surfaces of copper-bearing metal. Second, is that it removes, strips, etc. the surface patina and reveals what is underneath. Most side with the first hypothesis but none of the particularly vociferous proponents of this hypothesis can demonstrably prove this is what is happening.

Hence, when I posted a stunning large cent with very subtle underlying tone of blue on brown graded MS64 by PCGS, and one poster suggested it was AT produced by MS70, I was shocked. After listening to the explanations I realized there was not a single strong argument on either side of the issue. So I decided to do my own experiment with MS70 on copper and report the results back here. The experiment is complete, and I will present the results, discussion and conclusions. Feel free to post your own thoughts. I have not been able to do any quantitative measurements for chemical composition on the surfaces of the coins. This costs time and money. I hope to do this in the summer when I have time.

Why should the numismatic world care? Well if this is really AT, then alot of AT coins have been certified by top TPG's. However, as I work through the experiment and present it here over the next week with posts, bear in mind that in my opinion, there is no doubt that each cleaning agent for numismatic items have been vetted out by NCS, and they thus have already likely done this experiment and know more about what MS70 does than any one. NCS is likely providing the information to NGC and PCGS, so that they can make judgements on what types of toning is NT and can be graded and certified. Now the conspiracy advocates can start thinking about how the TPG's are in cahoots to screw us for money or at least are there to promote their dealers bests interests - I see this on these boards quite often in various forms of comments, but I urge you to look at the results as they progress and keep an open mind. Open, well thought out, dialogue is what we need here. The results are what they are, please read and view the following.

 

Thanks, HT

 

On the bottle:

 

MS70

"Industrial Strength"

Coin Brightener

Safe to use on;

Gold ~ Silver ~ Nickel

Copper ~ Bronze ~ Brass

Contains No Acid

Does Not Give Your Coin That "Dipped" Look

Net Contents 8 fl. oz.

 

Back side:

 

MS 70 does not change the color of your coin but does remove surface contamination and tarnish. MS 70 will allow the natural beauty of the original surface to show as bright as the day the coin left the mint.

 

Etc., but above is their key claim.

 

One each coin, I used a q-tip saturated in MS70 and carefully rolled it over the conserved areas. Except for the 1964 penny as noted below, all coins were first washed with soap and water between my thumb and forefinger, copiously rinsed with distilled water, tap dried with a towel and allowed to air for a couple hours prior to applying MS 70. After each application, the MS 70 was rinsed off by several rinses in tap water followed by distilled, then tap dried in a towel.

 

All before and after images were taken within hours of each other, identical conditions for light and camera settings.

 

First up, a control sample. This is a Morgan I have with blue brown toning, clearly not mint bag produced vibrant colors. The pre-MS70 look is on the left, the post-MS70 treatment is on the right. The composition of a Morgan is 0.900 silver, 0.100 copper, and surely many trace metals. Note the change, although the surface must be 10% copper, no toning was added to the coin by application of MS 70. Instead, surface toning has clearly been removed. This is exactly what the manufacturer claims - removal. In this case, I applied MS 70 twice, each time rolling the q-tip for over a minute. The first application there was not much change, it was the second application that finally resulted in strong removal of the toned material.

 

[rons]

I am looking forward to your presentation. I hope it can lay some of our misconceptions to rest. Thanks for taking the time and effort to do these experiments.

[Ducksoup]

I love experiments.. (involving model rocket engines, 2 liter pop bottles and a small bit of gunpowder and some adult beverages)...but mine go boom usually!

 

Looking forward to the rest of the experiment and thanks for doing this.

[PerryHall]

MS 70 does not change the color of your coin but does remove surface contamination and tarnish.

 

Sounds like a contradiction---if one removes surface contamination and tarnish, the color will most definitely change and not always for the better.

[shirohniichan]

I only used MS70 on bronze once. I bought a common date IHC off a local coin store's bid board, and I notice it had gunk covering part of "LIBERTY". I took a Q-Tip, dipped it in MS70, and rolled it across the motto to remove the dirt. It did a great job, but after I rinsed it and dropped it in acetone the obverse turned bright blue and purple. The reverse didn't change color, though.

[Coindude]

By removing the surface layer, aka tarnish, the color of the actual metal, aka coin, does not change. The tarnish or discoloration is just removed. So really, the coin color is not changed, just your perception of what color the coin was is changed.

[PerryHall]

By removing the surface layer, aka tarnish, the color of the actual metal, aka coin, does not change. The tarnish or discoloration is just removed. So really, the coin color is not changed, just your perception of what color the coin was is changed.

 

Disagree. The tarnish is chemically bonded to the surface of the coin and is a part of the coin. Removing the tarnish from the surface of the coin will change the color of the coin by exposing the raw metal under the surface layer.

[Hard Times]

Excellent discussion folks, this is what I am hoping for. I see merits in both perspectives Perry and Sam. I measured the pH of MS70 today at work with our pH meter in our lab, it helps us fingerprint what it is made of and how it works. I also was able to work out the surface mineralogy we are seeing (consulted the local ore petrologist). I will report all of this at the end of the presentation as part of the discussion.

 

More tomorrow, Best, HT

[Coindude]

By removing the surface layer, aka tarnish, the color of the actual metal, aka coin, does not change. The tarnish or discoloration is just removed. So really, the coin color is not changed, just your perception of what color the coin was is changed.

Disagree. The tarnish is chemically bonded to the surface of the coin and is a part of the coin. Removing the tarnish from the surface of the coin will change the color of the coin by exposing the raw metal under the surface layer.

Not all toning is chemically bonded. NT, that is toning that has occurred over a long period of time is whereas NT that is really AT and accelerated to make it look NT, and AT itself, is not as chemically bonded, if at all. That's why some treatments will remove toning quickly and easily when the same method will have little to no affect on a real NT coin.

[James_OldeTowne]

I was informed by a source who has been very reliable in the past, that MS70 has gone the way of Blue Ribbon, and is no longer being made. Anyone else aware of this?

[Hard Times]

By removing the surface layer, aka tarnish, the color of the actual metal, aka coin, does not change. The tarnish or discoloration is just removed. So really, the coin color is not changed, just your perception of what color the coin was is changed.

Disagree. The tarnish is chemically bonded to the surface of the coin and is a part of the coin. Removing the tarnish from the surface of the coin will change the color of the coin by exposing the raw metal under the surface layer.

Not all toning is chemically bonded. NT, that is toning that has occurred over a long period of time is whereas NT that is really AT and accelerated to make it look NT, and AT itself, is not as chemically bonded, if at all. That's why some treatments will remove toning quickly and easily when the same method will have little to no affect on a real NT coin.

 

The same goes not only for AT, or at least, quick toning versus the type that takes decades to build, but also what one would call 'patina', stay tuned....

[Hard Times]

I was informed by a source who has been very reliable in the past, that MS70 has gone the way of Blue Ribbon, and is no longer being made. Anyone else aware of this?

 

James, maybe, but I purchase my bottle a few weeks back. If you go online, lots of stores still carry it, maybe it is left over inventory?

[Hard Times]

Next up is another control sample. This one is a 2009 lincoln penny plucked from my pocket. I did so because it was completely untoned but with a spotty surface. From 1982 to present, Mr. Lincoln has been composed of a core of 0.992 zinc and 0.008 copper, with a plating of pure copper. Hence, the surfaces of these are 100% of our Cu reactive metal. Surely, if Cu reacts with MS70, with that much rich metal exposed, something would happen?

 

Well, as you can see, something did happen. Most of the spots were removed, and the surfaces became absolutely brilliant, big, even mega, flash under the light. Left is before, right is after. No new hues of blue, violet toning added. But look at how well it conserved the surfaces of this piece. Makes me (almost) want to collect lincolns..... Interestingly though, a few spots remain. I don't know if another application would help, but did not try. In the close up, note that a 'milk' spot was not removed - just to the left of the nick. I apologize for the fuzziness of the before close up, please bear with me as I post because some of these were fuzzy as I did not do a good job of screening each image before going to the conservation with MS70.

 

[BROADSTRUCK]

So far MS70 looks like it's better just to be used on pocket change.

[Conder101]

So far it looks like you've removed a film of oil from the surfaces.

[James_OldeTowne]

I was informed by a source who has been very reliable in the past, that MS70 has gone the way of Blue Ribbon, and is no longer being made. Anyone else aware of this?

James, maybe, but I purchase my bottle a few weeks back. If you go online, lots of stores still carry it, maybe it is left over inventory?

Yep, that's what I was told... that all the bottles still available on the market are leftover inventory, and it can't be replenished.

[Hard Times]

So far it looks like you've removed a film of oil from the surfaces.

 

I don't think that was oil on the morgan - suflides and oxides - i.e. tarnish was removed. But good point - the key word here is 'removed' as you noted, nothing 'reacted' and turned to blue and violet colors as many claim. Let's see what happens with other copper as we move to the next specimen in the experiment.

 

More anon, Best, HT

[BROADSTRUCK]

I don't think that was oil on the morgan - suflides and oxides - i.e. tarnish was removed. But good point - the key word here is 'removed' as you noted, nothing 'reacted' and turned to blue and violet colors as many claim. Let's see what happens with other copper as we move to the next specimen in the experiment.

 

More anon, Best, HT

 

No the Morgan lost some skin IMHO and now looks semi-dead. The post MS70 purple/blues hues will not develop on Silver nor the Zinc cent. Your further tests need to be done on pre 1983 copper cents which are hopefully just pocket change.

[Hard Times]

HI Broadstruck,

As I noted, I have done those tests and am revealing them stepwise so there can be discussion. The Morgan was a control to demonstrate what happens to silver. In hand, the Morgan still has exploding luster under the light - nice flash, I don't think it was deadened too much although the image clearly suggests it was - maybe a reflection of my lack of skill to capture the luster well(?). But no question surface tarnish was removed. For the 2009 lincoln, here was a 100% nice reactive surface of pure copper, yet there was no change to blue-violet-red tones despite having the full monty of copper to react with.

 

Next up is a 1944 penny. It is composed of 0.950 copper and 0.05 zinc. Note the before images on the left. On the obverse, which I completely conserved with MS70, before the application, there was a rich ocre-brown patina comvering the surface. 'WE' had green verdigris at the top and between the rim and 'W'. The brown coloration varied in hues from location to location. The portrait of old Abe seem to have a hint of a bluish-violetish tinge to it around the edges, and there were hints of other red-violet-blue areas elsewhere. Luster is subdued. Back side, very grungy, not as obvious of areas of colors other than brown hues.

 

Now let's look at the conserved images on the right. On the obverse, the luster is now much greater as show from the greater reflectivity of the surfaces under the light. The coin now has a cartwheel flash when rotating under the light. Look around the edges of old Abe. Real, honest to goodness no questions asked, blue-violet-red toning apparent in the same locations as it was hinted at before conservation. Look at 'IN'. Same thing. Darker areas on the unconserved coin now come out to have different colors than the brown areas.

 

On the reverse I tried to only conserve one side. Note it was less subdued for blue-violet-red toning than the obverse was before conservation, and now, after, it still is But where lots of grunge was present, now there are dark and brown splotchy surfaces after conservation. No blue-violet-red. What is very clear from the after image of the reverse where one can see the center area of the coin that still has its original surface and was not conserved with MS70, in the areas that were conserved, the brown patina was removed and the underlying surface revealed, with no apparent change in color to blue-violet-red.

 

Conclusion, MS70 removed the surface layers of brown patina, verdigris and grunge. Only in areas where hints of blue-violet-red were present, did areas of blue-violet-red become revealed as patina and grunge were removed. Were these areas acting as focal zones of reaction with MS70 or were they areas where this toning was already present and instead was just exposed by conservation?

 

Stay tuned, more to come that will add evidence on which occurred.

 

[Hard Times]

Continuing down the path, here are a series of lincoln pics. You can tell where MS70 was applied as the brown patina disappears. As in the previous images, blue-violet-red toning is only observed where there were hits of something not completely brown in the before conservation images to the left. In some areas where original mint orange was present, mint orange was still present after conservation - little or no reaction to pure copper. Look at the close ups and see what you think. I will get to some more telling images in the next post.

 

 

 

 

 

[rons]

Great info with terrific photos. Thanks for sharing your research with us. I never noticed the plugged 9 on the 57d Lincoln before

[MarkFeld]

From what I have been told, the most noticeable changes are likely to occur on RB (as opposed to RD or BN) copper coins which are treated with MS70.

[Hard Times]

Stay tuned Mark, more coming, some that might be considered 'RB'. But look at the lack of affect on a completely untoned, 100% copper surface above for the 2009 cent. How do you explain this if 'change' versus 'removal' is what is going on here? Then the next question is, why would an RB behave differently? It could be possible if there is something specific on the surface that the MS70 would react with, but then why would brown copper coins, but with some orange-red surface area, like some of the lincolns above, not react pervasively? All good questions and observations. I will try to post the next comment and image tomorrow. At the end of all of my photos, I will provide a summary with respect to Cu oxide and sulfide mineralogy, the PH test we did, and speculations on what MS70 is composed of based on the PH, which is a good fingerprint of chemical composition.

 

Thanks, HT

[mhomei]

that is awesome, and thanks for the experiments and the pics..very very

nice!!!

[Hard Times]

Here is the next one, three more to show after this, including two coppers from the 19th century. This is also a 2009 lincoln plucked from circulation. 100% copper surface layer. This one is a key piece of the puzzle about what MS70 is doing. So let's look at the before image. It has a brown patina with an RB look where protected areas are untoned but clearly now blue-violet-red coloration prior to conservation. It also has some dark gray spots. The close up shows that there are some lighter gray spots also, suggesting two types of gray coloration.

 

Now let's look at the conserved coin to the right. Immediately, one sees that three things have happened/did not happen. First, the dark gray patinated areas now show the classic blue-violet-red coming out. Second, the light gray spots/streaks? They are now sliver in color, actually zinc in color. So what we are seeing in the unconserved image to the left is a light gray patina forming over the exposed zinc. If one removed the pervasive light gray patina by conservation, the zinc is exposed, and it appears that the darker gray spots and areas underlying the light gray patina were in fact the vibrant toned areas - is this a reaction to MS70? Finally, what did not happen. Protected original red copper areas again did not change color, they remained the same.

 

As we go through these, note also that in almost all cases, the lighter brown patinated areas in the coins tend to become darker brown patinated after conservation. This is not a play of the image - all before and after were taken under identical lighting and camera setting on the same day - before images taken, conservation, after images taken, in a matter of a couple hours.

 

Take a hard look and make your own conclusions. The close-ups are worth study.

 

[relicsncoins]

If I had to draw a conclusion based on data provided to this point, I would guess that MS70 is reacting with zinc or zinc oxide and not copper. My theory is that on the first test lincoln with the zinc core and 100% copper plating is that no zinc is exposed on the surace of the coin and therefor the MS70 did not cause the coin to change color. However, on an alloyed coin with copper and zinc, there are both zinc and copper atoms on the surface of the coin.

 

This would make sense, as even though copper is a reactive metal, zinc is highly reactive, and in fact is so reactive that it is used as a corrosion preventer in the form of zinc annodes on other metals.

 

Edit to add:

 

After thinking about zinc and copper, something sounded familiar with it from high school chemistry days.(more than 20 years ago.) I vagly remember an experiment using zinc and copper sulfide solution. I remember the copper sulfide solution being blue. There was some kind of reaction between the zinc and copper sulfide. This MS70 reaction may have something to do with this basic chemistry experiment............or not.

[grip]

If I had to draw a conclusion based on data provided to this point, I would guess that MS70 is reacting with zinc or zinc oxide and not copper. My theory is that on the first test lincoln with the zinc core and 100% copper plating is that no zinc is exposed on the surace of the coin and therefor the MS70 did not cause the coin to change color. However, on an alloyed coin with copper and zinc, there are both zinc and copper atoms on the surface of the coin.

 

This would make sense, as even though copper is a reactive metal, zinc is highly reactive, and in fact is so reactive that it is used as a corrosion preventer in the form of zinc annodes on other metals.

 

I think your on to something with the conclusion it's the zinc interacting with the MS 70 and giving it the color.

[erwindoc]

I would like to see your results on an impaired proof(or non-impaired for that matter). Toned or not, with the delicate surfaces, especially the fields and cameo surfaces one would see damage if there would be any. I have played with the stuff on some impaired proof kennedy's I found roll searching and had amazing results.

 

This has been a great post, keep it going!

[Hard Times]

I would love to have some copper proofs to sacrifice but I don't, but good idea erwin.

 

Here is the last lincoln, after this I will post the two half cents I used MS70 on (don't worry, they were heavily degraded and I bought them on ebay before I knew that were dishonest dealers that sold raw coins there and did not reveal they were heavily cleaned etc.). This lincoln was selected solely because it already had blue-violet-red toning visible beneath a brown patina. I picked it out of my pocket change because it looked like this. As will all of the others, the only thing that I did to it after selecting it is washing it with soap and water between my thumb and index finger, with many rinses in distilled water and then patted dry with a towel.

 

Take a look. Again remember, the surface is 100% copper plate. In this case, there are digs exposing zinc core, and in the close up you can see that where these are, the conserved image shows dark gray color. In the other areas in the before conservation images on the left, there is blue-violet-red tone and brown patina, with some original copper-red in the protected areas. Now take a look on the right images after conservation by MS70. The blue-violet-red has now come out strongly as it appears to me that brown patina has been removed. The color of dark gray in the digs is now more prominent as if patina/tone was removed. One can also see that the protected areas with original copper-red surface has not changed, it is still the same.

 

[Hard Times]

Okay now to the 'old' copper. First up is an 1854 half cent. I bought this from a less than ethical frosty ebay seller in 2005 when I was naive about buying raw on ebay, I was also new to understanding what a cleaned coin was so it took me some time to understand this coin was not gradeable at a top TPG. The listing said this was a MS64 half cent, in reality is ws a harshly cleaned half cent. There are linear lines in the fields from an old cleaning that impeded the luster. Anyway, so I used it here to test with MS70. As in previous posts, the before conservation are left images, the after are on the right.

 

So take a look at the images. The conserved images clearly show the blue toning that MS70 conservation is known for. Notice in the unconserved obverse image, that in the field behind Miss Liberty's hair the hairlines are not really noticeable, whereas in the conserved image, they come out very well. The lights were placed in the same orientation for both photos. In hand, I can say that all hairlines from the old cleaning are more apparent in the conserved coin than they were before using MS70. Note in the close ups that the blue toning for the most part appears to correlate with with areas of dark gray on the pre-conserved images. Areas that had brown patina/toning, remained brown after using MS70. Note even a star in the close up that is brown with a dark gray around in the fields, remained brown after conservation and the dark gray in the fields are now blue.

 

 

 

Now here is the second sacrificed half cent. This one was also bought from the same frosty ebay seller. The image on ebay showed a half cent with brown surfaces, but when the coin arrived, it was a teal/green uniform color and when under the light, the surfaces gave a uniform reflection rather than a cartwheel luster when rotating under the light - I interpret now after learning, that this coin was likely over dipped in an acid bath. So a couple years ago, I put this coin in a Wayte Raymond old green half cent album and heated it under the lamp for a few weeks. What you see on the left is the toning that was obtained by doing so, the original green/teal surfaces disappeared presumably either reacted out or was coated into the new toning that appeared from the heating in the Raymond album. On the obverse, I used MS70 on the whole coin, on the reverse, just a couple dabs in different locations. Result - the obverse now shows the original green/teal (not blue like the 1854 or blue-violet-red like the others in earlier posts) of the coin when I got it from the ebay seller. The reverse has the same color where MS70 was applied, and it appears to be exposed only where the new tone is stripped off.

 

I interpret this to show that MS70 did not react with this 1828 half cent copper surfaces, but instead stripped off the new toning imparted to the surfaces from my Raymond toning experiment.

 

My next post, when I have time, I will make a final summary and list our results of the pH test for MS70 which helps us know what it is, and also discuss the results in light of copper oxides, sulfides and other potential products of exposing copper to our atmosphere and chemicals. Then I will give my best guess as to whether MS70 is reacting to give toning to copper surfaces, or instead is stripping off surface layers.

 

Thanks, HT