The E-Sylum:  Volume 9, Number 4, January 22, 2006, Article 22


Roger Burdette writes: "What the DuPont guy meant was
"glacial acetic acid." "Glacial acetic acid is called
"glacial" because its freezing point (16.7 C) is only
slightly below room temperature. In the (generally unheated)
laboratories in which the pure material was first prepared,
the acid was often found to have frozen into ice-like crystals.
The term "glacial acetic acid" is now taken to refer to pure
acetic acid (ethanoic acid) in any physical state." (Source:
Physical and Theoretical Chemistry Laboratory, Oxford

Peter Gaspar (E-Sylum subscriber #1 and professor of chemistry)
writes: "The message mentioning "galactic" acetic acid as
a solvent for Lucite was the victim of a misunderstanding.
It was presumably "glacial" acetic acid that was intended -
pure acetic acid, called "glacial" because its melting point
is near room temperature, so it often partially freezes making
little glaciers of solid acetic acid floating in the liquid.
While acetic acid is a relatively week acid - think vinegar -
I doubt that it would be a good thing to expose the surfaces
of coins to it.

I would recommend trying nail polish remover - we chemists
call it ethyl acetate - as a solvent for Lucite.  I haven't
tried it, but the structures of Lucite and ethyl acetate are
related, so it should be a good solvent for Lucite.  Warning
- ethyl acetate/nail polish remover is extremely flammable,
so its use in the quantities required would best be outdoors,
or in another very well ventilated location."

[Marc McDonald also suggested glacial acetic acid as the
proper term.  -Editor]

Dick Johnson writes: "I received an immediate reply after
publication last week of my erroneous spelling "Galactic"
in the item of removing coins from Lucite. The reply came
from lontime correspondent Benjamin Weiss Ph.D who is
Emeritus Professor of Pharmacology and Physiology at
Drexel University College of Medicine.

Ben wrote "you likely meant GLACIAL (not galactic) ACETIC
ACID." Ben's right. And this is dramatic evidence a writer
should always refer back to the original documents whenever
possible. I didn't have access to the original letter from
DuPont so I referred to something else I had written on
the same subject. Somewhere between these versions the
spelling error occurred. My apologizes.

And thanks to Ben, who, incidently has one of the best
websites in numismatics.  Not only is Ben an avid collector,
his writings on his chosen medallic topics are excellent.
His website has been mentioned in ESylum before (vol 7, no
51, article 18), it deserves a revisit:"

Mike Ellis of the Gallery Mint writes: "I came across
this problem not too long ago. In addition to coins I
also collect Indian artifacts that I find myself. When
I was much younger I also had fun embedding things in
Lucite. Of course, when I got older, I had several artifacts
in Lucite that I wanted out. Just as the DuPont representative
suggested I cut as close to the artifact as I could. I then
placed the remainder in a closed jar with acetone. Once in
a while I would take it out and whittle away the soft outer
core. It took weeks all told but it worked and my artifacts
were not harmed in the least. However, I strongly suspect
that any coin, especially copper, given this removal treatment
would result in an unnatural color. I would use it on less
valuable coins but would advise caution on more valuable
coins. Additionally, be advised, use acetone in a well
ventilated area and avoid exposure to the skin. Though I am
alive and well I highly suspect that acetone has taken
years off my life! Please be very careful with acetone."

Alan V. Weinberg writes: "Following advice I received some
years ago from an  unknown numismatist, I have had complete
success extracting coins & medals from paperweight-size
Lucite  by placing the Lucite object overnight in the
freezer, then taking it to the garage cement floor , placing
it down on top of a blanket and hitting the uncovered Lucite
directly &  sharply once or twice with a hammer . The frozen
cold Lucite shatters and you can extract the coin. I emphasize
use a blanket because sometimes the coin will go flying when
you hit the Lucite and you don't want the coin to hit the
cement and dent. Also wear some sort of glasses so Lucite
shards don't fly into your eyes.  It works!"

  Wayne Homren, Editor

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