Protective layer forming material coating system

A method of applying a protective layer forming material, comprising:

• the first step of applying said protective layer forming material to workpieces, using:
• a coating apparatus disposed near a conveying line for successively conveying a plurality of workpieces on carriages, said coating apparatus being operable based on teaching data;
• a roller mechanism connected to said coating apparatus and having a removable roller;
• and
• a supply mechanism for supplying said protective layer forming material in a liquid form which will act as a peelable protective layer after being dried;
• the second step of removing said roller from said roller mechanism after said first step is finished;
• the third step of immersing said roller removed from said roller mechanism into a washing liquid;
• the fourth step of washing said roller immersed in said washing liquid, with said washing liquid;
• the fifth step of removing said washing liquid from said roller which has been washed with said washing liquid;
• the sixth step of drying said roller;
• and
• the seventh step of reinstalling said roller which has been dried on said roller mechanism.