How Ribs Strengthen Aluminum Boats And Improve Performance

Aluminum boats are known for their lightweight strength, durability, and fuel efficiency. The ribs of an aluminum boat are an essential structural component that provides support and stability. These ribs are often made of aluminum, contributing to the boat's overall lightweight construction. However, the ribs can be susceptible to damage, and cracks or breaks may occur over time, especially in older boats. In this case, repairing or replacing the ribs becomes necessary to ensure the structural integrity of the boat.

Repairing broken ribs

Step 1: Assess the Damage

Before beginning any repairs, it is important to thoroughly inspect the boat and identify all the broken ribs. Look for cracks, fractures, or any other signs of damage. It is crucial to determine the extent of the damage to plan the repair process effectively.

Step 2: Prepare the Work Area

Before starting any repair work, make sure you have a clean and well-lit workspace. If possible, move the boat to a dry area where you have easy access to all the necessary tools and equipment. Ensure you have all the required safety gear, such as gloves and eye protection, before proceeding.

Step 3: Clean and Prepare the Surface

To ensure a strong and durable repair, it is essential to clean and prepare the surface of the broken ribs and the surrounding area. Use a wire brush or sandpaper to remove any dirt, grease, or corrosion from the aluminum surface. This step is crucial to ensure that the new welds or repairs will adhere properly to the existing structure.

Step 4: Repair or Replace the Broken Ribs

There are several methods you can use to repair or replace broken ribs, depending on the severity of the damage:

• Welding: If the cracks are accessible, welding can be an effective way to repair them. Clean the area thoroughly and use a TIG welder to fill in the cracks with new aluminum material. Ensure you use the correct alloy and filler material for the best results.
• Riveting a Brace: Another approach is to rivet a metal brace over the broken rib. Cut a piece of aluminum to match the profile of the rib, ensuring it is thick enough to provide adequate support. Drill holes through the broken rib and the hull, and then bolt the brace in place using stainless steel bolts, washers, and nuts.
• Replacing the Ribs: If the damage is extensive, you may need to replace the broken ribs entirely. This can be done by ordering new ribs from a dealer or fabricating custom ribs to match the original profile. Drill out the rivets holding the old ribs in place and install the new ones, ensuring they are securely fastened.

Step 5: Reinforce the Repaired Area

To ensure the longevity of your repairs, it is a good idea to add additional reinforcement to the repaired area. Consider installing aluminum cross-members or stringers to provide extra support to the ribs and reduce flexing. These can be riveted or bolted in place, connecting to the ribs and the deck of the boat.

Step 6: Final Checks and Maintenance

Once the repairs are complete, thoroughly inspect the boat to ensure that all rivets are tight and there are no remaining leaks. Apply a marine-grade sealant or epoxy to all seams and rivets to guard against future leaks. Regular maintenance and inspections will help ensure the long-term durability of your aluminum boat.

Remember that safety should always be a top priority when working on your boat. If you are unsure about any aspect of the repair process, don't hesitate to consult a professional or seek advice from experienced boat enthusiasts or forums.

Aluminium RIBs vs fibreglass RIBs

Aluminium RIBs are the ultimate in lightweight strength, durability, seaworthiness and fuel efficiency. They are usually cheaper and lighter in weight, which makes them easier to launch and beneficial when it comes to fitting specific weight limits. However, aluminium is susceptible to damage. While aluminium hulls will dent rather than crack or break upon impact, resulting in less costly repairs, a small scratch on the bottom hull can lead to faster corrosion. In saltwater environments, the protective oxide layer on the aluminium surface can also deteriorate, making the boat vulnerable to corrosion.

Fibreglass RIBs tend to have better seakeeping abilities and more stability due to their slightly bigger weight. A heavier RIB drifts slower and in a more predictable manner, which is beneficial for fishing. Modern technologies have also allowed fibreglass RIB boat manufacturers to remain lightweight where it is needed. Fibreglass boats are more complex in design, resulting in various elegant shapes that are easier to repair from small damages. When a small crack or hole appears, it usually requires only sanding, filling with fibreglass matt and gelcoat application, without the risk of any damage to the rest of the hull. Fibreglass also looks smoother and more attractive, and is quieter, making it more popular for recreational use.

Pros and cons of aluminium RIBs

RIBs, or rigid-hulled inflatable boats, with aluminium hulls are a popular choice for boat owners. They offer several advantages and disadvantages in terms of performance, durability, and maintenance. Here is a detailed look at the pros and cons of aluminium RIBs:

Pros of Aluminium RIBs:

• Aluminium hulls are lightweight, making the boats easier to transport and more fuel-efficient.
• They are highly durable and can withstand impacts without sustaining major damage.
• Aluminium hulls are ideal for handling rocky beaches and ledges, making them a popular choice in areas with challenging terrain.
• Aluminium RIBs are often equipped with high-quality materials, such as marine-grade aluminium and Hypalon or PVC tubes, ensuring a long-lasting and reliable vessel.

Cons of Aluminium RIBs:

• One of the main drawbacks of aluminium RIBs is the potential for corrosion, especially in saltwater environments.
• Aluminium hulls can be noisier than other materials, creating a less peaceful boating experience.
• The fabrication process for aluminium hulls is more challenging, making complex shapes harder to achieve.
• Repairs on aluminium hulls can be more complicated, especially after exposure to saltwater, which can contaminate the metal and affect welding.
• Aluminium hulls can be more expensive than other materials, such as fibreglass or GRP (glass-reinforced plastic).
• The metal can be very hot in warm climates and cold in cooler temperatures, impacting comfort.
• Paint or powder coating on aluminium hulls may bubble or peel over time, requiring maintenance.

Overall, aluminium RIBs offer a strong, lightweight, and durable option for boat owners, particularly those navigating challenging coastal environments. However, the potential for corrosion, higher costs, and maintenance considerations are important factors to keep in mind when deciding whether to opt for an aluminium hull.

Different types of aluminium ribs

Aluminium ribs, or rigid inflatable boats, are the ultimate in lightweight strength, durability, seaworthiness, and fuel efficiency. They are usually cheaper than their fiberglass counterparts and are lighter in weight, making them easier to launch.

Aluminium hulls will dent rather than crack or break upon impact, resulting in less costly repairs. However, aluminium is susceptible to corrosion, especially when exposed to saltwater. A small scratch on the bottom hull can lead to faster corrosion, and even without scratches, the protective oxide layer on the aluminium surface can deteriorate in saltwater, making the boat vulnerable to corrosion.

There are several types of aluminium RIBs available on the market, offering different features and specifications. Here is an overview of some of the different types:

• North Atlantic Inflatables: North Atlantic Inflatables offers two versions of aluminium RIBs: the Light Weight series (ALV) and the Classic Series (ALA). The Light Weight series features a single hull and a V-floor, while the Classic Series has a double hull with a welded-in flat floor deck. They also offer a Locker Series (L) with a welded-in bow locker for fuel tank storage. Their boats are made with high-tensile #5052 marine-grade aluminium and are powder-coated and baked to ensure a smooth and long-lasting finish.
• Alunautic Boats: Alunautic designs and produces aluminium RIBs in several lengths, with a V-shaped hull for high-speed performance. Their RIBs feature the EOS foam system for excellent buoyancy and anti-slide and self-bailing decks for added safety. The standard lengths offered are 7.00, 8.00, 9.00, 10.00, and 11.00 meters, with various extra options available.
• AB, Achilles, and Highfield: These brands offer aluminium RIBs with different features and specifications. AB is known for its bare aluminium hulls, while Achilles and Highfield offer powder-coated hulls. AB's deeper bow area makes it a good choice for rougher waters, while Achilles and Highfield's powder-coated hulls provide a smoother finish.

When choosing an aluminium RIB, it is important to consider factors such as intended use, durability, maintenance, and budget. Each brand and model has its own unique features, so it is essential to research and compare different options to find the one that best aligns with your specific needs and preferences.

How to install ribs

To install ribs on an aluminum boat, follow these steps:

First, assess the damage to the existing ribs. If they are cracked or broken, it is best to remove them and install new ones. This will ensure the structural integrity of your boat and prevent further issues down the line. Use a contour gauge to get an accurate profile of the existing ribs, which will be useful when creating the new ones.

Next, contact a decent aluminum fabrication shop. Provide them with the measurements and profile of the ribs that need to be replaced. They should be able to bend and cut new ribs from aluminum sheet metal using a brake, ensuring a precise fit.

Now, it's time to install the new ribs. Drill holes in the new ribs using the existing holes in the boat as a guide. Hold the new rib in place and drill from the outside of the hull, then bolt or rivet the new rib into place. For added strength, consider using closed-end blind rivets or stainless steel carriage bolts with oversized washers and a good sealant.

If you're reinforcing the structure by adding extra ribs, use aluminum channel, rectangular or square tubing, or angle pieces. Ensure these pieces are at least 1/8" thick and 1.5" in length. Drill holes where the new ribs meet the existing structure and use stainless steel carriage bolts and sealant for a secure fit.

Finally, consider adding a floor to your boat. Not only will this provide additional storage and tie-down options, but it will also act as a structural member, tying everything together and stiffening the entire boat. Don't forget to add foam underneath the floor panels for vibration and noise dampening, as well as added buoyancy.

Frequently asked questions