Varnish Over Epoxy

[endoftheroad]

Im confident in my thorough application.
I recently removed my boomkin for restoration.
I purchased the materials for the restoration including West epoxy resin, clear hardner and Epifanes varnish.
Recently a concern for epoxying a boomkin was brought to my attention by a fellow Westsail 32 owner that dropping an object on my boomkin or potential stress cracking could induce moisture into the wood promoting rot and the lifting of the applied materials.
I was considering 6 coats of epoxy prior to varnishing.
Should I be concerned for the epoxy cracking due to movement of the wood?
Would it be best for only varnishing a boomkin as varnish may be more flexable than epoxy?
Shouldn't 3-6 layers of epoxy be super ridgid?

I feel very competent for my thoroughness of application of these materials and as stated in the attached West System's article reminding of the importance for being very thorough with the process.

Thank you,
endoftheroad


WEST SYSTEM | Application Techniques - Varnish over epoxy

[Reefmagnet]

Two pack paints aren't usually recommended for painting wood due to the reasons you have mentioned. Epoxy isn't UV resistant either unless pigmented so the varnish needs to protect from UV (which I think most do). Just another possible thing to be aware of. We used a two pack epoxy like varnish to do the companion way doors on a boat we had once and discovered problems over time with the moisture in the wood causing large blisters to form under the coating. I assume was because the coating didn't allow the moisture to pass through it. Varnish appears to be permeable to moisture so this doesn't happen.

Have you looked into the possibility of using an exterior floor coating? Some of these are extremely durable and will stand up for years and are easily touched up.

[endoftheroad]

Reefmagnet,
I'm aware that epoxy doesnt contain UV filters which is why it's very important for top coating with varnish high in uv filters.
But perhaps you missed something when you painted your doors?
Did you read my attached link illustrating the importance for a thorough application to prevent moisture ingress?

Varnish over epoxy in combination when done right is meant to be bullet proff but I never gave it concern for potential wood stress movement leading to the epoxy fracturing thus allowing moisture ingress.

[Reefmagnet]

Originally Posted by endoftheroad

Reefmagnet,
...
But perhaps you missed something when you painted your doors?
...

It took a couple of years for the problem to appear so I don't think it was an error with prep or application except for the fact that in the tropics, humidity is usually quite high so I'd assume moisture content in the wood would have been towards the top of the range when the coating was applied.

I'd be more inclined to go with a 2 pack polyurethane type coating and leave it at that, but I don't have a wooden boom so I don't know what the regular coating solutions are.

[endoftheroad]

I'm thinking I'm probably not going to use epoxy.

The varnish/epoxy combo is a huge debate that I've been well aware of.

Gougeon Brothers state that some paints and varnishes aren't compatable with epoxy and this attached forum conversation (link below) is all over the place.
And I've read in the past as well as in my provided link that Epifanes is a high suspect for being incompatible with epoxy.
I may just varnish the hell outta my boomkin.

Don't varnish over epoxy

[travellerw]

Meh... I did 3 layers of Epoxy (East Systems) and 7 layers of Petit varnish.. Been a couple of years and it still looks like the day I did it.. Of course the sun isn't very strong up here, but I'm betting on 20+ years of life (only exposed for 2 or 3 months a year).

[cpa]

On my last boat I did the toe rail with 3 coats of West epoxy and 8 coats of varnish. It was great up north, but as soon as I got to Florida it lasted about 3 months. I ended up stripping everything and going natural. I love exterior bright work, I like to keep enough around that I can sand and coat in 5 minutes. I then throw on a few coats every 6 weeks.

[HopCar]

I'm trying to get a little wooden boat refinished for a friend of mine. The painted parts have held up well but there is quite a bit of varnish over epoxy. It's failing and there is now a lot of bare wood now and the rest is hard to strip.

The whole job would be a lot easier if I was just dealing with varnish.

[endoftheroad]

Personally I wouldn't varnish anything that I didn't have a fabric to cover it while in the tropics (whilst on the hook or in her slip). And I still believe in a couple refresher coats each year.
When I restore an object after taking it back to bare wood, that's it, never again. Therefore you must be religious in annual maintenance.
Or semiannually for uncovered varnish in the tropics is recommended. I'll never varnish semiannual so whatever I can't/won't cover in sunbrella it stays natural or gets high quality painted.
Probably my massive unfinished cap rail will be painted.
I have to do something with it, it's getting thin from the elements.
The sun is just too damn hot on horizontal surfaces down here.

[cpa]

Originally Posted by HopCar

The whole job would be a lot easier if I was just dealing with varnish.

I remember the DAYS of sanding off the epoxy. It was a pain to say the least.

[endoftheroad]

Originally Posted by HopCar

I'm trying to get a little wooden boat refinished for a friend of mine. The painted parts have held up well but there is quite a bit of varnish over epoxy. It's failing and there is now a lot of bare wood now and the rest is hard to strip.

The whole job would be a lot easier if I was just dealing with varnish.

Hopcar,
That's what the anti epoxy guys shout about that if you don't keep high uv varnish maintenance coats on the epoxy or if the epoxy fails for reasons that are many that you will regret having to remove all that hard epoxy to start over new.
Varnish comes off easily with a heat gun.

I was planning on West resin and 207 clear hardner and varnish on my boomkin, but now, especially since I have great results with Epifanes varnish, might play conservative and just varnish.

[keepondancin]

Varnish over epoxy is a standard in some methods of wooden boat construction. However, varnish over epoxy is far from bullet proof. Any wood movement at all will allow moisture in, and eventually start breaking the bond of wood and epoxy. Constant awareness and maintainence will lengthen the time before you will need to "wood it" and start over. I like bright work, however, this year I am going to use Cetol. I know nothing is maintainence free, but I used it on some parts of my previous boat and held up quite well.

[Ketchgould]

I epoxied before I applied schooner gold. I regret it. Moisture was either in or got in and under the epoxy. Looks like a lake of separation now under a hard shell of product I need to remove.

Coamings on rhodes 32.


Christian Gould
St. Paul, MN
S/V Sea Dog
Apostle Islands Lake Superior

[endoftheroad]

Originally Posted by Ketchgould

I epoxied before I applied schooner gold. I regret it. Moisture was either in or got in and under the epoxy. Looks like a lake of separation now under a hard shell of product I need to remove.

Coamings on rhodes 32.


Christian Gould
St. Paul, MN
S/V Sea Dog
Apostle Islands Lake Superior

Christian,

Sorry bout your situation.

It can be quite an involved process for minimalizing potential failure of the project.
I'm probably going to keep on the conservative side in the future when faced with the decision for epoxy varnish combo.

Thanks