>It's a common misconception that primer will protect against rust. Primer
>is
>designed to be porous, so the top coat can penetrate and lock into it.
>It's
>primary purpose is to improve adhesion, it does little or nothing for rust
>protection. It's the top coat that locks air away from the steel, so it
>cannot
>rust.
>
>Randall
Randall is correct as usual. In one of my past lives, I inspected the epoxy
primer on the parts used to build the A-10. I had a tool that measured the
primer thickness and it had to fall within a plus/minus spec. I forget what
the spec was, but it was REALLY thin, almost transparent. I wrote up the
primer for being too thick many a time, but never wrote up too thin primer.
Too thick and the paint wouldn't stick, they said. Of course this was
aluminum alloy, and may not apply (pun intended) to steel.
John H.
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