"James H. Nelson" wrote:
>
> Fred,
> I talked to the smooth prime people and that is what they told me
> about primer and top coat application. Even when using their top coat,
> they wanted me to put on the epoxy primer first and then a top coat.
> Believe me, I was getting tired of sanding and wanted to get it finished.
> Yes, the wet-on-wet will increase the coating thickness and
> subsequential weight. How long it will last----?? don't know.
>
>
> Jim Nelson
Thanx for clarifying that, but I thought PolyFiber's only epoxy primer
now IS UV Smooth Prime. The main purpose of the Smooth Prime is as a
UV barrier. A top coat can go directly over fiberglass, but that
usually won't work too well, but the UV issue renders it moot.
Whether or not a solvent type primer on top of Smooth Prime will
improve solvent topcoat adhesion I'd think has to be a guess. I found
a white paper on "tooth adhesion," an rather oversimplified term.
Even sandpaper grit size matters, but is coating dependent.
Re "wet-on-wet," the topcoat mfr's directions should control.
Normally it's a no-no, but if they didn't say OK, any problem would
have been quickly evident. They usually specify a wide window wherein
dry-to-touch primer need not be sanded, but after that some say you
can use SkotchBrite pads, or -- get this -- Kraft paper (brown mailing
package paper)!
Best,
Fred F.
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