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<p>[QUOTE=&quot;hontonai, post: 893514, member: 4703&quot;]The ususal method used for plating copper printed circuit boards involves applying a chemical &quot;resist&quot; substance to the area that is to be plated, then placing the board in an acidic solution to etch away the unwanted copper.&nbsp; After cleaning, the stripped board can be plated with silver, gold, or some other conductive material.</p><p><br /></p><p>Less frequently, resist is applied to the area that <i>isn&#039;t</i> to be plated, before electroplating the board.&nbsp; I suspect that that technique was used on your silver coin by carefully applying a resist to the high spots, electroplating it, and then removing the resist.&nbsp; </p><p><br /></p><p>For example, in the high school chem lab a student could have: <ul> <li>Coated it with wax</li> <li>Lightly buffed it, removing the wax from the raised areas, but leaving it in the fields</li> <li>Coated the coin with a resist substance having a higher melting point than wax</li> <li>Gently heated it enough to melt off the wax and leave the resist in place</li> <li>Electroplated the coin with gold</li> <li>Removed the resist, resulting in gold-plated fields and the original coin silver high points</li> </ul><p>Maybe that&#039;s what happened, maybe not, but that <i>is</i> a way it <i>could</i> have occurred.[/QUOTE]</p><p><br /></p>

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