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<p>[QUOTE=&quot;krispy, post: 976002, member: 19065&quot;]<b><i></i></b></p><p><b><i><font size="4"><span style="color: DarkRed">UPDATE:</span></font></i></b></p><p><b><i><font size="4"><span style="color: DarkRed"><br /></span></font></i></b></p><p><b><i></i></b> I&#039;ve followed through with an experiment to test the results of removing fingerprints from this coin in an Acetone bath. </p><p><br /></p><p>Using fresh, pure Acetone, I laid out three glass bowls with just enough Acetone to cover the coin. The coin was placed in the first dish for a period of 15 minutes and rotated (flipped over) every five minutes. Then it was moved to the second and third bowls, continually rotated at each five minute interval. Lastly the coin was rinsed in a dish of distilled water and allowed to air dry propped up in an upright position over a soft cloth.</p><p><br /></p><p>The image below compares the <b>before</b> and <b>after </b>results, of which very little removal of prints can be noted. No attempt was made to swab or massage the coin while immersed in Acetone. To repeat, this Proof coin was found in circulation and was covered in prints that had been there for an indeterminable amount of time. </p><p><br /></p><p><img src="http://i776.photobucket.com/albums/yy46/kcttck/US%20Coins%20-%20US%20MInt/2007S_PF_USD_GW_Acetone_exp_2Kpxl.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p><br /></p><p><br /></p><p>As this 2007-S Proof coin is &#039;damaged&#039; with fingerprints and has now been placed in an Acetone bath I will decide if I would like to test MS70 Coin Brightener on it or not. My experience with MS70 is limited but I have found that it removes a significant amount of dirt and surface contamination (having tested on junk silver) when worked VERY gently with a cotton swab. It is easy to over apply MS70 and it is a rather viscous (binding) substance which requires plenty of rinsing in distilled water to remove. Silver can come out overly shiny by over extending the time cleaning in MS70 and clad coins do not seem to react well to MS70 leaving them dull. I have never cleaned a Proof coin with MS70 but performed the following test on these two &#039;golden dollars&#039;:</p><p><br /></p><p>2008-P Martin Van Buren $1 with fingerprint, lightly circulated &amp; 2000-P Sac $1 well circulated with dirty spots around inside of rims.</p><p><br /></p><p><br /></p><p><b>BEFORE applying MS-70 Coin Brightener</b></p><p><br /></p><p><img src="http://i776.photobucket.com/albums/yy46/kcttck/US%20Coins%20-%20US%20MInt/20100818_BEFORE_MS70_2Kpxl.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p><br /></p><p><br /></p><p><br /></p><p><b>AFTER applying MS-70 Coin Brightener</b></p><p><b><br /></b></p><p><b></b><img src="http://i776.photobucket.com/albums/yy46/kcttck/US%20Coins%20-%20US%20MInt/20100818_AFTER_MS70_2Kpxl.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p><br /></p><p><br /></p><p>Notice that the Martin Van Buren coin has a rather noticeable fingerprint on the obverse over the portrait. Cotton swabs were used gently with a liberal application of MS70 for approximately five minutes on each coin. This removed the print and returned the lightly circulated Van Buren coin to a near flashy condition, but the Sac was not rendered so flashy, having started out more toned and worn from longer exposure in circulation. The spots around the edges (rims) of the Sac coin left noticeable exposed areas that are lighter and ring stained by the dirt or corrosion that was there before.</p><p><br /></p><p>Following my experiment with the 2007-S Proof GW Presidential golden dollar coin (above), since I had the Acetone and dishes ready for use, I soaked the following two Sac $1 coins in Acetone. Again, I sent the coins through the three stages of Acetone in separate glass dishes, rotating each coin after 5 minutes for a total of 45 minutes in Acetone followed by a rinse in distilled water and allowing the coins to air dry in an upright position. I found very little effect from the Acetone and, in-hand, perhaps the slightest intensifying of &#039;red&#039; tones in some regions of the Sac coins, particularly on the reverse. The Sac coin on the left side had several dark spots on it which were removed or rendered lighter and now appear whitish in place of the dark ones.</p><p><br /></p><p>I apologize that my camera equipment is not sophisticated enough to show all of these details, but hope this provides a general visual record of my experiments cleaning Sac and Pres dollar coins.</p><p><br /></p><p><b>SACs BEFORE Acetone bath: 0 minutes</b></p><p><br /></p><p><img src="http://i776.photobucket.com/albums/yy46/kcttck/US%20Coins%20-%20US%20MInt/SACs_BEFORE_Acetone_0m.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p><br /></p><p><br /></p><p><br /></p><p><b>SACs AFTER Acetone bath: 45 minutes</b></p><p><br /></p><p><img src="http://i776.photobucket.com/albums/yy46/kcttck/US%20Coins%20-%20US%20MInt/SACs_AFTER_Acetone_45m.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p><br /></p><p><br /></p><p>Finally, all of these coins have been placed in pvc-free flips and labeled for their cleaning and dates of treatment. In the event that three months or so down the line they have made any significant changes I will try to report back.[/QUOTE]</p><p><br /></p>

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