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The Dangers of PVC Residue
One
of the most common and destructive residues encountered
on a coin is the plasticizer PVC. The chemical, PVC,
makes plastic softer and more pliable and is frequently
added to the make up of popular coin holders such as
flips. The problem with PVC is that under certain environmental
conditions and through the effects of time, the plasticizer
will come out of the plastic and collect on the surface
of the coin inside the PVC-laden holder. If this residue
is allowed to sit on the surface and fester long enough,
it will eat into the surface of the coin resulting
in a certain type of environmental damage known as
PVC etching. Even for new coins, PVC residue can be
bad news.
To combat the ill-effects of PVC, both NCS and NGC
recommend submitting your coins in what is referred
to as “hard” flips. Hard flips are those
that have not been treated with the plasticizer PVC
and have a harder more brittle texture than do the “soft” flips
that have PVC added to their make up. Flips are intended
as a short-term storage option. When selecting a
flip for short-term storage, such as those used to
submit your coins for professional conservation and
grading, choose those with a stiff feel that are
free of dangerous plasticizer residues. Even very
short periods of storage, such as the time for a
package to be delivered through registered mail,
can have a negative impact.
 A recent submission of modern commemorative coins
came to the attention of NCS and points out a problem
seen too often. All of the coins had been shipped
in the PVC-laden “soft” flips. In a short
time, these coins had developed the first stage of
PVC contamination. All the coins—the recent
2005 Marine Corps issues—had acquired a hazy
residue hiding the fields. This residue presents
a problem for both the coin’s long-term stability
and its ability to grade. With such a hazy PVC residue,
the coin would not be able to grade as high as it
would otherwise. Removal of the PVC residue allowed
the coin to realize its true potential.
 This 1924 S 5c is a prime example of the irreversible
damage that can happen when a PVC residue is left
on a coin’s surface. As PVC contamination advances,
the haze on the coin’s surface becomes thicker
and green in color. The thick green oily residue
is the most destructive PVC contamination. The reverse
of this coin was grossly affected by a PVC residue
that, once removed, left visible pits all over the
surface of the coin.
Even the newest and freshest coins can be adversely
affected by PVC. A PVC haze can prevent a coin from
grading out as much as it could in the short-term
and if left to become more severe could cause irreversible
damage to a coin’s surface. For information
on how to submit coins with PVC residues for professional
conservation, contact NCS Customer Service at 866-627-2646
or "NCShelp@NCScoin.com".
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Coins
of the Month
Conservation 5024124-002
Popular
with both collectors and non-collectors alike,
the Indian gold design is unusual with its devices
sunk below the fields. Unattractive spotting
was plaguing this example of a 1911 $2.50 gold
coin. Removal of both residues and what is commonly
referred to as “copper spots” with
professional conservation left this coin with
a natural appearance enhancing the beauty of
this unusual design.
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Encapsulation: 5042477-006
 The
Clark-Gruber Pike’s Peak Gold issues dated 1860
and 1861 are distinctive in the popular U.S. Territorial
Gold series for their unique design. The triangular
mountain on the obverse bears no resemblance to the
actual mountain it is identified as being. As with
many of the territorial issues, counterfeit examples
do unfortunately exist. It is important to certify
a piece as genuine even if it does have a problem that
will prevent it from encapsulation by NGC such as this
example’s improper cleaning.
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Submitter's
Corner
The NCS Submission Form
If
you have any special concerns regarding either the
conservation or encapsulation of coins you are submitting,
feel free to include notes attached to either the holders
or written in the margins of the submission form. NCS
customer service will be sure that your concerns are
considered at the appropriate point in the processing
of your submission. However, remember that NCS
reserves the right to make the final decision on the
conservation of coins.
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