In my last post, I forgot to mention two things.  First, yes you
will definately have to coat the coin with a barrier first.  With
copper this could be problematic, but necessary to prevent corrosion
from the RTV.  Since RTV vulcanizes at room temperature there is no
problem with excessive heat to the original.  Second, an absolute
necessity for this process is a vacuum.  All the air absolutely has
to be removed from the RTV in order to make an accurate copy.



Patricia McElyea
Curator of Collections
Arkansas State University Museum
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