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<p>[QUOTE=&quot;desertgem, post: 679058, member: 15199&quot;]<a href="http://www.cointalk.com/t60979/" class="internalLink ProxyLink" data-proxy-href="http://www.cointalk.com/t60979/">http://www.cointalk.com/t60979/</a></p><p><br /></p><p>If you read the thread above, you will note the difficulty that Boss had trying to remove a &quot;lacquer&quot; type of coating from a couple of high end Lincolns he had, namely a 1911-d, and a 1916-S. Eventually the thread got to where maybe DMSO might be a possibility, but needed proper handling. I PM-ed Boss and asked if I could see the coins, and he mailed them to me, with permission to try what I felt might work.</p><p><br /></p><p>If you look at the previous thread above, you can see the original photos he had taken.</p><p><br /></p><p>When the coins arrived, I did take the following photos that show the extent of the lacquer. Even though he had used acetone and xylene for extended periods of time, I still tried acetone for 1 hr. looking for any residue, and there was none, so he was correct in it being ineffective. </p><p>I then took these photos of what I now suspected was an acrylic mix.</p><p><br /></p><p><br /></p><p>here is the microscopic photo of the acrylic pooling around the letters on the 16-S </p><p>&nbsp;</p><p>&nbsp;<img src="http://i455.photobucket.com/albums/qq279/desertgem/glazeonrev.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p>&nbsp;</p><p><br /></p><p><br /></p><p>&nbsp;<img src="http://i455.photobucket.com/albums/qq279/desertgem/glazerev2.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p>&nbsp;</p><p>Before Boss&#039;s coins had arrived, I had found some &quot;sacrificial wheaties&quot; with the same level and type of patina, and subjected them to long periods in DMSO, to see if any deleterious change occurred. Even with 24 hrs, after removing, I tried rubbing, plastic scrubbers, toothbrushes, to see if the DMSO had softened the patina that I could damage it. Obviously I wanted no effect, and except for the slight scratches, the patina didn&#039;t change level or color, so I asked his permission to try DMSO on the coins.</p><p><br /></p><p>After several changes of DMSO over a 4 hr period, I noticed some residue on the glass containers used, and even took this photo of a </p><p>&nbsp;glob that stuck on the date after the DMSO dissolved most of it.</p><p>&nbsp;<img src="http://i455.photobucket.com/albums/qq279/desertgem/11-d-plasticondate.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p>&nbsp;</p><p>But it just flicked off with a sable brush wet with DMSO. Proof for sure there was something on the coin and had been partially removed.</p><p><br /></p><p><br /></p><p>&nbsp;<img src="http://i455.photobucket.com/albums/qq279/desertgem/11-d-plasticpushed.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p>&nbsp;</p><p>I finally did not get any more residue, but there was still some &quot;shine&quot; on the coin, and I suspect it is acrylic that is attached so firmly to the metal that physical action would have to be used to remove, and I wasn&#039;t going to do that. maybe if it was my coin , I might roll a q-tip over the surface, but not with someone else&#039;s. Scratches and wear lines were more apparent after the lacquer was removed, and I assume were the primary reason it was put there in the first place.&nbsp; Here is a photo of the 2 coins as I got ready to return them to Boss. I wished I had taken a photo of the reverses also, but I didn&#039;t.</p><p>&nbsp;</p><p>&nbsp;<img src="http://i455.photobucket.com/albums/qq279/desertgem/obverse-final.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p>&nbsp;</p><p>and viewed at a light angle to show sheen off obv.</p><p>&nbsp;<img src="http://i455.photobucket.com/albums/qq279/desertgem/obverse-at-angle.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p>&nbsp;</p><p>I think the 1911-D will tone up nicely and even with the visible scratch and tiny hairlines will be a nice coin. It appears about AU55 under the scope. The acrylic did hide a lot of problems and probably why done instead of preservation purposes. The 1916-S is AU-58/MS and still has some glossy parts where the acrylic and maybe the dellers interacted a little, but it shouldn&#039;t have, so I don&#039;t know what made the bluish shiny spots of the rev. of the 16-S. After I mailed them to Boss, I thought maybe the bluish spots is fractured acrylic, producing a fresnel effect, but I am just guessing.</p><p>&nbsp;</p><p>&nbsp;<img src="http://i455.photobucket.com/albums/qq279/desertgem/rev-1.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p>Hope I didn&#039;t screw anything up, as I think they look more natural now, but it will take some time to see. The thin film of acrylic should eventually degrade. I think they are nice coins myself.</p><p><br /></p><p>DMSO seems to be benign on the patina of copper coins. But I would recommend the clinical/vet type which is 99.9% pure. It is water and alcohol soluble, and I used 91% isopropyl alcohol from Walmart to rinse the DMSO off of the coins and then a final rinse with acetone.</p><p><br /></p><p><img src="http://i455.photobucket.com/albums/qq279/desertgem/IMG_1907.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></p><p><br /></p><p>As is the case with all chemical treatment, one should do trials before attempting on special coins. Also the acrylic seems to do a very good job of hiding scratches and tiny pits, so the resulting coin may have more blemishes than previously visible. I thank Boss for giving me the chance to test this procedure.</p><p><br /></p><p><br /></p><p>Jim[/QUOTE]</p><p><br /></p>

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