The "japan" is not the clear coat of the machine, but the black coating on the machine. Over the japan is a clear coat.
japan |jəˈpan|
noun
a hard, dark, enamellike varnish containing asphalt, used to give a black gloss to metal objects.
• a kind of varnish in which pigments are ground, typically used to imitate lacquer on wood.
• articles made in a Japanese style, esp. when decorated with lacquer or enamellike varnish.