Choosing a Marine Varnish

Varnishes have been used to protect and maintain woods on*trawlers for many, many years.* History indicates that varnishes used in the 1700s are very similar to those used today.* The coatings allow for the attractiveness of the teak to be viewed while offering protection from rain and sun.* The luster attained after cautious application will deviate from a soft patina to a high gloss finish analogous to fine furniture.

Presuming you wish to protect and embellish your*trawler's exterior teak, how do you select among the astounding diversity of finishes? Recognizing full well that this is as big a deal as arguing the differences between single and twin engines, I nevertheless provide the accompanying observations.

What is a Varnish

A varnish is a liquid finish commonly used to treat wood.* Its principal ingredients are*oils. resins, solvents, dryers and perhaps ultra-violet additives.* The components are used in different quantities to provide the best appearance and protection.

Varnish

Spar or marine varnish is a complicated product. By changing the ratios of the components and by blending ultra-violet inhibitors and other secret ingredients, producers make varnishes with widely varied features. Varnishes can have a gloss or matte visual aspect, can be produced to be extremely hard for walked-on surfaces and can vary in color.

The two most routine varieties of varnishes are traditional varnishes made with tung oil and newer polyurethane coatings. Natural tung oil varnishes are great for interior or exterior use and offer the classic golden teak appearance. Oil modified polyurethanes tend to be more clear, allowing the color of the wood to shine through.

Recent varnishes, provide better durability in the harshest of environments such as the hot, tropical sunlight. Wood moves, since it is a formerly living thing, it enlarges and compresses with even small fluctuations in temperature and humidity. Premium varnishes cope with this unstable wood using high quality*oils and resins and a higher percentage of solid components, providing a longer lasting, more elastic coating with a greater gloss.*

The number of coats is everything. Six to ten coats is normally required to get a superior look.* A sound base coat, annually cared-for with maintenance coats, will give the ultimate in appearance, length of service and protection.* Despite the original effort (up to 10 coats are common) nothing looks better on a trawler's handrail than exterior brightwork finished with gloss varnish.

Interluxs Original 90 is one of many brands of traditional spar varnishes on the market.

Synthetic Teak Finishes

These coatings gained popularity with cruisers in the tropics looking for ultra-violet resistant low-maintenance brightwork. Developed for ease of application, these products have remarkable durability for exterior use, are easy to apply and look*pretty good.*Some varnishes such as Interlux Goldspar and Schooner are produced with no pigment so the teaks beauty is protected. Full gloss and depth vs. convenience is the tradeoff with these finishes, but simplicity and labor savings can more than compensate. Applying synthetic finishes is akin to teak oil, where you can lay it immediately over sanded, clean teak.

Cetol is a synthetic and comes in four varieties, with the new Natural allowing for a more golden color resembling the real look of raw teak.* Overcoat any of the other pigmented Cetol finishes with the Gloss for a high gloss exterior finish.

I know of one professional that applies Cetol entirely and his work is fantastic.** I use this product myself on my trawler.


Two Part Teak Urethane Finishes

Another product to show up recently in the cruising world are the urethane two-part finishes.* Fashioned to replace traditional varnishes, these products have made a mark in the yachting community.* Their producers produced these finishes to survive in tropical conditions for years at the time.** One maker, C Tech Marine, boasts that its product Bristol Finish is utilized on numerous cruise ships, certifying to its beauty and longevity.

Oils

Oils typically hold the original look and texture of the wood more than the other finishes because they penetrate deeply into the teak fibers and do not create as much of a surface coating.*Oils are available in colors ranking from water clear to gold to dark brown. As with all teak finish, many coats generally result in a much more uniform finish and longer length of service. We find oil to be the simplest to utilize, since surface blemishes are not as apparent in the final outcome. This does not mean, notwithstanding, that applying four coats of wood oil on dirty teak will develop a Bristol finish. You will also see that oils thin consistency makes masking areas to protect surrounding gel coat and painted surfaces about as important with oil as with varnish. Clean, sanded teak with several coats of oil will give your teak 3-6 months of beauty and protection.

Tung oil is used frequently for teak applications.

Don't forget Armada. It has all of the advantages of Cetol and looks more like varnish.....nor orangy opaqueness!!! It is much clearer.

We switched to Bristol about ten years ago when my wife first read about it and based on our experience so far we will never use varnish again (except over vinyl lettering since Bristol tends to soften and "eat" it).

Marin,

Is Bristol epoxie?

Eric Henning

No, Bristol is a two-part urethane finish.* http://www.bristolfinish.com/* It comes in two varieties, gloss and satin.* The gloss is meant for exterior use and is extremely UV resistant.

Some people have trouble using it because when the two parts--- the urethane base and the catalyst--- are mixed together the finish is very thin, almost like diesel fuel.* If it's applied too heavily to anything other than a level surface it can sag and run.* So the trick is to apply thin coats rather than thick ones.

Bristol can be applied over cured*varnish in good condition.* It cannot be applied over wood that's had an oil finish applied in the past unless all traces of the oil are removed.* On raw wood the first coat takes awhile to cure, but subsequent coats dry quite fast, so multiple coats can be put on each day.* Bristol should also be applied over dry wood.* Any moisture in the wood can cause little bubbles to rise to the surface.* The good news is they can be sanded flat and the bubbles completely disappear with the next application.

Also, applying Bristol too late in the day so that dew or moisture forms on it before it has cured sufficiently will result in a milky finish.* But this disappears completely with the next application of Bristol.

Bristol is not a magic bullet, however.* To achieve a*lasting finish on wood that sits in the weather at least six coats are needed and more is better.* We try for ten although that's not always possible in the weather we have up here.* However, once that good base is established, under normal conditions a refresher coat should not be needed for at least two years.

Also, Bristol is no more resistant to moisture getting under and lifting it than varnish is.* The only proper cure for this is to remove the trim, remove the old finish, and properly*rebed the trim so the surfaces in contact with the boat and to adjacent pieces of trim are properly sealed.* I also seal the stripped wood with CPES before re-bedding and*starting to apply Bristol.

The mixing ratio of the two components is 8 parts of urethane base to 1 part of catalyst.* The can of base has a very long shelf life even after being opened.* Not so the little jar of catalyst.* Not a problem if you're doing a lot of finish work over a period of a couple of months.* I've found that I can extend the shelf life of an opened, partially empty jar of catalyst by sealing the cap with electrical tape and then storing the jar upside down.* Fortunately, the jars of catalyst can be purchased separately, so having a jar harden does not mean the partial can of base you have left cannot be used.

Brtistol is not cheap.* The basic quart package is about sixty bucks.* Varnish is significantly*cheaper to buy, but given its much shorter lifespan and the need to spend more time dealing with the brightwork, when we figure in the value of our time the Bristol is a bargain.



-- Edited by Marin on Wednesday 25th of November 2009 08:26:05 PM

Dear Marin,

I feel bad. You were making this very nice post about Bristol and I was next door picking on you. I hope it makes you feel better that I feel bad. If not I guess I owe you one. And I can say that if lots of my friends had trouble w Suzuki's I probably wouldn't buy them either but first I'd take stock of how handy my friends were.
Looks like Bristol is'nt for me in Thorne Bay. Especially now that I've put teak oil on. However as I recall you can recoat w Bristol every hour so 10 coats could almost be achieved in a day. Or am I thinking of some other product? Thanks for the nice post Marin and I'll try to be less critical in the future. Before I fall all over myself perhaps I should go back and see how you responded to my comments.

Eric Henning

Eric---

Ten coats a day is not possible with Bristol if the boat is outside. Given the requirement that the wood be dry which means you can't start as soon as it gets light, plus the initial cure time of each coat, plus the time it takes to apply the stuff to a boat length of handrails, caprails, etc., plus the need to leave a couple of hours beween the application of the last coat and the cooling and moisture increase in the air at the end of the day, the best I've been able to do in a single day is three coats. You could certainly do more if the thing you were finishing was small or if your boat was not outside. There needs to be about an hour between coats. Apply the next coat too soon and the brush starts putting streaks in the previous coat.

So we tend to treat Bristol like varnish. Put on one or two coats, then let it sit for the next five days when I'm working, then fine-sand, re-mask, and put on a few more coats the next weekend assuming the weather cooperates. This actually builds up a smoother surface than trying to put on as many coats at a time as possible.

And you're right--- if you've put teak oil on your wood Bristol won't work. You'd have to remove or weather out the oil completely. There used to be a finish remover that would actually penetrate wood and lift out old finish including oil--- I used to use it when refinishing walnut gunstocks in the 1970s--- but this stuff was so powerful and "dangerous" that it was taken off the retail market at least twenty years ago. It may still be available on a commercial basis, but you can't buy it in stores. The finish removers available in stores today, even the so-called powerful ones, are pathetic compared to what used to be available.

For real information get Practical Sailor.

They side by side test many products.

$50 a year and worth it.

FF

Those beautifully varnished strip built canoes and kayaks are generally finished with a layer of glass cloth in West system epoxy resin, followed by several coats of spar varnish. The spar varnish is required for its UV protection, othersies a coloured gel coat would be necessary to protect the epoxy.
Any brand of varnish will do, provided it has adequate UV inhibitors.
For ease of use, some prefer the cheaper brands, which in my experience are generally thinner and take more coats.
Some prefer the more expensive brands, to get a faster buildup.
My preference is Epifanes, as I have found it to level out and leave fewer flaws, with a faster buildup. Over the years I have tried most of the varnishes and some two part, and I keep going back to Epifarnes on my trawler.

We have more teak trim than 99% of the boats and I use Interlux Goldspar clear which is a one part Polyurethan that is a thick as varnish, goes on smooth, flattens well and dries in*a couple of hours.* I have applies multi coats, but prefer to lightly sand between coats for better adhesion but mostly to be able to see the areas that are missed.* After 10 months of 9 months of PNW rain, I apply 1 or*2 coats to referesh.* The areas the varnish has failed is due to the calking failing or the varnish ha been damaged.



For the really weather areas, I also have used West system Epoxy to build a thick layer then*several coats of*Interlux.* Lastly in Sept every years a apply Turtle Wax 21 protection to the entire exterior of the boat, pain, varnish, SS, port hole which makes the rain water bead off and the boat easier to wash.* Those black streaks usually wash off.* Easy spray on application and has UVA/UVB protection.* Give it a try you might like it.* Sure beat hand waxing.


-- Edited by Phil Fill on Thursday 26th of November 2009 01:17:01 PM

Phil re your post,I was looking for Turtle Wax 21 protectant and I found turtle wax F-21 listed as a tire cleaner/protectant listed for rubber and plastic is this the same one you have used?
Thanks,
Steve W.