Cleaning coins before storage

[GreatUncleAbe]

Hi All,

 

I've recently got a copy of "Saving Stuff" by Don Williams of the Smithsonian about preserving all kinds of stuff.

 

The section on coins is fairly short but I was wondering if you guys agree with the advice?

 

The first step involves cleaning so I guess its meant for modern coins before storage to reduce the rate of decay in storage.

 

It describes a 3-stage process of cleaning:

 

Stage 1: Wash the coin with water+triton100 anionic detergent from a squirt bottle

Stage 2: Rinse with distilled water from a squirt bottle

Stage 3: Wash with 50% acetone 50% alcohol mix from a squirt bottle

Stage 4: Rinse with distilled water

Stage 5: Place on cotton flannel to dry

Stage 6: Dry using a barely warm airstream from a hairdryer

 

Finally store the cleaned dried coin in a Mylar (polyester) folder or polyethylene zip bag (Don explains the evils of PVC very clearly).

 

I guess for modern (post-decimal?) coins where patina is not of interest then this might be ok?

 

*ducks for cover*

 

Opinions very welcome as I've never cleaned a coin before (collection still numbers less than 100 "keepers").

 

Kind Regards,

 

GreatUncleAbe

[LostDutchman]

I never clean coins

[AuldFartte]

I guess I don't understand the reason for cleaning a coin prior to storage. I wouldn't clean a coin except to remove PVC and finger oils and such using acetone.

[likes_Ikes]

i've never heard of triton100 anionic detergent before - but the rest of that sounds relatively mild except for the acetone part. I would only use acetone to remove something detrimetal on the coin (sticky dirt, residue, PVC etc.).

[Tiffibunny]

No way in heck would I clean a coin and along with AF only acetone to remove PVC or prints.

[jlueke]

Looks like none of that should damage a coin surface (not sure about copper) but not sure why they do this. Maybe the process removes any surface sulfur contamination?

[syzygy]

Hi All,

 

I've recently got a copy of "Saving Stuff" by Don Williams of the Smithsonian about preserving all kinds of stuff.

 

The section on coins is fairly short but I was wondering if you guys agree with the advice?

 

The first step involves cleaning so I guess its meant for modern coins before storage to reduce the rate of decay in storage.

 

It describes a 3-stage process of cleaning:

 

Stage 1: Wash the coin with water+triton100 anionic detergent from a squirt bottle

Stage 2: Rinse with distilled water from a squirt bottle

Stage 3: Wash with 50% acetone 50% alcohol mix from a squirt bottle

Stage 4: Rinse with distilled water

Stage 5: Place on cotton flannel to dry

Stage 6: Dry using a barely warm airstream from a hairdryer

 

Finally store the cleaned dried coin in a Mylar (polyester) folder or polyethylene zip bag (Don explains the evils of PVC very clearly).

 

I guess for modern (post-decimal?) coins where patina is not of interest then this might be ok?

 

*ducks for cover*

 

Opinions very welcome as I've never cleaned a coin before (collection still numbers less than 100 "keepers").

 

Kind Regards,

 

GreatUncleAbe

 

I see what he is getting at and it makes sense to me at some level.

 

I thought Triton-100 was a nonionic detergent, but I am too lazy to go look this up. Seems to me that the idea here is to remove deposits (that in fact may not be visible) on the coin and store it in a manner that will prevent further deposits. The detergent and the two solvents is how he removes the deposits. Since the deposits will go into solution, he wisely adds the distilled water rinses so that the contaminants are not redeposited on the surface. Consider a coin that has been in circulation for even a few weeks - it has picked up a lot of oils and finger grime etc.. These will, over time, react with the metal and chemicals in the atmosphere. If you remove the deposits and minimize contact with airborn particles you will, theoretically, maintain the coin with a minimum of change. That is basically what it looks like the plan is here. I'm not sure about the triton-100, but the ethanol and acetone are solvents that can remove surface contaminants, but they are not going to clean the coin like an acid or a wirebrush.

 

It would be nice to have a time machine and do a quick glance 50 years later and see the difference.

[bill]

My guess is that the process is designed to prevent deterioration from unseen contaminents as syzygy notes and to avoid introducing new, unknown contaminates into the storage environment (especially important in museum collections).

 

I don't (well, almost never - sometimes you get one that is just filthy with dirt and grease) clean coins and would have to think twice about doing so on a routine basis. My collection is small enough that I do look at it from time-to-time. If it were so large that parts of it might sit for years, I might be more concerned about the introduction of contaminents that I might not catch through reasonably frequent inspection.

[GreatUncleAbe]

Thanks for the opinions.

 

I'm most worried about acids from finger marks slowly corroding the coins and was looking for a way to minimise this problem.

 

Would a simple wipe with a soft cloth soak up some of the acids?

 

Do you all use cotton gloves when handling?

 

Many thanks,

[gxseries]

I can understand what the procedures are going about, but that is for museum storage purposes, where preservation is essential. But I think for most collections if you don't have valuable coins, those do not apply. Otherwise, if you believe if you have coins that have to be preserved because of it's rarity, you should send to NCS (Numismatic Conversation Services - I think) and let the experts handle. You should NEVER do try to do something experts learn over a long period of time, only to let yourself down because of your reckless act.

 

If you have fingerprints on the coin, there is nothing much you can do about it, as it is a slow acid, which eats into the coin. But it is very fresh, you might be able to do something about it. Again, if you are talking about some valuable coins here, let the experts handle it. You shouldn't.

[Ætheling]

General advice in the coin world is that coins should not be cleaned. That should be taken more as advice and not as rule though. For there are circumstances where coins are and do have to be cleaned but if your talking modern coinage (like decimals) then for the most part that should be a very seldom occurence.

 

I do however, understand you intial post and for such things as museum curation or say when the coin is of historic importance (wreck site find) and potentially deteriorating or is made of an alloy that is highly suceptible under certain environmental conditions (like if you live in Malta) then yes such proceedures would be recommended.

 

For general collecting purposes though where the coin is not an 'at risk' rarity (and few are to be honest), then it's not so much of a problem.

 

Of course if you really wanted to protect your coins from the ravages of the atmosphere then you could get them ampouled under an inert gas like Argon. But how much would that cost?

 

Better off just making sure they are handled carefully and avoid finger printing them.

[syzygy]

Thanks for the opinions.

....

Would a simple wipe with a soft cloth soak up some of the acids?

....

Many thanks,

 

It might and it might also leave wipe marks that do not look good at all.

[AuldFartte]

Would a simple wipe with a soft cloth soak up some of the acids?

 

Do you all use cotton gloves when handling?

 

Many thanks,

 

No, don't wipe a coin with anything. It will leave "hairlines" in the fields and can ruin the value rather quickly.

 

I don't use cotton gloves because, in my experience, they make it harder to handle the coin. I accidentally wrecked a nice proof once when the coin slipped and I ended up catching it while wearing the gloves. I got some real nice hairlines that way, too

[Tiffibunny]

No, don't wipe a coin with anything. It will leave "hairlines" in the fields and can ruin the value rather quickly.

 

I don't use cotton gloves because, in my experience, they make it harder to handle the coin. I accidentally wrecked a nice proof once when the coin slipped and I ended up catching it while wearing the gloves. I got some real nice hairlines that way, too

 

Poor thing. What I did once was wear one glove, dropped the dang coin and caught it with my ungloved fingers. Nice prints.

 

 

I do use gloves only when putting coins in albums, otherwise I'm an edge handler.

[Guest Sasquatch]

I wouldn't do the above unless I thought there was really something bad on the coin. I like my circulated coins with their original grime on them.

[Sir Sisu]

I wouldn't do the above unless I thought there was really something bad on the coin. I like my circulated coins with their original grime on them.

 

 

Savage!

[CABROCK8]

Seems to me the discussion is a matter of definitions.

Clean is the result of washing: a simple dip in distilled water, or a light rub with a soft cloth, or putting a rotary tool to the coin all have the effect of cleaning the coin. However, the rotary tool will certainly have an adverse effect on the surfaces of the coin, and would therefore be a no-no.

But, knowing that your 1858 whatever has been around the tracks a few times, should the coin be locked up into a slab or mylar 2x without ensuring that any surface impurities, oils and stains that are not fixed to the surface are removed as best as possible.

My bottom line:no mechanical tools, no detergents, no silver dips

Soft cotton diaper, distilled water and acetone.

Acetone dilutes light petroleum and oils (fingerprints), however, that fingerprint that has been on a surface for many years has become part of the coin surface, and this removal would need conservation followed by preservation to remove.

[just carl]

I always am amazed at just how does PVC get on to a coin. I can see some softer plastics with a very low melting point, but PVC? I have never seen PVC adhere to anything unless the ambient temperature where the PVC is located attained the melting point of 212C (413.6F). Now if a coin is present in an area where there is PVC and that temperature is reached, I would think there is a little more to worry about on the coin than PVC contamination. Also, note PVC is a stable compound that does not release gases or other elements easily. Now as to PATINA on a coin it is usually referred to as a contaminate on Copper coins. However, that too is not necessarily a by product of Sulfur as so many state on these forums due to no knowledge of chemistry. For example a greenish tone or marking on a Copper coin is usually due to exposure to Oxigen. Then as it slowly forms Cu2O and is exposed to moisture in the air and CO or CO2 the Cu2O reacts to form Copper Carbonate [CuCO3-Cu(OH)2].

Now back to cleaning a coin. DON'T DO IT. I've been collecting coins for well over 60 years and do not have any reason to ever have cleaned a coin except as an experiment. Ex-Chemist now retired. I have many coins from way back from when I started and they look just like the day I started. Most are in Whitman Classic Albums, placed in a plastic freezer type bag with as much air pushed out as possible. Other coins have been in either plastic rolls or 2x2's for many, many years. Most are kept in my basement with a large dehumidifier that goes all year if required since it is hygrometered controlled.

As to rinsing coins with all or any solutions, just a waste of time and money. I've never done it yet.

However, if I'm wrong my coins will start to self distruct in a few hundred or thousand years and if so I'll let everyone know what they look like.