Steps in Boat Painting

Boat Painting is an important aspect that boosts its aesthetic and resistance. Unlike cars, boats are exposed to harsh weather conditions that can easily erode paint finishes. For this reason, a regular maintenance job is recommended. In particular, knocks and chips should be dealt with quickly to prevent water from seeping under the loose paint and damaging the structure underneath.

The first step in boat painting is thoroughly cleaning the hull’s surface. This is best done shortly after the boat is removed from the water and should involve a high-pressure hose, scraper and rags. Removing slime, sand, dirt and any hard growth will ensure that the paint adheres well and will look good once it is dry. If there is rust on the boat’s surface, it will need to be sanded off to give a smooth base for the primer and then the finish paint. If this is necessary, it may be worth bringing in a power sander with a variety of grits to get the job done properly.

Marine paints contain chemicals that help them stand up to the harsh conditions of the water. However, they can still suffer from the same effects as any other paint when exposed to sunlight for long periods of time. This is why it is important to add a UV-light protection additive to the marine paint before you apply it. The additive will keep the paint from fading or chalking due to sun exposure.

Generally, it’s recommended to apply two coats of primer. This will allow the primer to fully dry in between, preventing any cracking of the surface underneath the final paint. This can be a painstaking process, but it will be much easier to paint over the top of a cured primer than a fresh layer of paint that has not fully dried in between applications. As the primer is drying, it is a good idea to cover any areas that you do not want painted with painters tape. This includes thru-hull fittings, eyes and other hardware on the boat.

Even with the best care, a boat needs to be painted at least every two decades. A fresh coat of paint can keep the hull looking great and extend its life. This is why it’s important to choose the right paint and to prepare the surface carefully.

If you are painting over a previous layer of topside paint, be sure to follow the manufacturer’s instructions. This usually includes dewaxing the substrate and sanding it smooth. Some paints also require wiping the surface with a solvent to remove grease, wax and oil. You may also need to add a rust inhibitor to prevent future corrosion.

You’ll need to clean the entire surface of the hull before you can start painting. This can be a time-consuming task, but it’s necessary to get the best results. Use a high-pressure hose and rags to wash the hull as much as possible, paying special attention to areas where seaweed or sand have stuck. If you need to, use a scraper or brush to get rid of hard stains and patches.

When sanding the surface, be sure to use a power sander with varying grit levels of sandpaper. This will create a smooth, consistent surface and help to prepare the boat for the next step in the process. If you have rusty spots, be sure to sand these down as well.

Finally, if your boat has a gelcoat, consider using a product to protect the gelcoat from UV light. This will prevent the hazing of the gelcoat and give the paint a longer lifespan.

A primer is used to prepare a surface for painting and help it adhere. Most paint manufacturers will provide their own recommended primers for their respective products. Each of these primers has a different function and each is formulated for specific use with their product line.

For example, one primer may be formulated to work with yacht enamels or other 1-part paint systems. This type of boat primer is good for do-it-yourselfers because it dries quickly and is relatively inexpensive. Another type of primer is a 2-part epoxy or polyurethane primer that provides a hard base for epoxy and polyurethane topcoats. These types of boat primers are more difficult to work with, but they provide a superior finish with a high gloss that lasts.

Depending on the type of primer you select, you will want to follow the product guidelines carefully. Many primers will list the type of paint they are designed to work with, so don’t mix and match brands unless directed to do so. You will also find that most primers have a time window within which you must complete the painting process.

Once you’ve selected a primer and followed the instructions, it’s time to start applying your paint. Be sure to tape off areas you don’t want to paint or could drip on. This is especially important when working on a trailer boat, where water and grime can accumulate in the nooks and crannies. Then, sand the area with 320 grit sandpaper or a DA (dual action) sander to remove any oxidation and rough up the surface.

After sanding, wipe down the hull and apply the primer. Remember, you will need to overlap each painted area by at least three inches. Roll first and then tip with the brush as you move down the hull. As you move along, drag the brush from the newly painted area onto the adjacent previously painted areas to help eliminate any runs in the product. Allow each coat to dry a minimum of overnight.

A wide variety of bottom paints are available to prevent marine growth on your boat, including ablative, hard modified epoxy, copper-leachable and soft or sloughing antifouling. Most bottom paints contain biocides that prevent barnacles, zebra mussels, weeds and slime from attaching to the hull. If you keep your boat in the water year round, a hard modified epoxy with a high copper content is an excellent choice. This type of bottom paint releases the biocide at a controlled rate, which reduces the need for scrubbing and sanding at haulout.

Copolymer ablative paints, such as West Marine PCA Gold and Interlux Micron CSC, are another popular option. They also offer multi-season protection because they erode and expose new biocide at a constant rate as the paint wears, but without losing their antifouling effectiveness. These types of bottom paints also do not lose their ability to protect the hull while the boat is in dry storage, allowing you to skip a year of repainting at haulout and still be ready to launch in the spring.

Soft or sloughing antifouling paints like West Marine Slough Away and Interlux Alumaspray Plus release their biocide by wearing away, or “ablating”, over time, which means that they need to be scrubbed or lightly sanded prior to being put back in the water. Sloughing antifouling paints are not recommended for aluminum boats, since they can release cuprous oxide and cause galvanic corrosion. However, there are aluminum-safe ablative paints that use zinc, copper or non-metallic agents such as ECONEA. These are the best choice for aluminum hulls and underwater metals such as shafts, struts, props and keel coolers. These types of bottom paints typically require only light scrubbing or sanding, but they do not have the longevity of hard modified epoxy paints.

Once you have the hull painted and the undercoats are dry, it’s time to apply the topcoat. The topcoat gives the whole boat a deep shine and protects the paintwork from the elements. Depending on the type of finish you want, there are many different types of marine topcoats to choose from.

One of the most important things to remember when applying a topcoat is that it must be applied over a fully dried and completely degreased surface. Any impurities can cause the topcoat to bubble and look rough or sag.

For this reason, it’s important to thoroughly wash down the hull with boat soap and use a Scotch-Bright pad or Better Boat boat eraser (Check Price on Amazon) to remove any wax build up. The same goes for your work area; it’s best to spray down the area several times during the painting process to keep airborne dust to a minimum.

Once the surface is clean, the best way to apply a topcoat is with a roller using a short foam roller sleeve. It’s also a good idea to apply several lighter coats than just one thick layer as this will help to reduce the chances of runs or sags in the paint.

We recommend using Teamac’s single-pack marine gloss as it dries to a tough, durable finish and is available in over 50 colours. It can be applied over Teamac’s Marine Undercoat, but is also compatible with most other one-pack marine paint systems. Alternatively, Epifanes Yacht Enamel is another option for a high quality and well-priced finish that can be used with brush or roller.

For two-part products, it’s essential that you follow the manufacturer’s instructions exactly. These can be very precise and if any previous layers of paint are present, you must strip back to the bare substrate using either acetone or a dedicated wax-stripper. Once the paint is re-applied, it’s a good idea to allow it to dry for up to three weeks before using the boat.