Isn't this how it goes?
First, a barrier coat, just that: a very good, fairly thin 2 to 1 epoxy
--that you put on the hull after you think you completed all repairs.
It doesn't need pigment to do that job. It's a juicy seal coat for old polyester.
Imco it should be structural, not just a coating.
A laminating epoxy 'seal coat' would also fill the pores of brown fairing epoxy with the hull.
{When I did the bottom of A338 I added, I think, one coating of NSP120 PotableWater
EpoxyCoating ((WaterGard300 Solvent-FreeEpoxyPaint)) -- white epoxy, as an imitation
gel coat -- just in case bottom ever has to be sanded back in the future, the white appears
and says, enough now!} Bonus barrier coat is a 'tank' coating from epoxyproducts.com/
Next coat, if needed, are epoxy filler coats, called high build
because they have more calcium carbonate in them, which will be mostly sanded off.
This is a sanding prep coat, its only job. Its only job is to be backing for a mirror surface.
Before we rolled this white high build coat on, we used brown epoxy fairing compound
for major divits and hollows -- and endlessly faired the hull, deck or cabin before high build.
There are even more steps here to get Awlgrip ready, including a light color wash coat,
to see what was missed, and maybe one or more final high build patch coats and sanding...
if there still remain minor imperfections, pin holes, broken bubbles, fill them with white
3M painter's putty -- and with 320 or 400 rub 99% of it off.
None of this preceding stuff has to be any part of : The $$$ !@#$ Awlgrip Product System.
THEN the tie coat goes on, which IS part of the Awlgrip or LPU sequence. 'Their' epoxy coat.
It fills the pores of fillers and grabs the sanded surface. It's a very thin coating.
Can't touch the boat anymore, or get dew on it --until it's sprayed.
This would also work as prep for modern polyester gel coat. Using 'their' recommended
epoxy tie coat.
I'm no frikkin expert on this stuff -- expect to be countered -- that's what this is all about !