Restoration of shipwreck silver 8 Reales 1783

[Mayadigger]

Ave!

We received a salt water-corroded 8 Reales silver coin from the wreck of the El Cazador (1783) a few days ago for our restoration service. This was our first experience with a 'shipwreck' coin and I wasn't sure where to begin...but had to start somewhere.

As seen in the before photo, we began by removing all the red encrustations by gently scraping them off with a new and very sharp scalpel blade, using a circular motion whenever possible. When doing this, it's important to use as little pressure as possible as you don't want to leave scrape marks or lines in the metal.

Once all the red blemishes were removed, we soaked the coin in a solution of Mint State cut 50% with distilled water for 24 hours, allowing the solution to gently penetrate the salt-caused encrustation.

The next step was to apply a soft-bristle brass brush (SBBB) in a battery-powered Dremel tool to the coin's surface under running water. A SBBB is an awesome tool for cleaning any encrusted coin, but the trick is to only use the very tips of the brush, just tickling the surface, rather than bearing down. In this case, the Mint State solution did it's work and the encrustations came off in a snap, no electrolysis necessary.

Just thought I should share,

Kevin