Press Article - Practical Boat Owner

10 gelcoat cleaners Which gelcoat cleaners are best at combating waterline yellowing on boat hulls? Ben Meakins dons his rubber gloves and puts 10 products to the test Gelcoat is an amazing material – hard-wearing, easily repairable and eminently restorable – but as it gets older it becomes porous and starts attracting stains. Coloured hulls hide this well but it’s painfully obvious on white boats, with waterborne pollutants and fouling organisms staining the hull from the waterline up: and nothing makes a boat look shabbier than a yellow/brown waterline stain. Luckily for us , there are few more satisfying jobs than removing such stains when you use the right tools. Even better , for once in boat ownership it doesn’t require much elbow grease. Instead, a chemical reaction does the job for you. Chandlery shelves groan under the weight of treatments. Most contain oxalic acid, with some supplied as a liquid and others mixed with a gel to help them stay in contact with the hull as long as possible. There are other acids which will remove the staining, and some people even claim that lemon juice, if left long enough, will help. However, not all acids will leave the gelcoat untouched, so it’s worth using products that are certified safe for boats. Have a look at the label –although oxalic acid is the most common active ingredient, citric acid and phosphoric acid are used in some products. Online advice suggests buying a tub of oxalic acid powder and mixing it with wallpaper paste to make your own treatment, but the potential for health issues means we’ve limited this test to products commercially available in the UK. As with any chemical reaction, the results will improve the warmer the temperature (as long as it doesn’t dry out ) – and Y10, for instance, claims improved results above 10°C. Our test day in February had colder temperatures of around 6-8°C, so we left the products on the hulls for the longest time specified on the containers. As we were testing the products, a local professional walked past and proffered his own ‘home – brewed ’ potion, which as far as we could make out was hydrochloric acid. This smoked horribly when applied, caught the back of the throat and felt very dangerous, but it cleaned up the gelcoat visibly faster than the others on test. However, splashing hydrochloric acid around is dangerous – damaging to skin, respiratory systems and the environment – so it can’t be recommended. How we tested them. We borrowed Barney Smith’s Impala 28, Imptish, which, after a busy season moored on the Hamble River had a heavy brown waterline stain along her 30-year-old white gelcoat. With the boat out of the water at Deacons Boatyard, we cleaned off the hull with fresh water before drying it off and taping out a test panel on the starboard side, with strips between left untreated to show the hull’s condition before the test. We applied each product to its panel according to the instructions on the bottle, leaving it on for the maximum time specified before rinsing off and comparing the result with the surrounding areas. Grunt!Boat Cleaner PRICE: £22.45/1LT Contact: www.gruntboatcleaner.co.uk Grunt! Boat Cleaner contains no oxalic or hydrochloric acid, instead containing phosphoric acid (also found in Coca-Cola), and is thus said to be biodegradable and safer to use. It is painted on and left for 30-60 minutes before being washed off. This had to be left on for the longest time of the products tested, but upon rinsing off left the hull as clean as the top tier of products save for the heaviest staining. However, as we tried this one at the bow where the staining was worst, that was to be expected. A second application saw to the remaining stains.
Boat Buddy Gelcoat Stain Remover PRICE: £21.91/1LT Contact: www.boatbuddy.org.uk Boat Buddy Gelcoat Stain Remover is sold as a second-stage product in an eight-stage cleaning system. It’s a similar formulation to Grunt! Boat Cleaner, and, as with that product, it’s designed to be brushed on, left for 30-60 minutes and then washed off. It left the hull in a good condition, bright white, with the worst areas requiring a second application
PBO verdict As expected, all the products we tried improved the hull’s colour significantly. There were a few products which gave ‘top tier’ performance, however – Y10, Star brite Hull Cleaner, Silky Marine Bright and Chine Shine gave the best results in the fastest time. In the next tier, very nearly as good, were Grunt! and Boat Buddy, which delivered equally good results after a longer time. Next up, International’s Stain Remover, Hempel Gelcoat Cleaner and Farecla’s Rapid Stain Remover performed well but required a second application on stubborn areas. As all the products except Meguiar’s No49 contain some sort of acid, be it oxalic or phosphoric, it’s not surprising that the results were all very similar. However, differences lie with the concentration of the acid and the makeup of the gel or liquid in which it’s suspended. Gel has the advantage that it ‘clings’ to the hull and keeps the acid in contact for longer than a thin liquid which can run off – meaning you also use less. Prices varied considerably. Chine Shine gave great results for the lowest cost per litre (although it’s only available in sizes from 2lt upwards), with Silky Marine Bright also coming in cheaply. Y10’s gel format gave great results in a short time.