These techniques include sandblasting and galvanizing: The sandblasting, is the operation of propelling high pressure fluid which may be water or air, or a centrifugal force with abrasive force against a high pressure surface to smooth the surface and remove contaminants. Galvanizing is an electrochemical process whereby a metal may be covered with another.
Given its complexity, those techniques require a high knowledge in chemistry and elements of specific protection. They have created lot of measures from the European directive for workers using the Sandblast are not exposed to inhalation of silica, substantially worse than in the mining industry.
I created a minigame that simulates the sandblasting and the user can interact with the web content.