glaze coating on ceramic insulators 1

[idanbrk]

hi,

Can anyone tell me why there is a shiny coating or glaze on ceramic insulators?

thanks

 

[MintJulep]

To make them slick and slippery so that "dirt" doesn't collect as fast and is easy to clean off when it does.

"Dirt" often contains moisture, metal dust and other conductive components that can form a conductive path over the surface of the insulator.

 

[3DDave]

I think until the ceramic is fired to glass, like bone china, the material is somewhat porous. A glaze prevents water migration through the ceramic and is cheaper than glassy ceramics. Older insulators were glass.

 

[idanbrk]

thanks for the answers! very helpful