It's a well known fact that all GRP gelcoat surfaces will benefit from at least one application per year (or preferably 2) of a good quality wax such as Meguiar's Flagship Premium Waxwhich not only seals the surface from ingress of dirt but also protects against UV degradation. To get the best result and protect your investment, we recommend that you first wash the surface down to remove any surface contaminants. I always use and recommend Yachticon GRP supercleaner. If after carrying out that task, you then discover you have some minor gelcoat damage that requires attention, now is the time to tackle this.
For those annoying unsightly hairline cracks (often found round stanchion bases) MagicEzy Hairline fix is the business! It's great for stress cracks, crazing and scratches. For best results, first scrape out any dirt/wax/grime with a sharp needle/pin. In our experience, simply washing the area is not as effective. It's worthwhile also flushing the surface to be treated with acetone. Use MagicEzy 9 Second Chip Fix for ‘sorting’ nicks, chips and gouges. This excellent product is available in 11 colours (inc five shades of white).
For larger dings that you may want to tackle, we suggest you clean the immediate area with 1200 wet/dry paper. This will remove any oxidised gelcoat still remaining, without doing this your repair will end up having a miscoloured ring round it. Getting the correct coloured gelcoat can be a pain, however we always recommend in the first instance you contact the original boatbuilder or importer of the boat whilst armed with the hull build number to see if they can supply. Once you have ascertained the correct match and prepared the surface to accept ‘catalysed’ gelcoat, apply with a soft brush leaving the material slightly proud. Carefully apply a piece of clear Sellotape or cling film over the gelcoat, this will prevent the gelcoat drying tacky. When set remove the tape and carefully sand to shape using a sanding block with 400 then 600 and finally 1200 wet/dry paper and plenty of water. Do this carefully so as not to damage or rub through the surrounding gelcoat. The repair can then be polished to a mirror finish using Farecla or a similar compound and then to seal the surface a good quality wax polish such as 3M marine ultra performance wax.
After the wash down we recommend that you use a mild cleaner such as Meguiar's Colour Restorer which will safely remove light oxidation and most stains from the gelcoat either by hand or machine. By using a machine to do the hard work the task will be completed quicker than buffing by hand using a 100% cotton polishing cloth. If using a machine we recommend a variable speed machine like the Shurhold Dual Action polisher with either a microfibre or foam polishing bonnet. Keep the speed slow and don’t stay in one area as it is all too easy to overheat and damage gelcoat. Don’t be tempted to use an electric drill with a polishing bonnet, they are usually too high a speed and can result in burn damage to the gelcoat. If there is no power available, the OrbiPro Cordless Orbital Tool is a useful investment, particularly as you can rent it to your neighbours when they see the fabulous finish you have achieved.
An oxidation remover will bring life back into a hull, however, if the topsides are very chalky and dull (dark green & blue gelcoat are particularly susceptible) you can start with a coarse paper 200-300 working up to 800 or 1000 grade, or after using the more aggressive grades spread compound evenly onto the hull in areas of about a square metre so it doesn’t dry. Work with the polisher in lines. While working, don’t place your polishing mop on the ground or on the plank you are working on; one speck of grit on its surface can have disastrous results on your topsides! When applying cleaner or oxidation remover always work on a cool surface in the shade.
BRIGHTENING AND RESTORING YOUR TOPSIDES
Don’t try to polish or wet/dry rub down rust or black berry bird droppings marks from your decks or hull, the stains can be deep into the gelcoat. Instead try using a stain remover based around oxalic acid such as Y10 or Davis FSR, either should bleach out the stain. After thoroughly cleaning with either the mild cleaner or the oxidation remover the surface must then be sealed using a good quality uv resistant wax, for best results apply at least 2 coats with a day between each coat to allow the wax to harden. Applying the second coat too soon will only remove the first! For GRP cabin sides and other smooth gelcoat surfaces the technique is the same, however for cleaning and removing oxidation on moulded in nonslip I always use Vistal Hard Surface Cleaner. Vistal can also be used to help bring a sparkle back to dull painted or varnished surfaces; its also great for brightening your stainless pull/pushpit, alloy stanchions other metal surfaces and of course fenders.
Teak decks can suffer badly in our damp climate growing algae and moss during the winter months and I have no doubt that boats in other locations suffer similarly. Whatever you do, don’t be tempted to clean them with a pressure washer. They will certainly be clean but the pressure of the water jet will tear out the soft grain leaving them like a ploughed field. It is best to clean them with one of the proprietary teak cleaners my choice being Teak Wonder cleaner, however we all tend to have our favourites.
Anyway following their instructions, use Starbrite Magic Scrub and, for the awkward corners, a stainless bristled Detailing Brush or a Shurhold Scrubbing Pad and ONLY scrub across the grain. After cleaning, the decks should be given a wash with Teak Wonder brightener, this will restore their colour. When dry, spray with ‘Wet and Forget’ which will stop any moss or algae growth.
LAST BUT NOT LEAST
Should you have halyards, webbing lifelines and other items that are resting on the deck and have turned green over the winter months don’t despair. Don’t get the pressure washer out (destroys stitching/fabrics etc) but spray Wet and Forget on these items and leave. The 5:1 diluted solution will do all the hard work and prevent re-growth. If any covers, dodgers or spray hoods are also looking green they will also benefit from a spray of the same solution. Once the green has gone (may take a few weeks depending on the weather) wash with fresh water, allow to dry and then proof with Graingers Gold, not only will the water bead and run off instead of soaking in but it will help repel surface contamination.