Mertons, by the way, also carries System 3.
This thread covers alot of ground on technigue and coatings.
System 3 didn't invent the 'epoxy first' routine. It was users of Smith's CPES 'penetrating sealer' that got it going in the '70s, I think. The sealer was concocted to seal DIY concrete boats and then discovered by wood workers.
But it's too easy to mix a little xylene into your laminating resin to make yer own (less expensive) sealer.
Would think that System 3's epoxy sealer is similar.
Laminating resin is a loose material and with the solvent will "penetrate' wood just as well as CPES. CPES has alcohol in the formula to chase water (found in new concrete) The present day cold weather version is a great sealer for mahogany. If it is not totally cured Steve Smith says it'll tie varnish on better. It is not often necessary to chase water in mahogany like you might have to on a ferro-cement hull.
On woods like teak and mahogany water-thin sealers like CPES don't 'penetrate' any better than any other sealer. We did experiments, if there is deeper penetration it's in microns.
Sealing with epoxy is now accepted practice for prepping wood before finishing. There are them that don't like the idea. Each to their own.
I wet out the wood with the shop epoxy mix and dry it off with rags or towels. That raises the grain. Smooth with sandpaper and douse again with the sealer, and either use it as a 'tie coat' or let it set up. Then sand for varnish. Skip the 50/50 and proceed with the normal varnish schedule, starting with thinned coats.
I like System 3's waterborne epoxy primer. I had trouble with their structural epoxy T-88. Conceptually System 3 is right-on and they are on the our side, I believe. Much more so than their steroid competitors.
Practical Sailor doesn't even know they exist!
I am sure that if you use anybody's (NO SOLVENT) 100% solids epoxy as a sealer you can put anybody else's brand finish over it. Including waterborne and housepaint. If you add your own solvent to the epoxy, you have to be sure that all of the solvent is dissipated before recoating with anything - including an epoxy product.
A recent Practical Sailor brightwork test really devalued Smith's 5 Year Clear Coat.
I have heard and read a lot of sentiment AGAINST 2-part clear finishes.
If you have to barewood to refinish you will wish you never used it. Every once in a while even old timers will take the bait and use a "BRISTOL FINISH'.
And have a hell of a time getting it off when water gets under it.
I think it's pretty well agreed that the Dutch have taken traditional varnish to the next level. Brightwork will always require maintenance. Make it easy on yourself. Getting an extra year out of a plastic finish isn't worth it. MY OPINION. Informed? I don't know.
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