Définition

• Ultrasonic Cleaning.  Cleaning by solution set to vibrating at a very high frequency. The process is noted for nonabrasive cleaning that is ideal for coins and medals (as well as jewelry, other small objects that can be suspended within the solution container of the vibrating machine). In from two to five seconds particles of the smallest size are removed by caviation (collapsing vacuum bubbles) waves from the tiniest of crevices in the detail or relief. It is also useful in the finishing department as all forms of unwanted particles from prior manufacturing steps – filing, buffing, polishing – can be quickly removed before a final finish is applied. Commercial solutions are employed suitable for the type of metal and the object. The dislodged particles fall to the bottom of the container and the solution needs to be replaced according to instructions accompanying the machine.

  excerpted with permission from

  An Encyclopedia of Coin and Medal Technology

  For Artists, Makers, Collectors and Curators

  COMPILED AND WRITTEN BY D. WAYNE JOHNSON

  Roger W. Burdette, Editor

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