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Message:: [QUOTE="quarter-back, post: 1973503, member: 47022"]Detailed account of verdi-care test (long): Verdi-care trial (8/22/14 - 8/24/14)Methods I purchased one 60 ml bottle of Verdi-care from Wizard Coin Supply. The price was $15.99 plus 4.36 shipping, for a total cost of $20.35. This makes the cost of the product $0.34 cents/ml. Buying multiple bottles does not significantly reduced shipping costs per bottle (savings of ~$0.05 /per bottle for three bottles). The purchase was made on-line on 8/13/14 and the product was received on 8/21/14.  The plastic bottle was wrapped in ~two layers of bubble wrap and packed in a padded shipping envelope, shipped via USPS First-class mail, and was received in good condition.  I could find no lot number. I chose to test the product on a 1920 Straights Settlement 1 cent coin.  This coin was chosen because it is in pretty good shape (VF, on a good day - low XF), had no apparent major environmental damage but was quite encrusted with dirt, and had some light to medium greenish material showing in a number of places.  The latter appeared to be more associated with dirt build-up rather then affecting the metal per se.  In addition, this coin has a bronze composition so it should be similar to other coins on which I intend to use the product (late 19th century, early 20th century British "copper").  Finally, the coin was not terribly valuable so there was a minimal financial impact if the trial went awry. For many years I have used 70% ethanol and pointed wooden sticks to remove heavy material from circulated coins.  My goal was to remove all contaminants from the surface of coins (typically pre-1959 Lincoln cents with die varieties found while searching bulk purchases of coins). This was followed by immersion in acetone to eliminate moisture. Thus, I have extensive experience with "toothpick method" for removal of contaminant material. Initially, the coin was placed in the bottom of a 50 ml glass beaker containing ~500 µl of the product. A couple of extra drops were placed to the upward facing side to ensure complete immersion in the product.  The coin then was allowed to soak for about 22 h. Although the beaker was covered, it was not air tight and thus it is unclear how much the product may have changed due to evaporation, oxidation, etc.  I will conduct a future experiment to track weight loss over various periods of time. After soaking, the coin and as much Verdi-care as possible was transferred to the lid of a plastic quarter-sized coin tube (thanks bkozak33).  I found that working in the beaker was untenable due to the depth of the beaker, thus requiring the transfer to a shallower container. Despite the inevitable loss of product the remained in the beaker (~ 10-15 µl), transfer to the plastic lid probably was cost effective due to the reduction in surface area across which the product would spread. The "toothpicks" were made by breaking round wooden applicator sticks (~ 2mm diameter, purchased from Fisher Scientific, ~ $6.00/ 200 sticks).  In most cases the sticks break along the grain leaving two pieces, each which has a varying length of thin, rather flexible wood. This end then is trimmed to about a 45 degree angle point using scissors.  This trimming was repeated at regular intervals (~ every 20-30 seconds) to maintain a point and to eliminate contaminants the adhered to the toothpick during probing (I have found that contaminants on the toothpicks are the most common source of scratches in the surface of a coin if the sticks are not trimmed regularly). I used about 6 applicator sticks on this coin. One limitation to using wooden applicator sticks is that, after the sticks are trimmed to a new point, they wick up a significant amount of solvent (this can actually be seen quite readily under the microscope).  This wicking probably wastes about 25% of the total product used.  Finding a "toothpick" that does not absorb the solvent would significantly reduce waste. In a future test, I will examine the feasibility of using plastic toothpicks. Actual work on the coin was done using a variable magnification boom-arm dissecting microscope at about 10X magnification with ring-light illumination from directly over the coin.  I have no way to accurately measure the illumination intensity, but I was using relative low intensity lighting (about what would be achieved using a 60 W incandescent bulb at about 4 inches). Additional Verdi-care was added intermittently as needed.  Removal of surface contaminants took about 3 1/2 hours of careful work with the toothpicks.  After all of the initial work was completed, the coin was placed between multiple layers of paper napkins and a constant, relatively heavy, downward pressure was used to remove excess product. When examining the coin under moderate magnification (~20X) after removal of excess product, it was clear that a significant number of dirt particles remained scattered across the surface.  I would expect that a "rinse" in clean Verdi-care after removal of the contaminated product that remained after cleaning would greatly improve the overall outcome by removing those remaining particles.  I opted to roll a clean, dry cotton swab back and forth across the surface of the coin.  This method was relatively successful at removing remaining dirt without "wasting" additional product, and without completely removing all of the remaining Verdi-care.. Results and interpretation:[ATTACH]350596[/ATTACH]I decided to do only half of the coin rather than attempt before and after pictures with their inherent confounds of variations in lighting, angle etc.  One caveat that should be taken into account is that the un-cleaned half of the coin was subjected to immersion in Verdi-care and the handling associated with cleaning the other half of the coin.  As such, the extent of the encrusted dirt on the un-cleaned half probably was reduced slightly from the original conditions. I attempted to use only the probing method to dislodge dirt, however, at high magnification it is clear that I occasionally moved dirt grains horizontally along the surface of the coin as tiny scratches are visible at higher (25 - 40X) magnification. [ATTACH]350597[/ATTACH] [ATTACH]350598[/ATTACH]I deliberately chose a coin with a significant contaminant load. I felt that this would provide a reasonable test.  It should be noted that there was no significant copper salts build-up and no significant incursion of copper salts into the surface of the coin. I found that, in general, Verdi-care performed as advertised: it appears have solubilized and loosened the encrusting dirt. That alone, however, did not significantly improve the appearance of the coin.  Considerable additional effort was required to achieve a satisfactory outcome (note: this is not a dip type product). For those familiar with removing matrix from fossils, you will get the general idea.  This is not necessarily an indictment of the product. Rather, it is my opinion of what reasonable expectations are as to what the product can achieve un-aided. As noted above, considerable effort was necessary to achieve a satisfactory outcome.  Much of this effort, however, was directed at removing dirt from between the two strings of beading. It is likely that the effort required would have been greatly reduced on a coin with a less complex design. Verdi-care is advertised as not affecting the patina of the coin. I found this to be true.  Although there were a few small areas of "clean metal" (scratches), they could be attributed to moving dirt horizontally during the toothpick probing One limitation that I found is associated with cost/benefit ratio. In total I used about 500 µl of product to achieve the results pictured.  My estimation is that I would have used about 750-800 µl of product to clean and conserve the entire coin and the addition of a clean Verdi-care rinse would increase this amount to about 1.1 ml/ coin. This suggests that a 60 ml bottle would be sufficient to clean and conserve approximately 55 coins (assuming similar results on multiple coins, not necessarily a safe assumption) or about $0.37 cents per coin. Given the possibility of producing scratches on the surface, I would be reluctant to attempt this process on a very high value coin (others with more experience may reach different conclusions).  On the other hand, the cost per coin probably would make using the product on common date coins not cost effective. There is probably a minimum coin value at which a "break-even" point could be achieved.  However, for many collectors, coins have value beyond the pure financial aspects.  In those cases, pure cost/benefit ratios may be of little importance, and thus the cost per coin is irrelevant (I tend to fall into this category).  That having been said, at a lower cost per coin, I would be more likely to use the product more extensively, and ultimately purchase more on an absolute dollar basis. Overall, I was quite satisfied with the outcome.  The product worked as advertised.  Obviously, it is not a panacea, but then it doesn't claim to be.  Nothing is going to restore the original surfaces.  Would I use it again? - absolutely!  This was my first attempt, and I would expect the outcomes to improve with additional experience.  In the future, I may try an initial "pre-cleaning" in ethanol with dehydration in acetone, followed by a Verdi-care soak prior to the final steps of contaminant removal using Verdi-care.[/QUOTE]

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