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All artifacts are tagged and assigned individual identification
numbers at the time of recovery onboard the salvage vessel.
The exact DGPS co-ordinates, as well as bottom terrain, and
depth are recorded by the captain then entered into
the Corporate Database.
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Pre-conservation photos are taken of each coin, measurements
are also taken at this time and all information is recorded
in the Corporate Database.
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John Corcoran, conservator/diver, records the weight of each coin and
notes any anomalies.
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The first step of the actual conservation process is to remove
some of the hard concretion encasing the coin.
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A 10% mixture of muriatic acid and water is used to soften
and deteriorate the encrustation. The bubbles mean its working.
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There is no need to subject the delicate silver to
excessive amounts of acid, so after approximately 10
minutes in the solution the still partially encrusted
coin is rinsed in fresh water.
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Only a small section of the metal must be accessible to
attach the alligator clip.
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The coin is attached to a stainless steel alligator clip
and stainless steel wire.
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The coins are placed into the electrolysis tanks, beginning
the electrolytic cleaning process.
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The electrolysis tank consists of Soda Ash and water, with
a stainless steel plate (anode) and a low voltage current.
During the process of electrolysis hydrogen bubbles are
released and the chlorides are expelled from the metal.
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Coin Cleaning Photos: Step Two
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Electrolysis time differs for each artifact. The average
amount of time required for a silver coin is 3 to 4 days.
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At least once during the process the coins are removed from
the tank, rinsed in fresh water and the build up of concretions,
which remained on the coin when placed in electrolysis, is
removed with a soft brush.
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Coin Cleaning Process Continued:
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