The results are in from collectors responding to conservator’s survey

Preserving Collectibles: Hobbyists queried on coin cleaning, coating, toning, patination
By , Special to Coin World
Published : 08/17/16
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Preserving Collectibles column from Aug. 29, 2016, Weekly issue of Coin World:

This month I begin reviewing the results of the coin cleaning, toning and coating survey that appeared in my Feb. 29 column.

First, I would like to thank all of the readers who took the time to respond to the survey. I appreciate your candor, comments and questions and the kind words about my column.

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Longtime readers may remember that this is the third time I have asked readers these questions. 

The first survey appeared in 1992, the second in 2006. In 1992, I received 188 responses, and in 2006, 753.  This year, the response was considerably smaller, with only 38 surveys returned. 

The small sample size makes comparisons difficult.

The purpose of the survey was to allow Coin World readers to tell me how they feel about cleaning, toning and coating pieces in their collections, topics that have always come up in any seminar that I have given. I was also interested in learning what methods/products readers were using. The following summarizes the results from the three surveys by year.

Let’s take a look at this year’s survey in more detail. These are the answers I received, with no percentages or other summary statistics. Not everyone answered all the questions, and for those who did, multiple answers were often given.

Survey Questions:

1a)  What does cleaning mean to you?


  • i)  degreasing: 12
  • ii)  removing surface dirt: 4
  • iii)  removing corrosion/tarnish:  8
  • iv)  other: 3

In every case, “other” referred to removing PVC residue/haze/green slime.

1b) Why do you clean your collection? 


  • i)  regular maintenance program: 4
  • ii)  in preparation for sale: 1
  • iii) when you notice tarnish: 3
  • iv)  other: 6

“Other” referred to: enhancing the look of the coin; removing dirt, grease and “foreign objects”; cleaning before storing to prevent damage; and revealing Mint mark or date.

1c) How do you “clean” your coins? Please include the method you use (e.g., dipping, soaking), the type of coin cleaned (e.g., silver, gold, platinum, copper and copper alloy, zinc, aluminum) and the product/recipe used.

Responses here included: commercial silver dips; grading services (e.g., Professional Coin Grading Service, Numismatic Guaranty Corp.); solvents (e.g., distilled water, acetone, 1.1.1 trichloroethane, isopropanol, xylene); hand and dishwashing soap and water; whitening toothpaste; olive oil; soaking in sudsing ammonia (for silver coins) followed by a rinse and soak in distilled water for 30 minutes; and commercial cleaning solutions other than silver dips (e.g., E*Z*EstRust Remover, Blue Ribbon Professional Coin Conditioner and Preservative). Olive oil was used to remove verdigris and to clean ancient coins. Several readers used a rose or locust thorn to remove stubborn dirt and debris.

1d) Is there a type of coin that you would never clean? If so, tell me why?

Answers included the following coins: copper; anything other than silver or gold; Mint State; Proof; from known, trusted dealers who may already have “conserved” the coin; high-value, collectible; Brilliant Uncirculated; Uncirculated; pieces with a value over $500; pieces with a value over $10; and collectible nonfiller coins to complete series.

I will continue this discussion in my next column.

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