Refurbishing A 14-Foot Aluminum Boat: Adding A Wooden Floor

Adding a floor to a 14-foot aluminium boat is a popular topic of discussion among boat enthusiasts. Many opt for a wooden floor, with some choosing to use plywood, and others suggesting aluminium or sheet metal. The main considerations are weight, ease of installation and removal, and the prevention of corrosion.

Using plywood for flooring

Plywood is a popular material for flooring in aluminium boats. It is important to note that not all plywood is created equal, and some types of plywood should be avoided when flooring an aluminium boat.

Firstly, pressure-treated plywood should be avoided. This type of plywood will corrode your aluminium boat very quickly. Marine-grade plywood is a superior product but comes at a higher cost. Exterior-grade plywood is a good option and can be sealed with epoxy resin. One source suggests that the glue used in marine-grade and exterior-grade plywood is the same, and the main difference is that marine-grade plywood does not have voids. Another source, however, states that the glue used in both types of plywood is water-resistant, not waterproof, and that only marine-grade plywood uses waterproof glue.

Marine-grade plywood is made up of layers with no voids, whereas exterior-grade plywood may have voids and unplugged knot holes in the inner plies. The large difference in price between the two is due to the high quality of all the plies in marine-grade plywood. If you plan on keeping your boat forever, it may be worth investing in marine-grade plywood. However, if you are on a tight budget or only plan on keeping the boat for a few years, exterior-grade plywood should be more than sufficient.

When it comes to the thickness of the plywood, 1/2" exterior-grade plywood should be enough. Thicker plywood can be overkill and heavy. However, if you want to use plywood, it is important to make sure that the thickness is enough to run across the ribs of your boat.

Before installing the plywood, it is important to coat both sides and the edges with a penetrating epoxy to protect the wood from water damage. There are specific products available for this purpose, such as Penetrating Epoxy Sealer. After the epoxy has cured, you can paint over it with a topside boat paint if desired.

When it comes to attaching the plywood to your boat, riveting is one option. However, it is important to use rivets that are compatible with the aluminium hull to prevent galvanisation. Another option is to use stainless steel screws. If you want the floor to be removable, you can use rivnuts to attach the plywood.

Finally, when it comes to flooring material to put on top of the plywood, marine-grade carpet or vinyl are popular options. Marine carpet can be attached with canvas snaps, making it removable for cleaning and drying. Vinyl is also a good option and can be purchased from specialist marine suppliers or more general retailers.

Ensuring stability and portability

When installing a wooden floor in your aluminum boat, stability and portability are key considerations. Here are some tips to ensure your floor is both stable and portable:

Ensure Stability:

• Use the right materials: Avoid using pressure-treated wood as the chemicals used to treat the wood can corrode aluminum, eating holes in your boat over time. Instead, opt for marine-grade plywood and seal it with an oil-based paint or marine spar varnish to protect it from water damage.
• Create a sturdy frame: Construct a frame using lightweight materials such as 2x2s or 1x4s ripped to 1-1/2" square. This will provide structural integrity and help distribute weight more evenly, reducing the boat's lean when people move around.
• Maintain center of gravity: Be cautious about raising the floor too high, as this can alter the center of gravity and make the boat more prone to tipping.
• Ensure a secure fit: When installing the wooden floor, make sure it fits snugly into the boat. Use rivets or screws to attach the floor to the boat's hull and support structures.
• Consider flotation: Adding flotation devices or pour-foam underneath the floor can provide additional stability and ensure the boat rides flatter in the water.

Ensure Portability:

• Avoid permanent attachments: If you want the floor to be removable, avoid using screws or rivets that permanently attach the floor to the boat's structure.
• Use lightweight materials: Opt for lightweight plywood and framing materials to reduce the overall weight of the floor, making it easier to install and remove.
• Design for portability: Consider designing the floor in sections or modules that can be easily assembled and disassembled, making it more portable and manageable for one person to handle.
• Add handles or grips: Attach handles or grips to the floor to make it easier to lift and maneuver, especially if you plan to remove it frequently.

Remember, stability and portability are about finding the right balance. A sturdy and well-fitted floor will enhance the stability of your boat, while careful material selection and design choices will ensure it remains portable and easy to remove when needed.

Choosing the right materials

When it comes to choosing the right materials for installing a wooden floor in your 14-foot aluminum boat, there are several key considerations to keep in mind. Here's a detailed guide to help you make informed decisions:

Plywood:

The type of plywood you choose is crucial. Opt for marine-grade plywood, which is designed to withstand the harsh conditions of a marine environment. This type of plywood is constructed with water-resistant glues and is less likely to warp or rot over time. While it may be tempting to save costs by using standard plywood, it won't hold up as well and could lead to issues down the line.

Flooring Thickness:

The thickness of the plywood flooring is an important factor. While thicker plywood may seem like it would provide more durability, it also adds significant weight to your boat. A happy medium is to go for 1/2-inch-thick marine plywood. This provides a good balance between strength and weight, ensuring your boat remains stable and manoeuvrable.

Support Structures:

To ensure your wooden floor is sturdy and secure, you'll need to install support structures underneath. These can be made from wood or aluminium. If using wood, consider ripping 2x4s to 1-1/2-inch squares to reduce weight while still providing ample support. Alternatively, aluminium angle brackets or strips can be used, but they tend to be more expensive. Ensure the supports are fastened securely to the boat's ribs or stringers.

Fasteners:

Choosing the right fasteners is essential to securely attach your wooden floor without damaging your boat. Avoid using screws, as they can come loose, strip, or rattle over time. Pop rivets, especially aluminium ones, are a popular choice as they provide a strong hold and are less likely to corrode due to dissimilar metals. If you want an easily removable floor, consider using heavy-duty Velcro or nutserts, which can also help reduce galvanic corrosion.

Flooring Finish:

To protect your wooden floor and ensure it lasts for years, a finish is necessary. You can paint it with non-skid paint or marine spar varnish to provide traction and seal the wood. Alternatively, consider covering the plywood with marine carpet, which adds comfort and a more refined look to your boat. Just ensure the carpet is secured properly to avoid any tripping hazards.

Centre of Gravity:

When installing a wooden floor, be mindful of your boat's centre of gravity. Adding too much weight or raising the floor too high can make your boat tippy and unstable. Always consider the weight distribution and ensure the floor is level. This is crucial for the safety and performance of your boat.

Remember, the key to a successful wooden floor installation is to use high-quality, marine-grade materials, minimise weight where possible, and ensure secure fastening methods. Taking the time to choose the right materials will result in a more enjoyable and safer boating experience.

Fixing the floor in place

Planning and Preparation:

Before starting the installation, it is crucial to have a clear plan and gather the necessary materials. Measure the dimensions of the boat's interior and decide on the type of wood you will be using, such as plywood. Consider the weight of the flooring material, opting for lighter options like aluminium sheet metal or marine-grade plywood to avoid adding excessive weight to the boat. Additionally, ensure you have the required tools and safety equipment, including gloves and eye protection.

Support Structures:

To ensure a stable floor, create a sturdy framework to support the plywood. This can be done by cutting stringers or support pieces from wood, such as 1x4s or 2x3s, that match the contour of the boat's bottom. These stringers should rest on the reinforcing ribs of the boat, providing a solid base for the floor. Ensure the stringers are level and securely fastened to the ribs using appropriate fasteners or adhesives.

Securing the Plywood:

When installing the plywood floor, it is essential to avoid screwing or drilling into the hull of the boat. Instead, opt for other fastening methods. One option is to cut the plywood sheets to fit snugly between the bench seats and fasten them to the upright braces of the seats. Another method is to use rivets compatible with aluminium to avoid galvanic reactions. Ensure the rivets are long enough to provide adequate holding power without compromising the hull's integrity.

Centre of Gravity and Safety:

Be cautious about the height of the floor installation to avoid altering the boat's centre of gravity. A floor that is too high can make the boat unstable and prone to tipping. Additionally, consider adding flotation devices or materials underneath the floor, such as styrofoam, to enhance buoyancy and safety.

Finishing Touches:

Once the floor is securely in place, you can add finishing touches like marine spar varnish or paint to protect the wood and enhance its appearance. Ensure any coatings are compatible with aluminium to prevent corrosion. You can also add marine carpeting to the floor for added comfort and traction.

Remember to take your time, work carefully, and always put safety first when working with power tools and around watercraft.

Avoiding corrosion

When installing a wooden floor in an aluminium boat, it is important to consider the risk of corrosion. Corrosion can occur when dissimilar metals come into contact with each other, leading to a chemical reaction that can damage the boat's hull. Here are some tips to help avoid corrosion when installing a wooden floor in a 14-foot aluminium boat:

• Do not use treated wood: This is because treated wood can contain copper, which can leach into the bilge and cause galvanic corrosion. Untreated plywood or aluminium sheet metal are better alternatives.
• Avoid using fasteners that react with aluminium: When attaching the wooden floor to the aluminium boat, ensure that any fasteners, such as rivets, are compatible with aluminium to prevent galvanic corrosion.
• Use a buffer: When cleaning or restoring an aluminium boat, it is recommended to use a linear buffer with an Alumabuff Pad Kit to remove corrosion and restore the surface. This method is more effective and less labour-intensive than doing it by hand.
• Apply protective coatings: After cleaning and restoring the aluminium surface, apply protective coatings such as Alumetron and VS721 to prevent corrosion and extend the life of the boat. These coatings can last for several years and provide additional benefits like improved performance and reduced fuel consumption.
• Avoid welding corroded aluminium: Welding corroded aluminium can be risky as the heat from welding can cause steam explosions in corroded areas, leading to further damage. It is essential to thoroughly clean and prepare the aluminium surface before attempting any repairs or modifications.
• Use compatible sealants: When filling holes or making repairs, use sealants that are specifically designed for use with aluminium, such as 3M 5200 Marine Sealant. Avoid using epoxy or other incompatible sealants, as they may not adhere properly and could introduce new problems.
• Regular maintenance: To prevent corrosion and maintain the condition of your aluminium boat, it is important to regularly wash it with fresh water after each use and keep it on a trailer to minimise contact with water.

Frequently asked questions