Conservation Showcase: 1937 Texas 50 Cent
Posted on 1/18/2010
A recent example from our conservation laboratory.
Not only can PVC residue be unattractive, but it can also be highly damaging. PVC residue is the result of a chemical plasticizer contained in so-called soft flips. Over time, and with environmental humidity, this chemical will filter out of the plastic and deposit itself on the surface of a coin in the form of a green residue. If left on the surface, the residue can lead to corrosion on the surface of the coin.
This 1937 Texas commemorative Half Dollar was recently submitted to NCS to have this unsightly and dangerous green ooze removed from the surface. This coin was initially submitted for grading with NGC but was not certified due to this active residue on the surface. The conservators at NCS were able to remove the offensive green menace from the coin and it was able to be encapsulated by NGC after the conservation.
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