The Best Marine Varnish: Exterior Wood Finish Tests

Two-part varnishes leading in durability as long-term test reaches 24-month mark.


[Updated December 5, 2018]

Like spotting land after a long passage, were glad to say that the end of our longterm exterior wood finishes test is finally on the horizon. Time, weather, and Southwest Floridas unrelenting sunshine have clearly taken their toll on the test panels over the last 24 months, and as the evaluation moves into its third year, only 19 of the original 54 test products will continue on in our survival-of-the fittest finish matchup. Given that most wood coatings are rarely expected to last longer than two years in the marine environment-particularly in super-sunny locales-its no surprise that weve seen more significant changes in the coatings in the last six months than we had in previous checkups.

marine Varnish

Bottom photos by Frank Lanier

Our search for the ideal wood finish-relatively easy to apply, easy to maintain, lasts multiple seasons, and is affordable-began in 2007 when we took a look at the different types of exterior wood finishes on the market, their pros and cons, and how easy they were to apply (one-part varnishes, August 2007; varnish alternatives, October 2007; two-part varnishes, December 2007; teak oils and stains, April 2008). Launched in 2008, the longterm panel test aimed to determine which type of coating offers the best and longest protection and which products stand out among their peers.

We hope the comparison enables readers to decide which finish best matches their own taste, potential labor investment, and wood protection needs.

Weve rated the test products every six months and reported on the coatings durability in the May 2009 issue (six-month checkup), December 2009 issue (12 months), and January 2011 (18 months) issues. Here, we offer the two-year report on the survivors.

How Were Testing the Marine Varnishes

Testers applied dozens of exterior wood finishes (22 one-part varnishes, six two-part varnishes, 18 synthetics and satins/varnish alternatives, and eight teak oils and sealers) to small panels of bare solid teak. Each was assigned a number for blind judging and was applied per manufacturers instructions. If makers gave a range for the number of coats to apply, testers went with the minimum.

Initial testing rated each products ease of application and original gloss and reflective qualities. In the summer of 2008, the test panels were mounted on a wooden rack (aka: The Rack), which was set up in an unobstructed area on the roof of the PS workshop in Sarasota, Fla., to ensure that all panels received the same amount of weather exposure. The top part of each panel was covered to create a control area that testers used for comparison over time. Every six months, we disassembled The Rack and rated the panels on how well their coating integrity, gloss, and color had fared over time with constant exposure to the elements.

The test was designed as an endurance test, a fight to the finish, so we have not done any maintenance coats or touchups to the test panels. These products can be expected to have much longer lifespans if they are regularly maintained.

How Were Rating the Marine Varnishes

Testers rate each panel on three longterm performance criteria: coating integrity, gloss retention, and color retention. Excellent and Good coating integrity ratings mean that no maintenance is needed; a Fair indicates that its time for a maintenance coat; Poor means the fat lady has sung, and the coating would need to be removed and re-applied. Excellent ratings are given only to those with an uncompromised coating. This time, panels with Poor and Fair- coating integrity were pulled from the test.

Color and gloss retention ratings are relative to the panels original finish. Initial gloss and ease of application are relative to the field within each coating category; these were assigned immediately after the panels were coated.

It was tougher to pick Recommended coatings at the two-year mark, as most wood finishes arent intended to go that long without maintenance. One-part varnishes that earned PSs recommendation this go-round were rated Fair for coating integrity (none rated better than Fair ) and had no Poor ratings. Recommended two-part systems rated Good or better for coating integrity with no Poor ratings. No varnish alternatives or teak oils/sealers were recommended at two years.

VALUE GUIDE: Varnish Alternatives

Epifanes Rapidclear $26/ quart Poor Poor Fair Fair Good Fair Excellent Clear/satin
Interlux Sikkens Cetol Marine (alone) $25/ quart Fair N/A Fair+ Excellent N/A Good Excellent Opaque amber/ matte
Interlux Sikkens Cetol with Marine Gloss $25/ quart (Gloss $28) Fair+ Poor Good Excellent Excellent Good Good Opaque amber; clear overcoat/ Satin
Interlux Sikkens Cetol Marine Light (alone) $25/ quart Fair N/A Fair Good+ N/A Fair Excellent Opaque light amber/ matte
Interlux Sikkens Cetol Marine Light with Marine Gloss $25/ quart (Gloss: $28) Fair+ Poor Good Excellent Excellent Good Good Opaque amber; clear overcoat/ satin
Interlux Sikkens Cetol Natural Teak with Marine Gloss $26/ quart (Gloss: $28) Fair- Fair Poor Good Good Fair Good Golden-translucent, clear overcoat/ satin
Le Tonkinois Bio Impression with Vernis N/A Fair Poor Fair Good Fair Fair Good Warm, dark amber/ high gloss
West Marine WoodPro Plus Semi-Gloss $30/ quart Poor Poor Fair Fair Fair Fair Good Clear/ satin
WoodPlus Marine Natural $21/ quart Fair- Poor Poor Good Good Fair Excellent Reddish brown/ low gloss
Ace Spar Varnish Gloss 16373 $13/ quart Fair- Fair- Good Good Good Good Excellent Good
Coelan (with primer) $145/ kit Fair- Fair Fair- Excellent Excellent Good Good Excellent
Deft Defthane Poly Satin $13/ quart Fair- Poor Fair- Excellent Good Good Excellent Fair
Detco Crystal $41/ quart Good- Fair Fair- Good Good Good Fair Good
Epifanes Clear High Gloss $27/ quart Fair- Fair- Good Excellent Excellent Good Good Excellent
Epifanes Wood Finish Gloss $36/ quart Fair Poor Fair Excellent Excellent Good Good Excellent
HMG K Type Varnish $30/ liter Poor Poor Poor Excellent Good Fair Good Excellent
Interlux Goldspar Cllear N/A Fair+ Fair- Fair+ Good Excellent Good Good Excellent
Interlux Jet Speed N/A Fair Poor Fair Fair Fair Good Excellent Excellent
Interlux Schooner $23/ quart Fair+ Fair- Poor Good+ Good Fair Good Good
Le Tonkinois No. 1 $35/ liter Fair- Poor Fair Fair Fair Good Excellent Excellent
Le Tonkinois Vernis $33/ liter Fair+ Fair- Fair+ Excellent Fair Good Excellent Excellent
Minwax In/Outdoor Helmsman Spar Urethane $17/ quart Fair Fair Poor Good Good Fair Excellent Excellent
Pettit Bak V-Spar 2053 N/A Fair- Poor Poor Fair Poor Fair Excellent Excellent
Pettit Z-Spar 2015 Flagship $30/ quart Fair Fair Fair Good Excellent Good Excellent Excellent
Pettit Z-Spar Captain’s 1015 Traditional Amber $28/ quart Fair- Poor Fair Excellent Good+ Good Good Good
Pettit Z-Spar Captain’s EZ Care 1016 (Woolsey) N/A Fair Fair- Good Good Good Good Excellent Good
West Marine 5-Star Premium $32/ quart Fair- Poor Fair Excellent Good Fair Good Excellent
Bristol Finish, Traditional Amber $70/ kit (1 quart) Poor Fair Good Fair Excellent Good Excellent Excellent
HMG Acrythane XSC $45/ liter Fair Good Fair+ Good+ Excellent Good Good Good
Honey Teak with overcoat $2/ sq. ft. Fair- Good Fair Fair Good Good Excellent Excellent
Interlux Perfection $60/ kit (1 quart) Excellent Excellent Good Excellent Excellent Good Good Excellent
Nautiking NautiThane $120/ kit (1 quart) Good Good- Good Excellent Excellent Good Excellent Good
Smith Five-Year Clear N/A Good Good Fair Good+ Excellent Good Good Excellent

What We Found

What a difference a season makes! With the exception of a few two-part products, the test coatings had lost their sparkle at the two-year mark. Ratings slipped across the board. The UV abuse had obviously taken its toll, sucking the life out of most of the coatings, particularly the clear finishes.

Those clinging to life with Fair coating integrity are still protecting the wood, but theyve lost their looks. In the real world, all of the one-part varnish and varnish alternative test panels would be due for a maintenance coat, and some-like HMG K Type Varnish, West Marine WoodPro Plus (rebranded Epifanes Rapidclear), and Ace Spar Varnish-would be overdue.

The biggest overall decline was within the one-part varnish test group: Not a single one rated better than Fair for coating integrity or gloss retention, and nearly half of the test field was retired after this rating round. Just six months before, eight of the 19 products rated Good for coating integrity and six rated Good for gloss retention. In 12 months, seven dropped from an Excellent coating integrity to a Fair.

The one-part varnishes offering the most protection after two years are Detco Crystal, Le Tonkinois Vernis, and Pettits Z-Spar Captains 2067. However, their extended protection comes with tradeoffs: Detco rated only Fair for application, Le Tonks gloss started to slip after one year, and Pettits 2067 started losing its original color after 12 months.

One hardware store varnish has surprisingly held its own over the long haul: Minwax Helmsman Spar Urethane. At half the cost of the Recommended one-part varnishes, Minwax slacked in the color retention department, but it has proven its multi-season durability.

Four of the nine varnish alternatives have been voted off The Rack after two years, and none performed well enough to earn our recommendation for two-year wood protection.

Interlux Perfection marine varnish

The Cetol products are still at the head of the pack, albeit a somewhat mangy-looking pack. The cloudy, opaque look of the Cetol Marine and Marine Light products may not appeal to everyone, but the fact theyve maintained their color for more than a year is a good example that higher-solids finishes tend to offer better UV protection.

The Cetol Natural (with gloss) test panel fell from a Good coating integrity six months ago to being dropped from testing. Its performance mirrors what weve seen in the field: Give it a little loving once a year with a scrubby pad and a fresh coat, and itll last the long haul.

Its taken two years, but the two-part varnishes are finally starting to show their age. Surprisingly, the first products to be dropped from this group are two that performed well in past PS tests: Bristol Finish and Honey Teak. This is likely because the life of a wood finish in Florida is always going to be shorter than in our past test locales in New England.

The other two-parts are still holding up well, with Interlux Perfection and Nautiking Nautithane offering uncompromised protection and better-than-expected gloss after 24 months. Perfection has been reformulated since the test began and is now sold as Perfection Plus.

The temporarily discontinued (since 2009) Smiths Five Year Clear has also proven to be a top-notch finish, but its not available at this time.

While HMG Acrythane XSC didnt earn our Recommendation this time, it was a top 18-month finish, it still looks good, and it costs less than the Nautithane.

Conclusions About Exterior Varnishes

After two years of testing, weve come to accept that perhaps theres no Holy Grail of exterior wood finishes. It would appear, unfortunately, that we cant have it all: easy to apply, easy to maintain, long-lasting protection, and a budget-friendly price tag. The reality is that, like much in life, wood protection is all about compromise and balancing your needs with your wants.

Theres no one-size-fits-all solution, and the boat owner who finds gratification in the wet, glossy look of a two-part varnish borne of painstaking preparation and careful application will weigh our test data much differently than the one who regards brightwork maintenance as a masochistic endeavor. For the latter, we recommend seeking out a varnish alternative (easy to apply, easy to maintain) that suits your tastes. With modest maintenance, the Cetol products with gloss overcoats have proven to be the most durable.

For areas where slippery-when-wet coatings wont do, Cetol Natural (without gloss overcoat) or our top-pick teak oil, Star brites Tropical Teak Sealer (classic teak) should be considered. The Star brite will need to be reapplied every three or four months.

If youre looking for a harder, more abrasion-resistant finish thatll make it past the year mark, check out the top one-part varnishes like Detco Crystal or Pettits Z-Spar Captains 2067. Boat owners in sailing areas that see less sunshine than our Florida test site should also consider Pettits Flagship 2015 or Captains 1015. One-part varnishes require a little more work upfront and quick attention when they are scratched or dinged, but they also offer a more traditional, high-gloss look. The one-part varnishes in our test slipped dramatically after a year and half, so we suggest an annual maintenance coat, whether they look like they need it or not.

As this test has shown, when it comes to long-lasting protection and gloss, two-part varnishes just cant be beat. They may be a pain to apply-and should you let the coating fail, you had better invest in a heat gun-but their durability is unmatched.

The top two-part after two years of testing was Interlux Perfection. Because weve not yet tested the reformulated Perfection, the top pick honors go to Nautikings Nautithane. While its price tag ($120 per quart kit) is a bit hard for most of us to swallow, Nautithane earned across-the-board Good ratings after two years.

Test Boat Report
Darrell Nicholson, editor of Practical Sailor, grew up boating on Miami’s Biscayne Bay on everything from prams to Morgan ketches. Two years out of Emory University, after a brief stint as a sportswriter, he set out from Miami aboard a 60-year-old wooden William Atkin ketch named Tosca. For 10 years, he and his girlfriend Theresa Gibbons explored the Caribbean, crossed the Pacific, and cruised Southeast Asia aboard Tosca, working along the way as journalists and documenting their adventures for various travel and sailing publications, including Cruising World, Sail, Sailing, Cruising Helmsman, and Sailing World. Upon his return to land life, Darrell became the associate editor, then senior editor at Cruising World magazine, where he worked for five years. Before taking on the editor’s position at Practical Sailor, Darrell was the editor of Offshore magazine, a boating-lifestyle magazine serving the New England area. Darrell has won multiple awards from Boating Writer’s International, including the Monk Farnham award for editorial excellence. He holds a U.S. Coast Guard 100-ton Master license and has worked as a harbor pilot and skippered a variety of commercial charter boats.



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