The problem: wear on bare metal hangers
Bare metal hangers that go into acid tanks and plating baths wear out in two ways. They are attacked chemically by acid and electrolyte; and because current flows through the whole hanger, unwanted plating keeps building up on it, and stripping that build-up damages the hanger further. Over time the hangers rust, thin out and deform.
The solution: plastisol coating
Plastisol is a flexible, thick PVC coating that separates the hanger's metal body from chemicals and electric current. Only the contact tips that touch the part are left uncoated.