How to Paint Aluminum Boat – Guide

What is better an aluminum boat or a fiber boat? This is a regular question with no easy answer. Both aluminum and fiber have their advantages and disadvantages and depend largely on the size and use we will give our boat. In this post, we will talk about everything about the aluminum boat. But especially Aluminum boat paint guide.

Aluminum is twice as strong as fiberglass, four times stronger than ABS thermoplastic, and as much as ten times stronger than marine-grade plywood.

Aluminum vs Fiberglass Boat

Pros and cons of aluminum boats versus fiberglass boats.


Aluminum boat hulls are much stronger than fiberglass boats. In general, aluminum allows us to make stronger structures with equal weight. An aluminum boat is much more robust and its structure is more rigid, so an aluminum boat will resist better blows and rubbing. In the event of an impact, the aluminum will bend while a fiberglass boat will break, as long as it is not a very violent or large blow. Aluminum has a great ductility or capacity to support permanent deformations without breakage and in this way, an aluminum boat can be beached on a beach resisting well the frictions of these abuses. The greater structural rigidity of aluminum boats, since they are built by welding all their structural parts, makes them good boats to withstand hard sea conditions.

Aluminum hulls, if the proper alloy is used, resist saltwater corrosion better than steel boats and do not require any special painting. They also suffer from galvanic or electrolytic corrosion which can be avoided with a well-insulated electrical installation and the use of sacrificial anodes. Fiber boats do not suffer the effects of corrosion, although they can be affected by the phenomenon of osmosis and suffer from the ultraviolet rays of the sun.

2.- The Weight

Aluminum is a lighter material than fiber, which makes it a lighter boat, therefore it will be a faster boat and will need less engine to move the same meters as a fiber boat, which also leads us to a lower consumption boat.

3.- Operability

Fiber boats, being heavier, are also more stable and solid at high speeds, and when the sea state starts to get rough and complicated. An aluminum boat at high speeds can feel more nervous and rougher with rough seas.

4.- Comfort

Aluminum boats are noisier than fiberglass boats, especially at high speeds and in rough seas. Aluminum is a better transmitter of temperature and therefore if not well insulated in its construction with a thick layer of polyurethane or other insulation, it will be hotter in hot places and colder in the winter. These boats also suffer more from condensation problems than fiber boats. Therefore, a fiberglass boat can be somewhat more comfortable than an aluminum boat.

5.- Maintenance

Aluminum boats due to corrosion require more maintenance, a problem to be monitored is the galvanic pairs of material, corrosion effect that occurs when parts of different metals are joined together. We must be careful with the quality of any part or screw we use because it could cause us a serious problem. We must also clean the boat well with fresh water after each use.

Fiber boats do not have rivets, welds, or corrosion to worry about, although we must watch every year possible osmosis problems that if not treated in time can cause serious problems, anyway, osmosis problems with new resins have been mitigated quite a bit compared to hulls of 20 or 30 years ago. Anti-fouling, which is a paint given to the boat’s hull to prevent different types of algae, limpets, and snails from being embedded in the hull, is much more expensive for aluminum boats than for fiberglass boats.

6.- Repairs

Small dents on an aluminum boat are easy to repair but when the damage is over large areas of the hull, repairs are more difficult and expensive than on fiberglass boats. Aluminum welding is a very specialized and complicated job, finding professionals trained to repair fiber is easier and cheaper. However, a large, partial repair on a fiber hull does not guarantee the original strength as the structural tension will no longer be the same at all points.

7.- Security

Fiber boats are built with petroleum products and are therefore combustible. Also, in case of an impact with a rock, it is easier to make a waterway in a fiber boat than in an aluminum one.

8.- Residual Value

The wear and tear of a fiber boat are greater over the years, exposure to sunlight and osmosis do not affect aluminum boats. They also resist better the incrustation of algae and marine crustaceans. The greater rigidity and structural strength also make aluminum boats stand up better over the years and because of this, they depreciate less than fiber boats.

How to Clean Aluminum Boat

The best way to clean an aluminum boat is with bleach. Take your boat out of the water and Dry Dock away from lakes or rivers, as bleach can kill marine life and damage a lake or river ecosystem.

Wear a pair of latex safety gloves. Remove all large pieces of debris, algae, and dirt by pulling it away from the boat. Dispose of this debris in the trash.

Scrape off any barnacles, large clumps of algae with a spatula. Take the latex gloves and put them aside.

Clean the whole boat with water jets with a hose. Alternatively, fill a bucket with water and clean the entire hull with a sponge.

Put on old clothing, safety glasses, and latex gloves. Bleach can damage the eyes and skin and will leave permanent stains where clothing comes into contact.

Mix hot water and bleach in a 4 to 1 ratio in a bucket. Immerse the nylon brush in the water and then brush an area of the hull in a circular motion until you have removed any algae build-up from the hull. Repeat this process on other sections of the hull until you have removed all algae from the boat.

Immerse a cloth in the bleach solution from the water and wipe a section of the boat in a circular motion until you have removed any discoloration from that section.

Clean the entire hull of the boat with clean water to remove any bleach residue. Long term exposure to bleach can cause aluminum to oxidize, leaving a whitish crust or dye on the surface.

aluminum boat beach

Aluminum Boat Repair

Aluminum boats can withstand great abuse without suffering any serious damage. However, if a leak occurs, an uncomfortable or even dangerous situation could arise. Repairing aluminum boats is easy as long as the cut or hole is no more than 1 inch in diameter.

Locate the exact source of the leak. Place the boat in the water with the inside dry. Find the place where the water is entering. You may need the help of friends to detect the leak.

If you cannot find the leak using the first method, place the boat on a trailer, sawhorse, or other raised support with an open area underneath. Fill the boat with water until you can see where the leak is located.

Mark where the water is entering the boat, both inside and out, with paint or tape. Then clean the surface of the aluminum thoroughly.

Apply 3M 5200 sealant to the area of the leak. Apply it to both the outside and inside of the aluminum canister to ensure a good seal. Open the tube of sealant and apply it as if it were putty.

Use a putty knife to smooth sealant over the area of the leak. This will form a durable seal that should hold up well for several years. Allow it to dry and cure completely before putting the boat in the water.

Warnings: If there is a crack or hole in the aluminum boat larger than 1 inch in diameter, you should take it to a soldering warehouse for a solid repair.

Aluminum Boat Paint

The trick to painting aluminum is in the preparation. A clean surface and proper materials are the keys. Aluminum boat paint step by step.

aluminum boat

Steps to follow:

1- Place the aluminum boat on the two stands. Getting the boat up allows you to work around the boat much better than you could on the ground. The initial position of the boat on the racks is not important, although it may be easier if the bottom of the boat is on the racks, with the inside of the boat facing up.

2- Sand the boat completely. This step is necessary only if you would repaint an aluminum boat that had a previous coat of paint. You can do this with a block of wood and a sheet of regular sandpaper, but the most effective method is to use a power sander. Sand the entire boat, inside and out. Don’t worry if you can’t remove 100 percent of the paint. And don’t worry about scratching the metal with the sander, because these scratches will be invisible later and provide a larger surface for the paint to adhere to. You may find it easier to sand the inside of the boat first, then sand the boat on the outside on the trestles.

3- Wash the boat. Fill the bucket with soap and water, and use a stiff-bristled brush to scrub the boat down. Scrub the boat as hard as possible to remove sanding residue. Rinse the boat with a water hose, preferably one with a feed nozzle. Allow the boat to dry completely

4- Put paper or plastic on the floor in your work area. Anything that can be damaged by paint should be removed from the immediate area, and other objects should be covered by paper or plastic. Open all available windows, and use electric fans to provide ventilation.

5- Apply a primer to the boat. For best results, use an oil-based primer made to be used on metal. You can lighten the primer by mixing one liter of paint solvent in one gallon of primer. You can use brushes or rollers, but you will get a cleaner and more even finish if you use a paint sprayer to apply the paint. Start spraying the interior of the boat, allowing it to dry, then turn the boat to apply the primer to the exterior. Allow the primer to dry several hours before starting to paint.

6- Paint the aluminum boat in the color of your choice using waterproof paint. Again, it will be much easier to paint the first half of the boat, let it dry, then turn the boat to paint the other half. You may have to apply two coats to get the desired color. Allow the paint to dry completely.

7- Apply a transparent layer. The varnish is sprayed on the boat in the same way as the primer and paint. The clear coat provides protection from the elements and from scratching and will give the boat a freshly painted appearance. But it will also make the boat a bit shiny, so you might skip this step if you are going to use the boat for hunting.

This is all about “Aluminum boat paint”. If you are going to go fishing with your boat do not forget to get your fishing license.