Marine varnishes have been applied to protect and maintain teak on boats for many, many years. History indicates that varnishes used in the 1700s are very analogous to what is used today. The coatings allow for the rich beauty of the wood to be viewed while providing shelter 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 boat's exterior brightwork, how do you select among the astounding assortment of products? Knowing completely that this is as big a deal as arguing the differences of motor yachts vs. sailboats, we nevertheless provide the accompanying observations.

Just What is a Varnish

A varnish is a liquid finish ordinarily used to treat teak. Its principal ingredients are oils. resins, solvents, dryers and ultra-violet additives. The components are mixed in different proportions to give the best appearance and protection.

Oils

Wood Oils typically keep the new look and grain of the wood more than the other products because they permeate deeply into the wood fibers and do not produce as much of a surface coating. Wood oils are accessible in colors ranging from water clear to gold to dark brown. As with any wood finish, multiple coats generally result in a more consistent finish and greater longevity. We find oil to be the simplest to apply, since surface blemishes are not as obvious in the ultimate outcome. This does not mean, notwithstanding, that applying four coats of oil on raw teak will produce a Bristol finish. You'll also find that oil's thin consistency makes masking to protect surrounding gel coat and painted areas almost as crucial with oil as with varnish. Clean, sandpapered teak with a few coats of oil can give your teak 3-6 months of protection and beauty.

Tung oil is used frequently for teak applications.

Spar Varnish

Spar or marine varnish is a refined product consisting of oil, solvents and thinners, resins, dryers and additives. By varying the proportions of the components and by blending UV inhibitors and different secret ingredients, manufacturers make varnishes with widely varying characteristics. Varnishes can have a gloss or matte visual aspect, can be formulated to be super hard for walked-on surfaces and can deviate in color.

The 2 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 provide the classic golden look. Oil modified polyurethanes tend to be more clear, permitting the color of the teak to shine through.

Newer varnishes, provide improved durability in the harshest of environments such as the hot, Florida sunlight. Teak moves, and since it is a formerly living thing, it enlarges and compresses with even small changes in temperature and humidity. The best varnishes contend with this unstable material using high quality Oils and resins and a greater percentage of solid components, offering a longer lasting, more flexible coating with a greater gloss.

Mil thickness is everything. Six to ten coats is usually necessary to get a quality look. A good base coat, annually maintained with maintenance coats, will give the ultimate in appearance, longevity and protection. Despite the initial effort (up to ten coats are common) nothing appears better than exterior brightwork finished with gloss varnish.

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

Synthetic Teak Finishes

These coatings gained popularity with cruisers in Florida and the Bahamas searching for UV-resistant low-maintenance exterior teak. Formulated for simplicity and speed, these products have remarkable durability for outside use, are simple to apply and look comparatively good. I say comparatively good as some of these finishes, like Silkins Cetol, have a colored appearance, sometimes with an orange tone. You must be cautious not to apply too much. Some varnishes such as Interlux Goldspar and Schooner are made with no pigment so the wood's beauty is saved. 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 apply it immediately over sanded, clean wood. I know of one professional that applies Cetol entirely and his work is fantastic.

Cetol comes in four varieties, with the new Natural providing a more golden color resembling the real appearance of raw teak. You can overcoat any of the other pigmented Cetol finishes with the Gloss for a shiny exterior finish.

Two Part Teak Urethane Finishes

Another finish to make an appearance in the cruising world are the urethane two-part products. Fashioned to replace traditional varnishes, these products have made a mark in the boating community. Their manufacturers produced these finishes to hold up in tropical environments for years at the time. One maker, C Tech Marine, sports that its product Bristol Finish is used on numerous cruise ships, certifying to its beauty and longevity.