The Ultimate Guide To Redecking Your Aluminum Boat

Redecking an aluminium boat is a complex process that requires careful planning and execution. One of the key considerations is the choice of material for the new deck. While some boat owners prefer to use aluminium for redecking, others opt for wood, specifically plywood. The type of wood and its treatment are crucial, as pressure-treated wood can corrode aluminium hulls and fasteners due to the presence of copper in the treatment process. Epoxy resin and fibreglass are often used to seal wooden decks, providing waterproofing and durability. Additionally, the deck design and attachment method are important factors, with some opting for removable decks that are easier to clean and maintain. Overall, redecking an aluminium boat involves a range of factors that must be carefully considered to ensure a successful outcome.

Using wooden decks on aluminium boats

Materials

When choosing the wood for your boat, avoid using treated lumber, as this can chemically react with the aluminium. Pressure-treated wood contains copper, which can cause the aluminium to corrode. Instead, opt for plywood, which can be sealed with epoxy resin. You can also use simple outdoor stock plywood, which is lightweight and will not break the bank.

Waterproofing

To ensure your wooden deck lasts, it is important to waterproof it. You can do this by applying a coat of epoxy resin all over the wood. For extra protection, you can add a thin layer of fibreglass to the top surface of the deck. This will seal in the resin and provide a durable finish.

Fasteners

When it comes to fasteners, avoid using galvanised steel, as this will also react with the aluminium. Instead, opt for aluminium rivets or stainless steel.

Flotation

Another benefit of using wood over aluminium for your deck is the flotation factor. Wood has a lower specific gravity than aluminium, which means it will float more easily. So, while aluminium may be stronger and more durable, wood is a better choice if you are concerned about the weight and flotation of your boat.

Maintenance

Finally, keep in mind that wooden decks will require regular maintenance. Even with the best waterproofing, wood can still rot over time, especially in a marine environment. Be prepared to replace or treat your wooden deck every few years to keep it in good condition.

Protecting the wood with fibreglass and resin

Firstly, it is important to prepare the wood surface thoroughly. Start by removing any paint or foreign material from the wood. Ensure the wood is clean and dry. Next, use a sanding board to sand the surface with the grain, which will help prevent small hollows. Remove dust by vacuuming and wiping the surface with paper towels dampened with lacquer thinner. This step will help reveal any scratches or marks and give you an idea of how the surface will look when coated.

Once the surface is prepared, it's time to apply a resin penetration coat. This step will help the fibreglass and resin bond more effectively to the wood. Thin the resin with a solvent before applying it to the wood. For epoxy resin, mix it with a hardener and thin it with an epoxy solvent. If using polyester or vinylester resin, catalyse and thin it with acetone. Be sure to follow safety guidelines and never mix polyester and epoxy resins together. Brush or roll the thinned resin onto the wood, covering as many surfaces as possible. Allow the resin to cure completely before lightly sanding the surface again.

Now, you are ready to apply the fibreglass. Choose a lightweight fiberglass cloth, such as 4 oz or 6 oz per square yard, as this will provide maximum clarity and allow the wood grain to show through. Cut the fibreglass to size, ensuring it covers all the areas of the wood you want to protect.

Finally, it's time to apply the resin. Mix the resin with a hardener, following the manufacturer's instructions. Use a paintbrush to apply the resin to the fibreglass, wetting it out thoroughly. Be sure to work in a well-ventilated area and follow all safety guidelines when working with resins. Allow the resin to cure completely before applying any additional coats or build-up layers, if needed.

By following these steps, you will effectively protect the wood decking of your aluminium boat with fibreglass and resin, ensuring a long-lasting and durable finish.

Using treated lumber on an aluminium boat

Most types of treated wood contain copper, which is the main issue. When copper comes into contact with softer metals like aluminium, it causes corrosion. While this may not be immediately apparent, water causes the copper to leak out of the wood, which then eats holes in your aluminium boat.

Before holes appear, you will likely notice pitting, indentations, and other signs of corrosion. These will worsen over time, and you may need to totally replace the wood and repair the boat if it is even salvageable.

If you already have treated wood in your boat, or you are committed to using it, you will need to create a barrier between the treated wood and the aluminium. Paint may not be enough, so consider using a product like plastic bunk slicks to cover the wood and prevent direct contact. You should also coat or cover any bolts used to secure the wood, as they can also corrode over time.

The best way to avoid this issue is to simply use untreated wood. You can seal regular exterior plywood yourself with a sealant that does not contain copper. Alternatively, you could use aluminium sheets, which are lightweight and won't rot.

Using pressure-treated wood on aluminium boats

Pressure-treated wood is a common material used in boat decking. However, when it comes to aluminium boats, there are some important considerations and precautions to be aware of.

The chemicals used in pressure-treated wood can leech out and cause pitting and corrosion in aluminium. This is due to the dissimilar metals reacting when exposed to water, especially saltwater. Even without direct contact, if the treated wood gets wet and the chemicals leech out, they can damage the aluminium. Additionally, the swelling of the wood due to water absorption can put stress on the aluminium and cause mechanical damage.

If you decide to use pressure-treated wood on your aluminium boat, it is crucial to take the following steps:

• Avoid direct contact between the pressure-treated wood and the aluminium. Use a barrier or shield made of plastic, rubber, or thin sheets of rubberised coating.
• Seal the wood thoroughly with a suitable coating. Options include epoxy resin, polyurethane varnish, fibreglass resin, or marine paint. Apply multiple coats, especially along cut edges, to prevent water absorption and swelling.
• Avoid using galvanised fasteners as they can also cause corrosion in the aluminium.
• Regularly inspect and maintain the wood and coatings to ensure their integrity.

It is worth noting that some boat owners and experts consider it best to avoid pressure-treated wood altogether and opt for untreated wood or alternative materials such as epoxy, fibreglass, or composite decking. These options may be more expensive initially but can save you from potential corrosion issues and the need for frequent replacements.

Using epoxy to seal wood for boat decks

Epoxy is a great way to seal wood for boat decks, especially when combined with fibreglass. This method can be used to seal wood for aluminium boats, as well as wooden boats.

Firstly, it's important to note that the wood must be bare and unfinished for the epoxy to penetrate and seal effectively. The epoxy will not penetrate and level well if applied over some stains, so be sure to test a small area first.

To begin, you'll need to carefully resin every wooden part after assembly. You can use epoxy resin on its own, or thin it with acetone or denatured alcohol to improve penetration into the wood. Apply the thinned resin to the wood, allowing it to soak in. Once the wood stops soaking up the thinned resin, you can apply more without thinning to build up a protective layer. Three coats applied wet-on-tacky will avoid the need for sanding between coats.

After the epoxy has cured, you can add a thin layer of fibreglass to the top surface of the wood. This will further protect the wood and improve its durability. Once the fibreglass has been applied, you can add a second thin coat of resin to seal in the fibreglass.

If you're planning on painting or varnishing the wood, you'll need to wait for the epoxy to fully cure, then wash with water, sand smooth, and clean the surface before applying your chosen topcoat.

Frequently asked questions