The Proper Steps to Conservation

[BadThad]

Many collectors make the mistake of cleaning a coin when attempting to conserve it properly. The internet is full of bad suggestions and advice. So, not only is the collector who commits the sin to blame, but so are the supposed "experts" offering bad advice. The bottomline, most people should NEVER attempt to conserve their own coins. Leave conservation to the experts like NCS.

 

Nonetheless, some coins can be helped when great care is used. Also, some coins are not of sufficent value to justify paying NCS to perform a proper conservation. Unfortunately, available methods for safe home conservation are very limited. Using coin cleaners and harsh methods usually produce unacceptable results. To help out people looking to "clean" their coins, I always recommend a very conservative approach with something I call the solvent polarity ladder.

 

In chemistry (I am a chemist) we often classify solvents by a property known as polarity. Basically, it's a measure of the charge differential across the solvent molecule. The greater the charge differential, the greater the polarity, i.e. lots of positive charge on one end and lots of negative charge on the other. Another principle in chemistry is "like dissolves like". Therefore, if you have a coin surface residue that matches the polarity of the solvent, chances are high that it will be removed.

 

This is what I recommend people do. Soak the coin for 10 minutes using each of the following solvents in order. For example, start with water for 10 minutes, remove the coin and let dry. The ladder covers a wide range of polarities.

 

1) distilled or deionized water

2) acetone (do not use fingernail polish remover)

3) xylene

 

If the problem has not been resolved after trying each of these solvents, try reversing the order next, i.e. move back to acetone and then water. Sometimes residues are varied, you might have a non-polar residue on top of the polar reside....when that happens, running the reverse ladder can be effective.

 

If the problem still persists, try increasing the soak times to 24 hours in each solvent. That is about the maximum time I ever recommend soaking a coin because it's possible to produce some adverse effects on the patina with over-soaking. Also, be sure to tightly seal the soaking containers so your solvents do not evaporate!! This is VERY important because you'll just redeposit the dissolved residue back on the coin.

 

Going beyond the method I've outlined is risky and you'd better be prepared for the negative consequences. It's a common mistake to use harsh solvents recommended on the internet like catsup, lemon juice, baking soda, olive oil, etc. If you do these things, be prepared to have a cleaned coin when you done.

 

GOOD LUCK

[noow]

(thumbs u

[leeg]

Good stuff. (thumbs u

 

Acetone and Xylene will dry out copper. Here is some info to help bring copper back to life:

 

 

[BadThad]

Sorry, I could not disagree more with Burress.

 

* Xylene will NOT remove verdigris at all. Verdigris is mostly inorganic copper salts which are insoluble in organic solvent.

 

* Xylene should only be used as a soak in a sealed container with a tight fitting lid OR used as a rinse. You should NEVER apply a solvent to a coin and then let it evaporate. That entirely defeats the purpose of using the solvent. You want surface residues to dissolve into the solvent and be left IN THE SOLVENT. After soaking, remove the coin from the solvent and rinse with clean, fresh solvent. Evaporation simply allows the residues to be redeposited back onto the coin surfaces!

 

* Great care must be made if using thorns on coins! It's easy to scratch the surfaces and remove the patina, especially using the authors recommended process of dry rubbing! The proper way to use an implement such as a thorn is to do it WHILE THE COIN IS UNDER FLUID. Keep the coin under a layer of fluid and gently use an up and down tapping motion as opposed to rubbing. Only use rubbing as a last resort on extremely stubbon deposits after allowing an extended soak time (i.e. 24 hours).

 

* I never recommend an oil like Coin Care (or worse Blue Ribbon) on copper surfaces. Coin Care is nothing but napthenic mineral oil with an odorant. Using oil on coins is old school and it has many detrimental issues.

 

* Dusting with a brush after handling is almost worthless. If you want to remove surface debris after handling a coin, the best choice is an acetone rinse. For example, the author mentions saliva, a brush will simply spread it around and make it worse.