Teak Treatments: Round Three
Smith & Company and Honey Teak outshine the rest; Cetol Marine pins Armada in the matte class.
While a head-to-head comparison of teak treatments for longevity may not produce the breathless excitement of, say, a winter Olympics luge or curling competition, it undoubtedly is of more immediate concern to the boater owner. Teak has long been the choice of materials for marine decking and exterior trim, although more and more boatbuilders are doing away with exterior teak in the interests of easier maintenance.
As we’ve often said before, teak certainly has its good points: It’s dimensionally stable, it has great nonskid characteristics for decks, and it does a fine job of resisting rot. When it’s new, or freshly sanded, it has a beautiful yellow-to-brown color, and a pleasant grain. If you do your boating in an area with very low air pollution, this color fades to a silvery gray-white, which also looks good—something like the color of cedar siding.
Trouble is, very few of us are fortunate to have air that’s that clean. Acid rain, dust, and smoke will turn our teak into an ugly gray/black in less time than we care to think about. Short of almost-continual scrubbing and bleaching (which destroys both teak and tempers) or painting (which defeats the purpose of having teak in the first place), most boaters have resigned themselves to applying an oil or varnish to stand between the teak and the weather. And then reapplying it in the course of a few months.
Eight years ago, we pretty much gave up on teak treatments, equating all the ones we tested with snake oil insofar as their performance failed to match up to their glowing claims. “Deep-penetrating”...“Lasting Beauty”...“Prevents Weathering”—all of these looked better on the labels than on the teak. More recently, though, we’ve encountered some products that do work. We applied a bunch of them to teak panels back in August of 1995, put them up on the roof of a Connecticut office building, and left them out in the weather. After two-and-a-half years, we’ve found three products that are still going strong.
How They Work—And Fail
Bare teak is attacked primarily by water and sunlight. Water causes the wood to swell and check, while the ultraviolet (UV) portion of sunlight can cause decomposition of the wood. Wood consists essentially of fibers of cellulose bonded together by a material called lignin, which breaks down under exposure to UV.
Applying a coating to interpose between the wood and the weather helps preserve the wood. Teak treatments can consist of non-drying oils (which don’t form a solid film, and wash off easily), or of more-permanent film-formers like varnishes (which use liquids that combine with atmospheric oxygen to create a solid film), or of two-part resin systems (in which the two components react with each other upon mixing to polymerize to a solid film).
Unfortunately, that’s only a partial answer: UV can penetrate clear coatings and continue to do damage to the wood beneath. And UV can—and does—destroy the coatings. You can minimize this by incorporating particles of finely divided opaque materials into the coating; these block the transmission of UV and limit degradation to just the outer surface of the film. This also turns the film into paint, which isn’t an effect most boaters wish for.
Which brings us to UV absorbers. These are chemical compounds that absorb UV, keeping it from damaging the coating or the wood underneath while maintaining the coating’s transparency. UV absorbers act in somewhat the same manner as the sacrificial zincs that protect your motor and drive system; each time some UV is absorbed, some of the absorber is depleted. Eventually, the UV absorbers are exhausted and are incapable of protecting the coating and/or the wood underneath.
Why not just put in more absorber? The main reason is cost. UV absorbers in a coating often cost considerably more than all the other ingredients in the coating put together (another reason, of course, is that you need enough of the other ingredients to create a substantial continuous film).
Just to make things a bit more complicated, stray UV that isn’t intercepted by UV absorbers can break the long chains of molecules that form the solid film. When this happens, the broken chain ends can attach themselves to neighboring chains, eventually replacing the long chains (which make for flexibility) with densely cross-linked short chains (which make for brittleness). The usual remedy for this, from a paint formulator’s viewpoint, is to add chemicals that will react with the broken chain ends and prevent undesired cross-linking. These chemicals—called antioxidants—work in exactly the same way as do antioxidant vitamins in your body, except that what they keep healthy is your teak finish.
These antioxidants can’t be used in conventional varnishes, which depend upon oxidation to cure. As a result single-component varnishes continue to grow more brittle with time. Two-component coatings don’t have this problem.
Another problem is that of the coating’s adhesion to the underlying wood. If adhesion isn’t excellent, it’s easy for moisture entering from chips or scratches in the finish to find its way under the coating and cause an otherwise intact film to separate from the teak. This has led some manufacturers to sell clear basecoats for adhesion and clear topcoats for UV resistance.
As we pointed out last year, there seem to be two schools of thought when it comes to teak maintenance: One group simply wants the finish to last as long as possible without the need for attention, while another group is willing to provide frequent periodic maintenance—typically every few months—as long as that maintenance is easy. We tend to side with the first group, but we’re considering maintenance problems in making our recommendations.
For the past 30 months, we’ve been exposing treated teak panels to the Connecticut weather all year round. We found that 12 of these treatments—Z-Spar’s Captain’s Waterbased Varnish, Star Brite Teak Oil, and Semco’s Teak Sealers—Gold Tone, Gold Tone/Natural, Classic Brown, and Natural, as well as Semco’s Waterbased Low VOC Teak Sealer, both used alone and as a topcoat for each of the Semco Teak Sealers—failed within six months, We returned the remaining seven products to the roof, along with panels re-coated with the products that had failed, and pulled them down for inspection a year later.
The 12 panels that we had re-coated all failed. All but one of the previously successful products continued to hold up well—Armada Gloss represented our sole failure in this group (the company says it has since increased gloss by 10%). We took the seven survivors and subjected them to some violent abuse involving knives, punches and ball-peen hammers. We wanted to see if they’d crack or chip, and we wanted to provide some potential failure sites for water entry. We then returned them to their south-facing outdoor racks. Twelve more months passed.
Here's what we found.
Armada Teak is a semi-gloss, semi-transparent film-forming stain that’s a one-component system. It takes three coats, with a 24-hour dry time specified between coats, requiring 48 hours total for a complete application. Once applied, the product darkens the teak somewhat, leaving an orange-brown surface with a somewhat “painty” look—the teak’s grain is visible, but isn’t as sharp or well-defined as would be the case with a completely transparent treatment.
After 30 months, the surface was visibly dulled, but seemed intact (it passed our water beading test, and there was no visible damage to the teak). Scratched surfaces showed discoloration at the scratches with no spreading beyond the original scratch. Sanding and touching up restored the original appearance.
Bottom Line: A good choice if you opt for a low-maintenance semi-gloss finish—if you don’t mind the orange/brown color. It doesn’t hold up quite as well as the Cetol Marine in extended use.
Cetol Marine is a product that’s quite similar to Armada Teak. Actually, it came first in the form of a deck coating and a prototype marine product (with extra UV inhibitors). It was the first viable teak oil we'd encountered and has since acquired something of a cult status. Cetol is a bit less transparent than Armada Teak, and provides a slightly “paintier” look, but the differences in initial appearance are extremely minor.
After 30 months, our Cetol-treated samples looked and acted virtually unscathed, maintaining both their ability to bead water and their original semi-gloss look. Scratched surfaces behaved much as they did with Armada Teak. It’s going back up for another year without re-coating.
Bottom Line: The only semi-gloss product we tested that showed no appreciable change in two-and-a-half year’s worth of exposure. Our choice if you don’t want a gloss finish, but we wish it came in some other color.
Awlbrite Plus is a two-component clear coating: You mix two parts of base to one of converter (adding reducer to thin, if desired). The instructions are clear, complete, and somewhat intimidating. The first coat requires a drying time of at least eight hours, after which you sand lightly. Subsequent coats require a dry time of at least three hours between coats, with no more than two coats in a 24- hour period. The pot life of the mixed Awlbrite is 60-90 minutes, so you have to mix a fresh batch for each coat. The 10 coats we applied required six days.
If you allow more than 36 hours to elapse between coats, you must sand or scuff the surface—a nuisance for weekend warriors. We had a bit of trouble with bubbles, although the finish dries quickly enough to minimize bug entrapment.
Awlbrite Plus gave us a brilliant high-gloss surface, leaving the wood with a dark brown color. Grain showed up beautifully. We noted a slight haze in the finish after 18 months, which became much more pronounced after 30 months.
The finish is very hard, so that minor scratches aren’t too likely; a scratch that penetrated the film, though, admitted water that seeped under the film. Adhesion was destroyed to the extent that we could lift the film of coating from the underlying wood with little effort.
Bottom Line: Awlbrite’s brilliant gloss and attractive appearance are offset by relatively poor adhesion. Others do better.
Cetol Marine w/ Cetol Gloss
Cetol has chosen to go the two-step route, calling for an application of three coats of their Cetol Marine (24 hours between coats) followed by three coats of Cetol Marine Gloss (same drying times). The result looks like a somewhat shinier version of the Cetol Marine semi-gloss. The combination held up well for 18 months, but exhibited severe dulling, cracking and flaking during the last 12 months of exposure.
Bottom Line: Cetol’s gloss version doesn’t hold up as well as their well-established semi-gloss product.
Honey Teak is a two-step—basecoat plus topcoat—system in which each step involves two components plus a reducer. This makes for a somewhat intimidating six cans of product. Happily, the manufacturer’s formerly disorganized and confusing instructions have been completely rewritten and are much simpler to follow (dare we say “user-friendly”?)
The product is easy to use. The basecoat has a pot life of six to eight hours, and you only require 20 minutes or so between coats. The topcoat has a similar pot life and only requires 40 minutes between coats. As a result, you only have to mix one batch of each, and (as the manufacturer points out) you can apply all three basecoats and five topcoats in one day. We were lazy, and took two days for the job. About the only caution the manufacturer offers is to make sure that the basecoat doesn’t harden beyond the tacky stage between applications. If you put off the next coat until the next day, you will have to scuff the surface with a scrubbing pad to insure good adhesion.
We found Honey Teak easy to apply, with its rapid drying time helping to minimize dust and bug entrapment. We wound up with a high-gloss, moderate orange-brown surface that shows little or no signs of wear after 30 months of exposure.
Honey Teak seems to provide a more flexible film than do the other gloss products we tested. Scratches—even deep ones that penetrated the film—had no visible effect upon adhesion and showed no signs of water diffusion beneath the coating. Touching up was simple, as was blending in the touched-up portion with the original topcoat.
Bottom Line: After a rough 30 months, Honey Teak has shrugged off everything that Mother Nature threw at it. We’re not overly fond of the orange/brown color, but we’re growing fonder of it as the tests progress. A winner.
CEPS w/ 5 Year Clear Topcoat
Smith & Company markets a system that, from a user’s viewpoint, is much like Honey Teak. It’s a bit difficult to write about, as the system has no singular name, and the topcoat has had its name changed from a modest “Polyurethane Topcoat” to a more ambitious “Five Year Clear.” Whatever you call it, the system consists of two steps, with each step requiring two components plus reducer. Smith also supplies two different clean-up solvents, one for each step for a grand total of eight cans. One tester commented that it looked like a chemistry set. Instructions were detailed, complete, and clear, and once over the shock of dealing with all those cans, our testers found the system quite easy to use.
The first step is what Smith calls Clear Epoxy Penetrating Sealer, or CEPS. Instructions call for two coats of CEPS, applied 24 hours apart. Any sanding required should be to the first coat. After another 12 hours, you start applying the polyurethane topcoat, allowing four to six hours between coats, with no more than two coats per day. We used the upper limit of the recommended two to five coats of topcoat.
The entire job, as we did it, takes four days. There’s a fair amount of measuring and mixing required—the CEPS must be mixed twice (one for each coat) and the topcoat has a pot life of two to three hours.
The result is a walnut-tone deep-gloss finish that’s reminiscent of those 40 -coats-of-hand-rubbed-varnish finishes you used to see on classic yachts. We encountered no bubbling or running during application.
After 30 months, we could observe no change whatsoever in color or gloss. Maybe that Five Year business isn’t just hyperbole. The finish is quite chip- and scratch-resistant, although we did see some very faint signs of moisture spreading at the base of one particularly deep scratch. Retouching isn’t as easy as it was with Honey Teak, because CEPS’s hard finish makes it difficult to blend in the retouched area with the original, but the surface is sufficiently scratch-resistant so that this may be a moot point.
Bottom Line: It’s not for decks or stairs, but, at least for 30 months, Smith and Company’s Clear Epoxy Penetrating System produced the most impressive gloss finish we’ve seen yet. Another winner!
We recognize that our test protocol is a severe one—teak treatment manufacturers typically suggest additional yearly recoating, and we’re quite sure that, had we followed such a regimen, we’d have more products that survived. We feel, however, that life is short, and one’s time is better spent sailing than treating teak. If a product survives in decent shape without maintenance, we prefer it to a product that requires maintenance.
Our survivors are going back into the weather as of this writing, along with some other products we’ve encountered more recently.
Our recommendations are simple: If you want a matte finish, Cetol Marine is our top choice, although Armada Teak’s performance can’t be considered at all shabby.
For a gloss, we think you’d be happiest with Smith and Company’s system (CPES plus Five Year Clear) or Honey Teak. We know you'll be happy with the lack of maintenance.
Both of these high-gloss products are demonstrating exposure resistance the likes of which we’ve never encountered. Smith and Company’s system, we feel, is the winner for looks (viewers’ responses seem to range from ooh to wow); Honey Teak is easier to apply and probably easier to maintain as well.
See y’all next year.
Contacts- Armada, Armada Coatings, P.O. Box 879, Havre de Grace, MD 21078; 800/336-9320. Cetol Marine, Azko Coatings, 1845 Maxwell St.,Troy, MI 48084; 800/833-7288. Awlbrite, U.S. Paint, 831 South 21 St. St. Louis, MO 63103; 314/621-0525. Honey Teak, Signature Finish, P.O. Box 1041, Port Salerno, FL; 561/287-6077. Semco, Box 323, Phoenix, MD 21131; 800/662-0223. Smith and Co., 5100 Channel Ave., Richmond, Ca 94804; 510/237-6842. Starbrite, 4041 SW 47 Ave., Ft. Lauderdale, FL 33314; 305/587-6280. Z-Spar, Woolsey/Z-Spar Marine Paint, 36 Pine St., Rockaway, NJ 07866; 800/221-4466.