Choosing a Varnish for Your Boat's Brightwork

Marine varnishes have been used to protect and maintain exterior teak on yachts for hundreds of years. History bears witness that varnishes used in the 1700s are very akin to those used nowadays. The coatings provide for the rich beauty of the teak to be seen while offering protection from rain and sun. The finish achieved after careful application will vary from a soft patina to a high gloss finish found on fine furniture.

Assuming you want to protect and embellish your used trawler or sailboat exterior brightwork, how do you select among the incredible assortment of finishes? Recognizing full well that this is as big a deal as debating the differences of power vs. sail, we nevertheless provide the accompanying observations.

What is a Varnish

A varnish is a liquid coating ordinarily applied to treat wood. Its primary components are oils. resins, solvents, dryers and ultra-violet additives. The components are mixed in various proportions to give the best appearance and protection.

Oils

Wood oils typically maintain the new look and texture of the teak more than the other finishes because they permeate deeply into the wood fibers and do not create as much of a surface coating. Oils are accessible in colors ranking from water clear to gold to dark brown. As with all wood finish, many coats generally result in a much more consistent finish and greater longevity. We learn oil to be the easiest to utilize, since surface blemishes are not as obvious in the final outcome. This doesn't mean, notwithstanding, that applying several coats of oil on dirty teak will produce a great finish. You will also find that oil’s thin consistency makes masking areas to protect adjacent gel coat and painted surfaces almost as important with oil as with varnish. Clean, sandpapered teak with a few coats of oil will provide 3-6 months of beauty and protection.

Tung oil is used frequently for teak applications.

Spar Varnish

Spar or marine varnish is a refined finish consisting of oil, solvents and thinners, resins, dryers and other additives. By changing the proportions of the elements, producers create varnishes with widely varied characteristics. Varnishes can have a gloss or matte appearance, can be formulated to be extremely hard for high -use surfaces and can deviate in color.

The two most routine types of varnishes are traditional varnishes made with tung oil and newer polyurethane coatings. Natural tung oil varnishes are excellent for marine use and offer the traditional golden look. Oil modified polyurethanes tend to be more clear, permitting the color of the teak to shine through.

Recent varnishes, furnish better durability in the worst of environments such as the hot, tropical sunlight. Teak moves, and since it is a previously living plant, it expands and contracts with even subtle changes in temperature and humidity. The best varnishes contend with this unstable wood using high quality oils and resins and a higher percentage of solid ingredients, providing a longer lasting, more elastic finish with a higher gloss.

Mil thickness is everything. Six to ten coats is normally necessary to get a quality look. A sound base coat, annually cared-for with maintenance coats, will give the ultimate in appearance, longevity and protection. Despite the original effort nothing appears better than exterior teak finished with gloss varnish.

Interlux’s Original 90 is one of many brands of traditional spar varnishes on the market.

Synthetic Teak Finishes

These applications gained popularity with cruisers in Florida and the Bahamas looking for UV-resistant low-maintenance brightwork. These finishes have uncommon durability for outside use, are easy to apply and look comparatively good. Some spar varnishes such as Interlux Goldspar and Schooner are produced with no pigment so the wood’s beauty is protected. Full gloss and depth vs. convenience is the trade-off with these finishes, but simplicity and time savings can more than compensate. Applying synthetic finishes is akin to teak oil, where you can lay it immediately over sanded, clean wood.

Cetol comes in four forms, with the new Natural providing a more golden color like the real look of raw teak. You can overcoat any of the other pigmented Cetol finishes with the Gloss for a shiny exterior finish. I know of one professional that applies Cetol exclusively and his work is fantastic.

Two Part Teak Urethane Finishes

Another finish to show up 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 manufacturers produced these finishes to hold up in tropical conditions for years at the time. One maker, C Tech Marine, boasts that its product Bristol Finish is used on many cruise ships, certifying to its beauty and longevity.