Coin Maintenance

I use acetone on every coin prior to submission, so also that, but mostly you're just seeing differences in lighting and color balance. The only shots I took with my regular photography setup were the after pics on the 1868.

 

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IME, w0hen I see "blue" = acetone but I've gotten this exact color/surface/excellent result w/MS-70. Nevertheless, it does not mater how /what is done as long as the coins come out as nice as yours did. You can give us all lessons

 

BTW, what is MS-70?

 

A coin cleaner, and pre-dip. Very useful for coin conservation and as far as I know used at each major TPGS. Learn to use it correctly and you'll swear by it (in spite of what you'll read on CT). Unfortunately, we think they changed the formula "slightly" around 2001. The color changed (and still does from batch to batch). Betterbilt claimed the formula did not change but IME the product worked much better in the past no matter how good it is today. One conservation lab I've been in keeps the old stuff "locked away" for the director's use on really rare stuff. One day, the old stuff will be as rare as "Blue Ribbon" and "Trike"

Betterbilt Chemicals.

 

Sorry, as a chemist, I meant what was in it...I looked it up...holy crap, potassium hydroxide. If you got this on your skin, it would dissolve it. Similar to lye, but stronger. Be careful with it! http://www.translinesupply.com/PDF/MDSSHEETS/MS707530.MSDS.pdf

 

Yep, it will take your fingerprints right off - I know . That's what Q-tips, and tongs are for. That is also why it is a faster, more effective "cleaner" than VC.

 

Actually I believe lye (Sodium Hydroxide) is more corrosive (stronger base) than Potassium Hydroxide. But even more important is the concentration of the base. Sure concentrated lye will eat your skin off. But diluted it can be quite safe. Lye is used in the making of pretzels and bagels, noodles, chemical peeling of fruits and vegetables, processing cocoa, and chocolate.

 

A quick search gives me contradictory information, one site says KOH is stronger and another says NaOH is stronger. You are right, concentration plays a key role. NaOH is used to take the skin off of corn and make hominy, while the residual NaOH in lye soap just makes it a good cleaner and usually won't take but half your skin off. : - ) Either one is strong and I don't think a dilute solution is used for coin cleaning.

 

It is not. Full strength all the way, every day, makes the film and crud go away.

 

NOTE: WARNING VERY IMPORTANT WARNING

There are many cases where you do not want to touch a copper or silver coin with MS-70! Only experience w/the product will guide you and SOMETIMES that does no good. For example: MS-70 can make the stains on some silver coins more pronounced and If used on the wrong ED on a copper coin it will remove the ED and turn the area shades of red!

 

I was being facetious. I have no clue what the mods think. They're scarry

 

pKb of KOH is about twice that of NaOH.

Both are extremely strong bases, especially as the ionic strength increases. In my experience brief skin exposure to strong bases isn't really that bad as long as you rinse it off immediately. It turns the top few layers of skin into soap but it's not what I'd call an "emergency". The eye is a different story.

On another note, I used to regularly prepare saturated sodium hydroxide solution for lab work.....arrrrggggggg. I hated the stuff, very high respect for it! It concerned me more than mineral acids.

 

...and smooth as glass. Soon some entrepreneur will make MS-70 smell better and sell it as a beauty product to women!

 

CT members may wish to check on this. AFAIK, unless the submitter puts PLEASE CONSERVE on the submission form as I have seen done by one TPGS during the recent FUN show, the TPGS better not touch a coin (even though it may improve the eye appeal) or they could get accused of a switch!

I heard/read a story in a grading seminar (long ago) that happened at the old ANACS in DC. Someone sent a 1936 Proof Lincoln cent in for certification. The collector bought the coin at some auction where it was described as being a "Gem" Proof with "beautiful sea-green toning." When the coin got to ANACS, the "sea-green' toning turned out to be LIQUID PVC (?) contamination . The inside of the plastic flip and the coin was WET! ANACS removed the stuff (I think they used acetone), graded the coin and returned it. Soon after, the owner claimed they had switched his coin
and demanded restitution. I believe ANA paid his claim and kept the coin. Lesson learned?

This is absolutely true! Some people (the uninformed) should not play with guns, knives, or chemicals. Nevertheless, the experienced professionals at NCS and ICG (two services I can speak of with certitude) know how to easily turn the color back to "original" in seconds.

This is a great tip! You should RARELY dip a clad coin. MS-70 is first choice.

 

MS70 has its' place, used carefully, but as the gist of the explanations of it indicate, it is nearer the edge of being more intrusive than necessary. Only patience stands between the conservator of a coin and success with milder methods. That does not mean a collector learning to conserve should not become expert in its' use; quite the opposite. On the (mandatory, IMO) scale of relative intrusion - and therefore greater risk to the coin - MS70 could reduce a process from three lesser steps to a single step, lowering the chances of a mistake.

 

MY BAD...They actually said they did this? NCS was not even around back then.

Actually, you are 100% correct. I FORGOT. Mike Fazzari, told a class how the idea for NCS was developed when he went into a cleaning closet at NGC and took some copper spots off a gold coin (which then went up a grade). That was sometime after 2000.

Still, I'll bet they said this to get more business and I'll also bet the owners of the coins were "big" customers who knew. I've been told that some large volume customers have given a "blanket" permission for any conservation that was "free" and could improve the coin.

 

@Insider (if I'm not wasting too much of your time)

What took the copper spots off the gold? I've seen some spotty Albanian gold coins in a slab where poor Zog looked like he had the pox. Seems like (if it were me) the coin should have had the spots removed as at least one of the coins was a pretty nice coin otherwise. Except for the pox.

(Assuming this is not proprietary information).

Or, if spots are 'conserved', do they come back?

edited to add--found a screen shot. This is in an MS-65 PCGS slab according to the auction listing.

 

Spots can temporarily be removed by any normal conservation method (a dip, for example). However, because the spots are often due to inconsistencies in the alloy, the can sometimes return. They are called "copper spots" because these are localized areas of higher copper concentration - gold does not react with much, but copper reacts with just about everything. The reddish-orange spots are where the copper in the alloy is reacting. If you don't completely remove the higher copper areas (which would leave a pitted coin), the copper spots may return.