Installing A Fuel Tank In An Aluminum Boat: A Step-By-Step Guide

Aluminium is often blamed for being a poor material for fuel tanks, but this is not true. All materials have their strengths and weaknesses, and when it comes to aluminium tanks, the problems lie with improper installation rather than the material itself. Properly installed aluminium tanks will usually outlast the life of the boat. This article will provide a step-by-step guide on how to install an aluminium fuel tank in an aluminium boat, covering topics such as preparing the boat's surface, positioning the tank, and sealing and securing the tank to prevent corrosion and leakage.

How to Install a Fuel Tank in an Aluminum Boat

Set and glue the tank on top of plastic strips

To set and glue the tank on top of plastic strips, you will need to use 1/4" strips of plastic that are about 2" wide and spaced about every 12" apart. Haysite or any fibre-reinforced plastic sheet will work for this. Cut the strips to a length exactly 1/4" shorter than the width of the tank so that they don't stick out the sides and collect water.

Next, use at least two tubes of 3M 5200 adhesive to glue the plastic strips to the bottom of the tank. Apply the adhesive so that the entire surface of the plastic is coated and there are no gaps or crevices for water to get into. Press the strips into position, ensuring that the ends are equally 1/8" from the edges of the tank. Wipe off any excess adhesive, making sure that the joint between the tank and the plastic strip is completely sealed. Don't leave any globs of material.

Allow time for the adhesive to set up

When installing an aluminium fuel tank in a boat, it is important to allow time for the adhesive to set up. This is a crucial step to ensure the tank is securely installed and to prevent fuel leakage. The recommended time for the adhesive to set up is 24 hours. During this time, the adhesive will cure and form a strong bond between the tank and the mounting surface.

It is essential to follow the manufacturer's instructions for the specific adhesive being used, as different adhesives may have varying curing times. In some cases, the curing time can be affected by environmental factors such as temperature and humidity. Therefore, it is advisable to consult the adhesive's technical data sheet or seek guidance from a marine professional to determine the optimal curing time for your particular installation.

While waiting for the adhesive to set up, it is important to avoid any disturbances or adjustments to the tank's position. Any movement or adjustments after the tank has been set in place can compromise the integrity of the adhesive bond. It is crucial to ensure that the tank is correctly positioned and secured before the adhesive cures completely.

Once the adhesive has cured, it will create a strong and secure bond between the tank and the mounting surface. This bond will be able to withstand the weight of the fuel and the movement of the boat without compromising the seal. A properly installed aluminium fuel tank will provide a safe and reliable fuel storage solution for your boat.

Apply beads of adhesive to the plastic strips

To apply beads of adhesive to the plastic strips, start by acquiring at least two tubes of 3M 5200 adhesive. This adhesive will be used to glue the plastic strips to the bottom of the tank.

Apply a generous amount of the 3M 5200 adhesive to the entire surface of the plastic strips. Ensure that there are no gaps or crevices left uncoated, as these could allow water to get in and cause corrosion. The plastic strips should be coated with an even and thorough layer of adhesive.

Once you are satisfied with the adhesive coverage, carefully press the plastic strips into their designated positions on the bottom of the tank. Make sure that the ends of the strips are equidistant from the edges of the tank, with a spacing of approximately 1/8" on each side.

After the plastic strips have been secured, use a clean cloth or tissue to wipe away any excess adhesive that may have squeezed out. It is important to ensure that the joint between the tank and the plastic strip is completely sealed and free of any adhesive globs or residue.

Position the tank carefully

Positioning the tank carefully is crucial for a successful installation. First, ensure the tank is set on top of 1/4" plastic strips that are approximately 2" wide and spaced about every 12". Haysite or any fibre-reinforced plastic sheet is recommended for this. Cut the strips to a length that is exactly 1/4" shorter than the width of the tank to prevent them from sticking out and collecting water.

Next, apply a generous amount of 3M 5200 adhesive to the plastic strips. Make sure to coat the entire surface of the plastic with the adhesive to avoid any gaps or crevices that could trap water. Once the strips are pressed into position, ensure that they are evenly spaced from the edges of the tank.

After allowing 24 hours for the adhesive to set, it's time to apply two 1/4" wide beads of 5200 along the length of each plastic strip. This will help secure the tank in place. Be careful not to fully bed the strips, as the tank expands and contracts when filled and emptied.

Finally, with two people carefully lower the tank into place. Use wood shims to guide it into the correct position if necessary. The weight of the fuel will hold the tank in place, and the strong adhesive will create a tight seal.

Avoid using rubber strips

When installing an aluminium fuel tank in a boat, it is important to avoid using rubber strips. This is because rubber contains carbon, which is cathodic to aluminium and will cause galvanic corrosion.

Instead, it is recommended to use plastic strips, such as those made from Haysite or any other type of fibre-reinforced plastic sheet. These strips should be cut to the exact length needed, placed transversely to the length of the tank, and glued to the bottom of the tank using a strong adhesive like 3M 5200. This will ensure that there are no gaps or crevices for water to get into, which could lead to corrosion.

Another option is to use neoprene, which does not contain carbon and is a good material to use as mounting pads. However, it is important to ensure that there are no voids or crevices between the neoprene and the tank to prevent water from getting in.

Additionally, it is recommended to only use stainless steel pipe fittings for the fuel supply and to avoid mixing a variety of metals. The tank should be placed on a stable surface, such as the hull stringers, and not directly on the bottom of the hull. This will help to prevent crevice corrosion and ensure the longevity of the fuel tank.

Frequently asked questions