RESTORING GELCOAT WITH ACRYLICS
The like-new shine from a liquid acrylic coating is hard to beat but it must be maintained annually.
When compounding, waxing or polishing fails to restore the color and gloss in gelcoat, you have two refinishing choices: overcoating with an acrylic finish or paint. Acrylic finishes are economical and easy to apply, but require annual recoating. Paints give long-lasting results and are virtually maintenance-free, but are expensive. For badly chalked boats, where fiberglass matting shows through the surface, or gelcoat with deep cracks, gouges or severe crazing repaired with epoxy, painting is your only option.
If the gelcoat surface is in good condition, an acrylic finish restores shine and color to oxidized and faded hulls, decks, cabin tops, even non-skid, without buffing, waxes or polishes. Acrylic coatings are one-part clear liquids based on acrylic polymer formulations that resemble self-polishing floor waxes. A minimum of four ultra-thin coats are applied in quick succession with a soft cloth or brush. The first few coats fill the pores in the gelcoat. Successive coats form a protective plastic coating with UV inhibitors that seals the gelcoat and dries to a clear, glossy finish.
Last fall, we tested three brands of acrylic finishes: New Glass, Vertglas and TSRW. (Star brite and Higley are two brands widely available not included in our test.) All three are packaged with enough solution to restore a 7.2m to 12m (24' to 40') boat. Our test boat was a badly oxidized, originally canary-yellow Laser II hull, kindly supplied by Bronte Harbour Yacht Club in Oakville, Ont. We taped and masked off five sections from the keel to the gunwale, leaving untreated control areas in between. Two non-acrylic finishes -- Meguiar's #44 overcoated with #55, and Iosso Fiberglass Reconditioner -- were applied to two of the control panels.
SURFACE PREP
The key to a successful job is correct application -- read the directions for best results. TSRW actually puts a warning statement on the instruction sheet: "If you do not read these directions, please do not use this product." Enough said.
Surface preparation calls for a thorough cleaning to remove wax, oxidation, grime, exhaust stains, oil, mildew and other contaminants. Cleaning is critical: any contaminants left on the surface will be sealed in after coating. TSRW's kit includes a bottle of Quick Strip, an undiluted solution of household ammonia, a bottle of 12 Plus, a chamois applicator and a Duramitt, a rubber mitt with an integral scouring pad (you'll want to keep this for future maintenance jobs). Manufactured by Edgewater Products in Portland, Oregon and widely distributed in North America, the kit sells for CDN$79.95/US$58. We cleaned our test patch with a solution of one-part Quick Strip diluted with three-parts water, let it sit for three minutes, wetting the hull as needed to prevent it from drying, then scrubbed the surface with the Duramitt and rinsed well. (A Roto Brush does this job faster and easier, if you have one.)
New Glass is made by Florida Marine Chemical in St. Augustine, Fla., and handled in Canada by Skipper's Choice Marine Products, Whitby, Ont., New Glass doesn't include a cleaner with the kit (CDN$44.95/US$39.95), so we treated the test section with a diluted Super Tuff solution, although you can use any heavy duty boat cleaner. If the gelcoat still looks chalky after drying, cleaning has not removed all the oxidation. For very faded boats, both New Glass and TSRW recommend a wet sanding with 800-grit or finer paper before cleaning.
Based in Elmhurst, Ill., Vertglas offers a three-step system that includes an Oxidation Remover, Boat Wash and Color Restorer/Sealer. Products are sold individually or packaged in a kit (US$49.95) with a large foam-type brush and a Sealer Remover (if you need to remove the finish). (In Canada, the kit sells for the same price but does not include the Boat Wash or Remover, which are sold separately.) Following the directions carefully, we applied the Oxidation Remover then scrubbed the test area until yellow appeared on the scrubber. You may skip this step if there is no apparent oxidation on the surface. Our sample kit provided by the Canadian distributor (Alex Milne & Associates, Brampton, Ont.) didn't include the Boat Wash so we cleaned the test area with Boat Armor Universal Marine Cleaner.
Wear gloves, goggles and protective clothing when working with any of these products. After cleaning, rinse well and let the surface dry.
APPLICATION
We selected a warm, low humidity, windless day with no rain in the forecast for at least 24 hours. Acrylics work best when applied in temperatures between 10C and 35C (50F to 95F). They can be applied in direct sunlight, provided the surface is not hot to the touch.
Acrylics are not difficult to apply, but their fast drying times leave little room for error. Beginning with New Glass, we poured a small amount into a container and applied it in long, straight strokes, overlapping slightly, using the supplied applicator and spread the coating as thin as practical; thick coats will not cure properly and give a streaky, hazy finish. If the liquid begins to foam (like soap suds), reduce pressure on the applicator. Acrylics dry extremely fast, so you need to always work to a wet edge or a completely dry edge. With two minutes or less drying time between coats, depending on the temperature, four coats goes on fast -- you can easily refinish a 9m (30') boat in less than two hours.
Both New Glass and TSRW supply a small chamois-like sponge to apply the acrylic coating. The Vertglas applicator, a plastic, foam-type brush with a chamois glued to the foam, gave better control and a more even coat. New Glass dried the fastest, in about 30 seconds, followed by TSRW 12 Plus and Vertglas, which took just over one minute. Foaming was a problem with both New Glass and 12 Plus; application of the latter was very tricky and we had to be careful we didn't overwork the coating. There was no foaming with Vertglas and I suspect, this is directly related to the brush applicator versus the chamois. Fortunately, foaming didn't results in a cloudy finish.
We coated each test patch with three coats, one less than the minimum recommended by the manufacturers. All three products gave a hard, like-new finish. Vertglas' high-gloss finish was superior, followed by New Glass in second place.
UPKEEP
Maintaining acrylics is similar to varnished finishes. When dirty, clean the surface with detergent or an all-purpose boat cleaner. Damaged areas are easily touched up following the same application techniques. Once a year, manufacturers recommend cleaning the surface and applying one or more additional coats as desired -- the more coats the higher the gloss -- to insure sufficient UV protection.
Neglect an acrylic coating and like any paint or varnish, it begins to break down. It turns cloudy, begins to "curdle" and must be removed entirely before applying a new coat. Unlike conventional coatings, however, you can't sand or scrape off acrylic. Removal involves soaking the surface with an ammonia-based cleaner or acrylic wax stripper and plenty of scrubbing. (Now is the time to purchase, borrow or steal a Roto Brush, if you haven't already.) Super Tuff will remove it, so will TSRW Quick Strip and Vertglas Sealer Remover, but all require lots of elbow grease.
We checked our test boat after six months exposure to the winter sun in southern Ontario. All three acrylic surfaces looked good both in gloss and appearance.