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Insulating a metal sheet to render it non-conductive with spray paint

I am trying to spray paint a sheet of cold pressed steel so that it becomes insulated completely and there is no conductivity as well as infinite resistance on the outside of the metal sheet. First question is which type of spray paint (in a can that can be obtained at a local hardware store) would be the best insulator. ie. rust paint vs. plastic enamel, or whatever? Second, is it true that Black spray paint contains carbon to obtain it's pigment, thus making it slightly conductive? And third, would it be possible to paint over the spray paint with varathane with a brush, in order to make it completely non-conductive, if varathane is in fact non-conductive?

Well, that is 3 questions, but I hope you can help.

Sincerely,

Spence Lee
Spencer For Hire - Vancouver, Canada
 

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Paint layers "breathe" so that when osmotic pressure drives water under them, the paint is not blown off. I would not trust a painted finish, let alone a finish from a spray can from a hardware store, to reliably insulate. If you need insulation value, I think you need a plastisol or teflon coating.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey