The top coating of your fiberglass boat, also called a “gelcoat”, will remain shiny as long as it is regularly cleaned, polished and protected from the sun. If the dead works of your boat are tarnished or discolored in places or if the gelcoat has become porous due to bad weather, know that it is possible to polish them to restore their shine. It's a fairly straightforward operation, much like polishing a car. Each sailor has his own way!
Steps
Part 1 of 3: clean your boat

Step 1. Secure your boat to its trailer
The waxing is done when the boat is on dry land. It is best to leave it on its trailer, securely attached, preferably on a level surface. As you will have to go around the boat several times, the trailer must be detached from the towing vehicle.
Depending on the profile of your boat and the parts to be treated, it may be necessary to protect certain parts. If possible, put or leave the tarp in place, at least to protect the interior

Step 2. Hose clean the exterior of the boat
Buffing a boat always starts with a good cleaning. Remove any dust and any dirt that may have settled. Remove algae and moss.
- Start by washing the entire surface to be restored with clean water. To do this, use a large clean sponge and rub moderately, insisting on the dirtiest areas. Remove as much deposits as possible.
- If in some places the dirt is particularly encrusted, do not hesitate to use fine grit sandpaper (220). Do not use a pressure washer as the water pressure can affect the gelcoat! The water jet from the hose should not be strong.

Step 3. Remove, if there is any, the old wax
In this case, use a cloth impregnated with toluene or a wax cleaner. Thus, you can then, with a polish or polishing paste, homogeneously clean the surface to be treated.
Clean by moving your cloth always in the same direction and without pressing too much. It is not useful to rub hard. Once the job is done, wait for your product to evaporate before polishing

Step 4. Clean with a suitable detergent
Finish cleaning with a sponge and boat detergent. You can also use hot water with washing up liquid.
- If your boat is stained, you can use (with care) a little bleach, to apply directly to the stains. Some also use varnish thinner or a degreaser to remove glue residue (adhesives) or grease stains. On the other hand, it is out of the question to use bleach on raw or unvarnished wood.
- Rinse the boat with clean water and dry well. To remove the remaining water, you can use a squeegee.
Part 2 of 3: sand the entire surface of the boat

Step 1. Optionally use a polish or polish
Polish and polish are both slightly abrasive, which is what allows a boat's gelcoat to regain its shine. Abrasion helps reduce imperfections, haze, discoloration spots and microcracks.
- The polish should rather be reserved for a boat which would only require a slight refurbishment of the gelcoat. On the other hand, if your dead works have become porous, covered with a kind of thick veil, use a slightly more abrasive polishing paste instead.
- Be careful when using polishing paste. Indeed, the gelcoat is a coating, certainly hard, but very thin. If you polish it too much, it will disappear completely and you will have to put gelcoat back on, a delicate, long and expensive operation.

Step 2. Start at the stern and work towards the bow
Apply the polish or the polishing paste in square sections of 50 cm on the side. Use a soft cloth if you are doing this by hand. If you are using an electric polisher, take a foam pad. Apply wax to the cloth or pad and run it across your surface in a regular circular motion. Buff until the surface becomes hazy. If you gloss too much you'll see through the gelcoat and that's no good!
- Purists swear by hand polishing, others prefer to use a polisher which saves time and avoids fatigue by eliminating gelcoat defects more easily. Use a slowly spinning polisher, rather than a regular sander that spins too fast. Orbital polishers are particularly effective for this kind of work.
- Your polisher will be set to the lowest speed. Before operating, lightly apply your tampon on the surface of the boat to distribute a little paste. Thus, there will be no side projections.

Step 3. After the polish paste, apply a polish
If necessary, do the same with a suitable polish. Always work in circular motions and always in the same direction as with the polishing paste. Spray the treated surfaces with a jet of water to remove all traces of polishing and product.
Part 3 of 3: polish the boat

Step 1. Purchase a wax suitable for your boat
Indeed, there are various types of wax depending on the type of gelcoat in place. Waxing the gelcoat helps it retain its shine longer, as the wax acts as a barrier between the gelcoat and water.
There are many brands of wax: “Collinite 885” is often used for boats, but also for surfboards and other gliding elements

Step 2. As with polishing paste, spread the wax in a circular motion
As with polishing and buffing, you can apply wax by hand or with an electric polisher. To avoid scratches, work in circular motions.
There are many, many boat waxes. Ask the dealer for advice

Step 3. Be very careful in delicate areas (fittings, recesses)
These junction areas must be treated by hand so as not to damage these parts in contact with the gelcoat (such as the rubbing strake). Do the same with the recesses, such as the through-hulls.
If possible, remove a particular piece of hardware. Keep the parts in question and their fixings together, so that you can reassemble them later

Step 4. Let the wax dry well
After a few minutes, the wax has a slightly whitish appearance, a sign that you will be able to shine. It is important to let the wax dry well and give it time to soak up the porosities of the gelcoat. Allow 5 to 10 minutes in the sun.

Step 5. Carefully polish the waxed parts
Use a soft cloth or a buffing cap (if using an electric polisher). Work in very light circular motions. The more you scrub, the more the waxy veil will disappear, the more your boat will shine.
Advice
- If you don't have the time or the courage to polish your boat yourself, have it done by a specialist. In the vicinity of your anchorage you should find one. There is no need to hire a bodybuilder since the polishing of a boat, because of the differences in gelcoat, has nothing to do with that of a car.
- Some boat owners who know about it claim to carry out, before applying a polish or a polishing paste, a certain number of sandings (with water), each time with an increasingly fine abrasive.