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Boat Fairing, Practical Tips to Do it Yourself | Best For Consumer

The fairing is a set of maintenance operations and maintenance to restore the hull (submerged part of the hull) to its clean and smooth original appearance. It usually includes cleaning the hull, removing marine organisms from the hull, and applying antifouling paint over the entire surface below the waterline.

The fairing not only helps to improve the appearance aesthetics of the hull but also to optimize the performance of the boat and make savings of fuel. It is also an opportunity to inspect all the live works, change the zinc anodes and possibly carry out repair work (renovation of the gel coat, change of the hydrolube ring, repair of the shaft or propeller Etc …)…

Most sailors do the refit between April and June, but I advise to do it outside these periods to have more time, more availability and to have cheaper handling rates. Doing the careening of your boat every year is a recommended practice. You can even fair a Square Stern Canoe by yourself. Let’s have a look at our Square Stern Canoe buying guide to choose the perfect one for you.

Let’s take a look at the steps to follow to carinate your boat yourself.

What you need to know before refitting your boat

The fairing releases toxic substances into the air and the water. It is almost the first source of pollution in ports. Like all the operations generating toxic waste, it is framed by the law (Code of the maritime ports, Code of the Environment, General Code of the property of the public persons, departmental health regulations … Etc.).

Before proceeding to the fairing of your boat, make sure to respect the legislation in force. The wild fairing that takes place on hold or at low tide (even with a cloth deposited under the boat) is strictly forbidden because it makes return toxic substances in the natural environment.

The fairing must be done in a fairing area equipped with all the equipment necessary to recover and isolate the waste harmful to health and the environment. Failure to re rules concerning the fairing boats in the USA can be fined 5 th class up to 1$500.

Equipment needed for the fairing of a boat:

  • Dust shield
  • Combination (liquid tight)
  • Nitrile gloves
  • Protective glasses
  • A drill
  • Paint mixer
  • A sander 
  • A high-pressure cleaner.
  • A tape masking.
  • A spatula.
  • The necessary amount of antifouling paint for the hull.
  • The necessary amount of antifouling paint for the propeller and the shaft.
  • The necessary amount of the primary.
  • The necessary amount of diluent.
  • Epoxy putty
  • Of paint trays.
  • The abrasive discs 240.
  • A cleaner for concretions
  • The anti-drip roller 180mm
  • of brushes
  • Clean rags.
  • Acetone

Prepare the hull

Once the boat is well-positioned in the fairing area, use the high-pressure cleaner to remove dirt on the hull.

Take the opportunity to clean the shell with a special foaming soap and a soft brush.

After cleaning, it is necessary to check the condition of all elements mounted on the hull: valves, sockets, shaft line, chair, cable gland, hydrolube ring, keel, propeller, saffron … Etc.

Also, check the condition of the Gelcoat. If necessary, make the required repairs.

Hide areas that will not be painted, mark the work area with masking tape.

Also clean the propeller and propeller shaft, as they must also be treated with suitable antifouling. For this, use a sprayer with the ecological anti-concretion remover. (or hydrochloric acid if you have nothing else) Leave on for 10 minutes, then start scraping. Once the concretions are removed, rinse the treated parts thoroughly. Let dry for a few hours then sand.

The sanding of the hull is necessary if you want to facilitate the hanging of the paint or if you want to decrease the thickness of the old layers of antifouling, but it is not obligatory. Use the sander and an abrasive disc 240 for uniformly sanding the hull without over-stressing to avoid returning to the Gelcoat. Also, sand the keel if you have a sailboat so that it is perfectly clean and smooth. In any case, you can sand the propeller to refurbish it before starting on a particular propeller paint cycle.

After sanding, rinse the hull again to remove dust from the operation.


To avoid having to sand the hull every time, use an erodible antifouling

Apply the primary

To begin, seal all cracks and impacts on the hull and keel with an epoxy putty like watertight for example. Sand these repairs to 240 before applying the primer.

The application of a primer is justified if the boat is new or the hull laid bare or if you do not know the previous antifouling and you have a doubt about its compatibility with the original.

Note that the primer must be perfectly adapted to the support (material composing the shell).

Mix the primer well in a paint tray using the drill and mixer. Apply the first coat of primer while crossing with the brush to distribute the paint on the surface of the hull. Let it dry for at least 4 hours, then apply a second coat of primer. Well done, the application of the introduction on the Gelcoat will allow a perfect grip of the anti-fouling paint.

What kind of antifouling?

Antifouling paint is an anti-fouling paint that protects the hull against the colonization of marine organisms such as algae and shells. There are generally four main categories of antifouling colors:

  • Hard matrix paints.
  • Erodable matrix paints.
  • I have mixed matrix paints.
  • Non-stick paints.

You will find more details in this article: Antifouling Basics

Hard matrix paints

They are more resistant because they contain binders that do not dissolve in water. They regularly release chemicals (biocides) with the capacity to destroy living organisms, including algae and microorganisms. When the amount of biocides in the paint is ultimately released in the water, the color loses its protective capacity, which facilitates the adhesion of algae and microorganisms on the hull. You should know which paint is the best paint for a fiberglass boat.

Erodable matrix paints

These paints contain soluble binders. They, therefore, degrade progressively in contact with water, which eliminates microorganisms attached to the surface of the hull. These paints are generally discouraged for boats that sail for a short time, especially those that are moored for a long time in waters subject to strong currents.

Mixed matrix paints

These are intermediate products that combine the characteristics of the hard matrix and erodible matrix paints.

Non-stick paints

In particular, silicone paints represent a practical and ecological solution for protecting the hull of a boat while avoiding the release of biocides in the water. Composed mainly of hydrogel and silicone, they give a smooth appearance to the surface of the hull and thus prevent algae and microorganisms from adhering to it.

Each type of antifouling paint has its advantages and disadvantages. To choose the appropriate color, it is necessary to take into consideration several factors such as the type of boat, the type of wintering (dry or afloat), the navigation zone (sea or river, cold water or hot water) … Etc.

How much paint do you expect?

To determine the amount of antifouling paint needed, you can use the following formula:


Quantity of paint = (hull surface x number of layers) / (hiding power x 0.8)

The hiding power is an index generally mentioned on the packaging of the painting. The surface of the hull is calculated as follows:


  • Motor-boat:  waterline x (main beam + draft) x 0,85 .
  • Sailboat with deep keel:  waterline x (main beam + draft) x 0,5 .
  • Sailboat with long keel:  waterline x (master bau + draft) x 0,75 .

For the exact painting process, you should not miss our how to paint outboard motors.

Application of antifouling

The hull must be completely dry before applying to antifoul. The paint must be fluid and homogeneous. If necessary, use a suitable thinner, but avoid acetone and white spirit, mainly as they affect the protective properties of biocides.

Spread the antifouling with the roller in the same way as for the primary to cover the entire surface of the hull. Always finish in the direction of water flow to promote sliding. For difficult areas, use a paintbrush. Let dry for a full day, then apply a second coat.

Also treat the propeller and the shaft with a suitable antifouling such as Velox for example, while making sure to hide the intended location for the anode. Antifouling based on copper thiocyanate seems to give good results on aluminum elements and reduce the risk of galvanic corrosion. Once the operation is complete, remove the masking tape from the hull and shaft, and mount the new anodes.

Return the boat to the water

Before returning the boat to the water, it is essential to let the dry antifouling well to guarantee its adhesion to the hull and its longevity in time. It is also necessary to re-check the condition of the valves, glands, and hulls. As with the water outlet, care must be taken to return the boat to the water and take all necessary precautions to avoid damaging the sensitive elements.

Practical advice to successfully refit your boat

  • Always adjust the pressure of the pressure washer to ensure effective cleaning while avoiding damage to the Gelcoat.
  • Be sure to position the masking tape as accurately as possible on the waterline to avoid damage to this susceptible area.
  • Do not hesitate to add a third layer of antifouling on the areas most exposed to soiling including the waterline (40 to 50 cm), keel, bow, and saffron shovel.
  • If you are using an erodible matrix paint, consider using different colors to differentiate the layers. This allows you to assess the degradation status of the antifouling accurately.
  • To avoid premature degradation of antifouling, consider storing your boat in a space on land when not in use.

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