polishing

The polishing includes several techniques that consist in polish (make it shiny) or satin finish (matt render) of metallic objects by friction of different materials (abrasive, cloth, etc...).

Located after the various preparation techniques (grinding, felting or softening) and before finishing techniques (satin or brightening), it consists of polishing the pieces using fabric discs (linen, cotton or other) impregnated with more or less abrasive paste and mounted on rotatable reels at different speeds depending on the material of the workpiece.

Under the effect of the pressure, the resulting heat can very briefly locally reach very high temperatures. The metal seems then to "flow" (professionals use the term "creep" of the material). The choice and sequence of abrasives (grain size) is very important to get a perfect surface polished.

 

source : www.cpih.ch/fr/m6/Doc_a_tel/fichiers/BrochurePolisseur08.pdf