Epoxy Skimcoat

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MattGoose
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Re: Epoxy Skimcoat

Post by MattGoose »

fallguy1000 wrote: Thu Jun 09, 2022 7:15 pm Sand it all lightly say 120 grit.

Epoxy dries at a much higher mil thickness than varnish because epoxy does not really dry.

So, expectations for varnish are 1-1.5 mil and epoxy applied at a rate of 2 oz per sqyd will end up at about 2.5 mil, but when it starts to kick; you probably have some areas that are very thick and need to sand down because kicking epoxy does not lay down..while you sand; you'll know if any areas are real rough; they are probably also high relative to ideal work..
Took your advice and went back and sanded it all (or at least have started) and its looking a lot better. Didn't want to spend the time, but it quickly became clear I need to.

Lesson learned, thank you!

fallguy1000
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Re: Epoxy Skimcoat

Post by fallguy1000 »

You may have to do another sand. If you lose a batch of epoxy to gel, it really makes trouble.

I like using 1/8" nap adhesive rollers from Home Depot to wet roll epoxy. Use a bulldozer strategy. Get it all applied and then smooth and perfect it. For a 16' boat, not outside, should be easy to get on.

Use 2oz/sqyd and about 6 ounces for the roller/xtra. Running short here is bad. Better to lose a little epoxy than need to redo it 2-3 times.
My boat build is here -------->

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bklake
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Re: Epoxy Skimcoat

Post by bklake »

fallguy1000 wrote: Thu Jun 09, 2022 10:58 pm Two part finishes are way harder.
No doubt about that. Traditional varnish lasted 2 years max. The Interlux 1 part polyurethane lasted 10 years and didn't wear off where my paddle rubbed. No idea if 2 part would have lasted longer than that. I have no complaints with that kind of performance.

I didn't have to worry about mixing or wasting mixed varnish or worst of all, trying to stretch the mixed varnish because I didn't make enough. It was a good product. It disappeared shortly after I bought mine. I do remember a few bad reviews based on application problems. I didn't find it any different than traditional except it wasn't as thick. It did take 3 coats to get the thickness of 2 from traditional. They probably pulled due to poor sales. That will happen when something last a long time and doesn't need to be replaced as soon.

MattGoose
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Re: Epoxy Skimcoat

Post by MattGoose »

Want to come back and say thanks to every one for chiming in - it took a minute, but I'm really happy with the results.

I put a ton on and came back through with a foam roller to smooth it all out and ended up with almost exactly the results I was hoping for.

Need to finish the epoxy skim coats on the bottom, then time to varnish and deal with hatches and seats.

I'd like to learn more with experiences around 1 or 2 part varnishes - they suggested Epifanes, but I'd rather deal with the varnish as infrequently as reasonable. If there one type that is demonstrably easier to use, I'd like to know that too.

And what about cure times? How long do I need to wait between last coat of epoxy and first of varnish? I read something about 2 weeks, but that seems crazy.

Thank you!

TomW1
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Re: Epoxy Skimcoat

Post by TomW1 »

I highly recommennd this 2 part varnish from Interlux https://www.interlux.com/en/us/boat-pai ... ction-plus They say it lasts 3-4 times longer than a 1 part varnish and I believe them. It has the same chemistry of there Perfection boat poaints only super clear. I have had it on some of my outdoor furniture for over 6 years and it looks like new. Epihinanes is good but even on their web site they indicate touching up may be needed after a couple of years. https://www.epifanes.com/page/clear-finishes

Good luck on your selection.

Tom
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bklake
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Re: Epoxy Skimcoat

Post by bklake »

There is traditional varnish, 1 part polyurethane and 2 part poly. I have never used two part poly but I understand it is great. What your top coat must have is UV protection. The amount of UV inhibitors in proper marine varnish is much higher than hardware store spar varnish. Don't even consider going cheap here. Traditional varnish has the warm golden color that everybody expects. It is also soft and wears quickly if anything is rubbing on it. 1 part poly is tougher but may not have the color you are looking for. It is also thinner and may take a few more coats. The oak floors in my house where done with a water based poly. I don't know if it was catalyzed but it is wearing like iron. I'm using some Total Boat water based next on my kayak. I have some floor trim that I used this on. It is my test mule to see how tough this stuff is.

Epifanes is good stuff, probably the best of its kind. But, it is a traditional varnish. Most polyurethane varnishes lack the golden color that people like. It is much harder and resistant to abrasion. 2 part is hard, tough and probably a golden color. It looks like Interlux Compass Clear is the closest to what I last used. I forgot the name it had at the time but it was polyurethane based. I seem to recall it didn't have much color to it. I was pretty happy with the color of the wood with only the epoxy on it and didn't want it to be any darker. I had no problems with the traditional varnish, it just wore off anywhere anything touched it. Hatch strap points, anywhere I rested my paddle or dragged the hull on the sand getting out of the water.

Buy a really expensive, name brand, natural bristle varnish brush if you go with solvent based finish. The price of these will make you want to cry. Treat it like your first born. Yes, it makes a difference in how the varnish goes on.

Learn from your first coat how much to put on and how to blend the edges. Do NOT ever go back and try to "fix" something. It only makes it worse. Paint companies engineers and chemist predict scientifically how fast their paint and varnish should dry, that is what they publish. Theory and practice should be the same but in practice, they are not. If the sand paper clogs right away after the predicted dry time, wait. In practice, dry time is twice what they claim. Varnishing the large areas of a kayak is a little more challenging than trim work. By the last coat, you will have it down and it will look good. After each coat, it takes less sanding to get it flat for the next coat. You will see as you go. Lots of ridges and bumps on the first coat, almost perfectly flat when you lightly sand towards the end.

I started my kayak in December, hoping to launch by spring time. I finally got it in the water in late September. It was by no means perfect but it was better than I expected. I quit looking at the calendar and just enjoyed the process. 6 or 8 coats of varnish was not fun but that's what it took to look correct.

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