Varnish over epoxy brightwork

Can anybody attest to the longevity / reduced maintenance / waterproofing of wood to fiberglass surfaces suggested by this article?

WEST SYSTEM | Application Techniques - Varnish over epoxy

Ahhh! I used to swear by this system!

I have done several countertops in wet areas (3-18 years), and a bathroom floor (15 years) using West System and urethanes in the house. I coated the entire Flying Dutchman, inside and out, except for the deck, using West System's special coating and spar varnish (4 years, garaged). I made a wood shower door and frame in Cedar, coated in WS and painted with Brightside Polyurethane; I made the sill for that project in Cedar and 'glassed it using WS and BP (15 years). I made a 'fan crane' for an outdoor ceiling fan which is coated out in WS and painted with latex house paint (1 Year).

The positive is that the wood structure remains dry and stable. The one place where the finish failed was under a leaking coffee pot; the epoxy cracked due to heat and water got into the finish a little before I caught it. The corners are susceptible to dings. The top is still in use.

The negatives are the extra steps to make the epoxy surface perfect w/o runs and drips, and the inevitable repair complication. You have to sand the varnish off, repair the epoxy, and revarnish. On our old Morgan 27, even though I used a 'tiller cosie', sunlight attacked the finish at the corners adjacent to the rudderhead.

I now am a little more discerning about whether I coat out in epoxy. My two later kitchen countertops are Antique Heart Pine and Teak and I use boiled linseed oil to finish. The oil accepts dings and is easily renewed.

Nice work, DHeckrotte! If we are to use this process on our exterior teak we will be using MAS Epoxy. It has no harmful VOCs, and does not require sanding between coats as it does not suffer the "amine blush" other epoxies have. Although West System's 207 Special Clear Hardener is "blush-free", too.

Here's an excellent 2-part video on the process: https://youtu.be/IqiXZrs5hvM

As far as longevity, I know folks in the NE that have been using this process for more than 15 years, and they typically only do touch ups annually (repairs notwithstanding).

West used to, may still, make an epoxy with some UV filters in it just for that application.

MurrayM said:

Can anybody attest to the longevity / reduced maintenance / waterproofing of wood to fiberglass surfaces suggested by this article?

WEST SYSTEM | Application Techniques - Varnish over epoxy

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I always varnish or paint over epoxy, at 2 coats. I find the failure is usually the calking or at joints. Very seldom the epoxy.

DHeckrotte said:

Ahhh! I used to swear by this system!...

...I now am a little more discerning about whether I coat out in epoxy. My two later kitchen countertops are Antique Heart Pine and Teak and I use boiled linseed oil to finish. The oil accepts dings and is easily renewed.

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Thanks for the info & photo's of your awesome work.

Would you be using the boiled linseed oil on outdoor wood projects, and if so, do you a) thin for the first coat, b) touch up dings as they occur, c) would it help the first coat to penetrate if the oil was 'warmed up' a bit and d) do you now prefer this to varnish over epoxy for its simplicity?

Also, thanks moonfish for the link

Murray, I don't use boiled linseed oil except indoors and out of sunlight. Remember that it's just traditional oil-based paint without pigments and opacifiers. It's the opacifier that protects the oil and the wood from sunlight. In the good old days white lead or red lead oxides were used for the opacifier; these days it's titanium dioxide. Linseed oil is also not all that proof against soapy water or continuous damp; that said, it's pretty good after it polymerizes and it does not water spot like, say, Tung oil does. I have not bothered to thin or heat the linseed oil, I do 'feed' the first coat until it quits soaking in.

By the way, don't use raw linseed oil unless you want to wait a great long time for your finish to polymerize.

The pic is an 1870s pump organ made in Guelph, Ontario, CA., with an American-made action. I restored it in about 1971 and the finish is boiled linseed oil. The finish has not been touched in 45 years.

Thanks. Dang purdy piano!

I've been sniffing around that interweb thingy for a solution to Badger's tired teak. Was leaning towards pure tung oil, but the varnish over epoxy seemed to have some advantages worth the extra effort. Will have to read up on the tung oil water spot issue.

MurrayM, I was sold on the concept of the varnish over epoxy method after moderate reading on the subject and observing allot of failing varnish (neither make me an authority). I'm convinced that many finishes fail due to sloppy/ incomplete prep along with inadequate sealing of penetrations and joints.

I choose to use a cabinet scraper to remove 90% of the old finish, then chemically strip (twice), followed by a thorough cleaning with a fine wire brush and mineral spirits. Finally the surface is flushed and brushed one last time with acetone to de-oil the surface. Some will say that wire brushing is not a good idea. However, the brushing is only removing the soft cells that would be the first to pull away and the resulting 3D surface provides more "tooth" for the epoxy.

I elected to use System 3 products and have been pleased with their performance. All of my brightwork receives the above prep followed by two coats of laminating epoxy and 6 coats of gloss spar varnish.

July will be one year out in the elements 24/7. I don't see that changing anytime soon as the limited number of 40-50' covered slips in our area have a significant waiting list. So far, so good. I certainly hope that the re-coat schedule will be measured in years...time will tell.

DHeckrotte, I second your beautiful work.

My experience

The epoxy protects the wood from turning black under failing varnish as long as joints and seams remain tight and dry. I don't know if any current epoxies that provide UV protection. That's what varnish can do when applied over epoxie. I haven't experienced dramatic improvement in the life of varnish applied over epoxy when exposed to the hot Sun of the Cal Delta. I had expected double or triple the life of varnish that was unprotected by canvas or cover. There has been some improvement , probably not enough to justify the extra work and cost.

This is a pic of an 1840's melodian (small, folding pump organ) that I restored in about 1986. The finish is Tung oil and you can see the water spots. Were I to rub it down with fine steel wool or 220grit sandpaper and wipe on another application of the Tung oil, it would look as good as it did. (I moved the melodian into the light, hoping to avoid the flash; it does not live cattywampus in front of the harpsichord.)

DHeckrotte said:

This is a pic of an 1840's melodian (small, folding pump organ) that I restored in about 1986. The finish is Tung oil and you can see the water spots. Were I to rub it down with fine steel wool or 220grit sandpaper and wipe on another application of the Tung oil, it would look as good as it did. (I moved the melodian into the light, hoping to avoid the flash; it does not live cattywampus in front of the harpsichord.)

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That's interesting, because I've read on many sites that (pure) tung oil, once it oxidizes, is pretty much waterproof...I can see how the plant pot ring could stain over time, but drops of water?

Found this interesting (not scientifically controlled) test of several epoxies, varnished and unvarnished, subjected to the elements over the coarse of a year from a sea kayak builders site;

Epoxy Test: The Epoxy Test - six epoxy types tested for UV damage

Test Results: Epoxy test results from six epoxy types

2 months: Epoxy test panel after two month

6 months: Epoxy test panel after six month

12 months: Epoxy test panel after six month

Wooden kayak designs by One Ocean Kayaks

Here's his test panel on day one facing south on his deck, varnished epoxy on the bottom and uncovered epoxy along the top. Middle was covered for the test.

Murray, this would have been finished with DuPont's Penetrating Oil Sealer and Finish #704; 29% Tung Oil, 14% Rosin Modified Phenolic Resin, 2% Driers, the remainder 55% aromatic hydrocarbons. I discovered a month ago that I still have the can(!). I've used this stuff since I was a kid. Our family were do-it-yourselfers and my dad was an engineer at DuPont, thus the prediliction for their products. And it's a nice looking oil finish, easier to handle than boiled linseed oil.

DuPont no longer makes/sells paint and this finish is now made by McClusky. A similar finish is made by Minwax.