Protecting Aluminum Boat Gunwales: Tips For Longevity

Aluminum gunwales are an essential component of a boat's structure, providing stability and protection. They are the upper edges of a boat's sides, running horizontally along the hull. Given their importance, it is crucial to know how to protect them from damage and deterioration. This is especially true for aluminum boats, which are susceptible to scuffs and dents. Proper maintenance and care can help prevent damage and corrosion, ensuring the gunwales remain in top condition. This includes regular cleaning and polishing, as well as taking preventive measures such as applying protective coatings and avoiding abrasive materials. For those looking to repair or replace damaged aluminum gunwales, there are several options, including welding, bending, and filling techniques.

Repairing aluminium gunwales with paint or bondo

To repair aluminium gunwales, you can use paint or Bondo. If you're looking for a quick fix, paint can be a simple solution. However, if you want a smoother finish and more durable solution, Bondo, an epoxy putty or filler, might be a better option. Here's a step-by-step guide on how to repair aluminium gunwales with paint or Bondo:

Repairing Aluminium Gunwales with Paint:

• Clean the surface: Before starting the repair, make sure the gunwales are clean and free of any dirt, grease, or debris. You can use a mild detergent or boat soap and water to clean the area.
• Sand the damaged area: Use fine-grit sandpaper to sand the scuffs, scratches, or damaged areas. Sand until the surface is smooth and even, creating a suitable surface for the paint to adhere to. Wipe away any dust with a tack cloth or a damp cloth.
• Apply primer (optional): If the aluminium is bare, it's recommended to apply a primer designed for use on metal surfaces. This will help the paint adhere better and provide a more durable finish.
• Paint the gunwales: Choose a paint that is suitable for aluminium surfaces and matches the colour of your boat. You can use a small brush or a spray paint designed for metal surfaces. Apply thin, even coats, allowing adequate drying time between coats as per the paint manufacturer's instructions.
• Sand and recoat (optional): Once the paint has dried, you may need to lightly sand the surface again with a very fine grit sandpaper to smooth out any imperfections. Wipe away the dust and apply additional coats of paint as needed until you achieve the desired finish.

Repairing Aluminium Gunwales with Bondo:

• Clean and prepare the surface: As with painting, make sure the area is clean and free of any contaminants. Bondo will adhere better to a rough surface, so use a coarse grit sandpaper to scuff the area and create a suitable surface for the Bondo to stick to.
• Mix the Bondo: Bondo usually comes in two parts: a resin and a hardener. Follow the manufacturer's instructions for mixing the correct ratio of resin and hardener. Mix only a small amount at a time, as it will start to harden quickly.
• Apply the Bondo: Using a putty knife or spreader, apply the Bondo to the damaged areas of the gunwales. Try to create a smooth, even surface that matches the shape of the gunwales.
• Let it cure: Bondo typically takes several hours to fully cure. Refer to the manufacturer's instructions for the exact curing time.
• Sand and paint: Once the Bondo has cured, use fine-grit sandpaper to sand the repaired areas until smooth. Wipe away any dust, then prime and paint the repaired areas to match the colour of your boat. Follow the same steps as mentioned in the painting section above.

Remember to wear protective gear, such as gloves and a respirator, when working with Bondo or paint. Additionally, always work in a well-ventilated area to ensure proper airflow during the repair process.

Using composite materials for gunwale repair

Gunwales, also known as "gunnels" or "rails", are the part of a boat that runs along the top edge of the hull. They are often made of wood, aluminium, or composite materials like Kevlar or carbon. While wood gunwales provide a classic and traditional look, they require regular maintenance to prevent rotting and need to be stored indoors during the off-season. On the other hand, aluminium gunwales are virtually maintenance-free and cost-effective, but they can heat up in the sun and get quite cold in low temperatures. Composite materials, such as those used in modern Azek decking, offer a durable and lightweight alternative for gunwale repair.

When repairing or replacing gunwales, it is important to consider the advantages and disadvantages of different materials. Composite materials, such as those used in modern decking, can provide a strong and durable solution. Here is a step-by-step guide to using composite materials for gunwale repair:

• Assess the damage: Inspect the gunwales for any cracks, splinters, or other damage. Take note of the extent and location of the damage, as this will influence the repair process.
• Prepare the work area: Gather all the necessary tools and materials, including safety gear such as gloves and eye protection. Make sure you have a clean and well-lit workspace to ensure a smooth repair process.
• Remove the old gunwales: Carefully remove the old gunwales, preserving any attached components such as seats, thwarts, and portage yokes. Clean the area by removing any dirt, debris, or leftover material. File down any rough spots to create a smooth surface for the new gunwales.
• Measure and cut the composite material: Measure the length of the gunwales needed, taking into account the specific dimensions of your boat. Using a table saw, cut the composite material to the desired width and length. Ensure precise measurements for a snug fit.
• Create a kerf: Using a table saw, cut a kerf (a thin slit) along one edge of the composite material. This kerf will act as a slot to fit over the edge of the hull, providing a secure attachment point.
• Attach the composite gunwales: Apply a suitable adhesive or caulk to the kerf and the edge of the hull. Fit the composite gunwales into place, ensuring a tight and secure fit. Use fasteners, such as aluminium rivets or SS bolts, to securely attach the gunwales to the hull.
• Finish and maintain: Once the composite gunwales are in place, finish them with a light sanding and a couple of coats of a protective sealant, such as WATCO. Remember to properly maintain your composite gunwales by following the manufacturer's recommendations for care and upkeep.

Removing and replacing gunwales

If you're looking to remove and replace the gunwales on your aluminium boat, there are a few things to keep in mind. First, it's important to choose the right materials. For a modern look, you can opt for a composite decking material like Azek. Alternatively, if you're going for a vintage restoration, exterior-grade plywood sealed with a product like The Old Timers Formula can be a good choice.

When it comes to fasteners, aluminium rivets are ideal, but if you need longer bolts, make sure to use SS bolts that are properly insulated from the tin. For glue, a product like Tite Bond III, which is waterproof, is recommended. It's also important to note that some silicones and curing agents can be corrosive to aluminium, so be sure to use the right products and prepare and prime the surface properly.

Now, let's talk about the process of removing and replacing gunwales. If you're working with a standard 14' v-hull rowboat, you might consider using thin-wall aluminium pipe. You can have a saw cut the pipe down lengthwise through one wall, then slip it over the bare edge of the aluminium. To hold it in place, you could create 'O' straps out of bendable aluminium and rivet them to the hull every 16" or closer.

If you're looking to replace aluminium gunwales with vinyl, it's important to note that there may be issues with matching the thickness. Old Town replacement vinyl is an option, but it's generally made for poly boats, and Royalex is thicker. Keep in mind that converting the decks is the most challenging part, while seats, yoke, and thwart are not a problem.

Protecting gunwales with a protective coating

Gunwales are an essential component of a boat's structure, providing stability and rigidity to the vessel. They are also crucial for the safety of passengers and crew members, offering a secure handhold when boarding or exiting the boat. Given their importance, it is vital to maintain and protect your boat's gunwales. One effective way to do this is by applying a protective coating.

• Preventing Corrosion: A marine-grade protective coating acts as a barrier against the elements, reducing the risk of corrosion. This is especially important for aluminum gunwales, as corrosion can weaken their structural integrity over time.
• Ease of Maintenance: Protective coatings can make your gunwales easier to maintain. They create a smooth surface that is simpler to clean and less likely to accumulate dirt and grime, which can contribute to corrosion if not addressed.
• Enhanced Appearance: Protective coatings can also enhance the appearance of your gunwales by providing a glossy finish. This not only improves the aesthetics of your boat but also makes it easier to spot any damage or corrosion that may occur over time.
• Impact Protection: By applying a protective coating, you can safeguard your gunwales from minor impacts and abrasions. This is particularly beneficial for aluminum gunwales, which, despite their durability, can be susceptible to scratches and dents.
• Extending Lifespan: Ultimately, a protective coating can extend the lifespan of your gunwales by safeguarding them from the elements, corrosion, and general wear and tear. This can save you money in the long run by reducing the need for frequent repairs or replacements.

When choosing a protective coating for your aluminum boat's gunwales, opt for a marine-grade product specifically designed for this purpose. These coatings are formulated to withstand harsh marine environments and offer long-lasting protection. Follow the manufacturer's instructions for proper application and reapplication to ensure optimal results.

Additionally, if your gunwales have existing damage, such as dents or scratches, it is advisable to repair them before applying the protective coating. This will ensure a smooth finish and maximize the protective benefits of the coating. You can explore repair options by consulting a professional boat repair service or referring to online boat maintenance resources.

Repairing damage with welding

If your aluminum boat's gunwale has sustained damage, welding can be an effective way to repair it. Here are some detailed instructions and considerations for repairing gunwale damage on an aluminum boat using welding:

Assess the Damage:

Before beginning any repair work, it's important to thoroughly inspect the gunwale and identify the extent of the damage. Take note of any bends, dents, or popped rivets. It's crucial to have a clear understanding of the damage before deciding on the best repair method.

Straightening the Gunwale:

If the gunwale is bent, you have a few options for straightening it. One approach is to use a large C-clamp to apply pressure and bend the gunwale back into place. This method may require some heat to help reform the metal. Another option is to remove the affected section of the gunwale, straighten it on a workbench, and then weld it back into place. This method may be more feasible if the damage is localized to a specific area.

Welding Techniques:

When welding aluminum, it's important to use the appropriate welding techniques and equipment. Aluminum welding often involves TIG welding or MIG welding. Make sure you are familiar with the welding process and have the necessary safety equipment, such as a welding helmet and gloves. If you are not confident in your welding skills, consider seeking the help of a professional welder or a local body shop.

Filling and Grinding:

After welding, you may need to fill in any gaps or imperfections with a compatible filler material. Once the filler has cured, grind the weld down to create a smooth surface. This process may require multiple passes with progressively finer grits of sandpaper to achieve a seamless finish.

Riveting:

In addition to welding, you may need to replace or add rivets to secure the gunwale to the hull. Choose rivets that are appropriate for the thickness of the aluminum and the location of the repair. Pop rivets can be convenient, but for structural integrity, solid rivets or SS bolts may be a better choice, especially in high-stress areas.

Finishing:

Finally, to protect your repair work and enhance the appearance of your boat, consider applying a coat of paint or varnish. Make sure to properly prepare and prime the surface before painting to ensure good adhesion and a long-lasting finish.

Remember, safety should always come first when working with power tools and welding equipment. Take the necessary precautions and wear appropriate protective gear throughout the repair process.

Frequently asked questions