Choosing The Right Screws For Aluminum Boat Cleats

When installing cleats on an aluminum boat, it is important to consider the type of fastener used, the load it needs to bear, and the material of the fastener to prevent corrosion. While some people suggest using self-tapping metal screws, others advise against it as they can strip the aluminum and pull out over time. Instead, it is recommended to use machine screws with nylon lock nuts and fender washers to distribute the load and prevent corrosion. Access to the underside of the boat is ideal as it allows for the use of backing plates, which provide additional support. If access is limited, rivets or rivnuts can be used, but they may not provide the same level of strength as bolts. When choosing a fastener, it is crucial to select the appropriate size and material, such as stainless steel, to ensure the cleats are securely attached to the boat.

Stainless steel screws and washers

When installing boat cleats, it is important to use the appropriate size and type of screws. For aluminium boats, stainless steel self-tapping screws or machine screws are often recommended. Machine screws, also known as bolts, are typically used with washers and nuts to provide a stronger and more secure connection. It is also recommended to use a backing plate or backer board made of plywood to distribute the load and provide additional support.

When attaching cleats to an aluminium boat, it is crucial to consider the weight and stress that the cleats will need to withstand. Cleats can be subjected to high levels of stress during towing, anchoring, or in stormy conditions. As such, it is recommended to use through-bolting with backing plates and large fender washers, or to weld the cleats directly to the deck for maximum strength.

Additionally, the size of the cleats should be appropriate for the boat. For smaller boats, plastic cleats may be preferred as they are easier on the hands and ropes and are less likely to rust or pit. Larger boats may require bigger cleats to handle the increased weight and stress.

Machine screws and nuts

When installing new cleats on an aluminium boat, it is recommended to use machine screws, nuts, and washers. The size of the screws will depend on the size of the cleats. For example, small cleats may require a #10 screw, while larger cleats may need a 1/4" screw. It is also important to use a backer plate, which goes on the underside of the aluminium to provide extra support.

In addition to the hardware, it is recommended to use a marine-grade adhesive, such as 3M 5200 Marine Caulk, to create a watertight seal and prevent any adverse interactions between the stainless steel and aluminium. This will also help to ensure that the cleats are securely attached to the boat and can withstand the forces of docking, especially in rough weather conditions.

When installing machine screws and nuts, it is important to follow the correct procedure. First, drill pilot holes in the desired location. Then, insert the machine screws through the cleat and the aluminium boat. Secure the cleat in place by tightening the nuts onto the screws. Finally, apply a bead of marine caulk around the base of the cleat for added protection.

By following these steps and using the appropriate hardware, you can securely attach cleats to your aluminium boat, ensuring a safe and functional docking system.

Bolts

When installing bolts, it is important to first assess the load that the fastener will need to handle. Bolts should be used in conjunction with a strong backing plate made of aluminium or stainless steel, or heavy-duty fender washers, to spread the load. This is especially important when attaching items such as eyes, cleats, pedestals, handrails, windlasses, safety rail bases, and more.

When choosing bolts, opt for stainless steel as the material of choice for marine applications, excluding aluminium rivets. Avoid typical hardware store offerings of brass and plated steel.

When installing bolts, it is important to snug the threaded fasteners and then stop. Overtightening bolts can strip the threads or break the fastener. To prevent bolts from vibrating loose, coat the clean threads with a liquid thread-locking adhesive such as Loctite.

For cleat installation on an aluminium boat, stainless steel bolts with washers and nuts are recommended if you have access to the underside of the boat. If you do not have access, you can use rivnuts, which are aluminium-threaded rivets.

Self-tapping metal screws

When choosing self-tapping screws, it is important to consider the material. Stainless steel self-tapping screws are ideal for aluminium boats as they provide excellent corrosion resistance. Using a barrier like Tef-Gel or electrical tape between the screw and the aluminium can also help prevent galvanic corrosion due to direct contact between dissimilar metals.

The size of the self-tapping screws will depend on the size and weight of your cleats. For larger, heavier cleats, you may need longer screws with a higher thread count to ensure a secure fit. It is also recommended to use washers and backing plates to distribute the load and provide additional support.

When installing self-tapping screws, it is important to drill a pilot hole first. This ensures that the screw goes in straight and reduces the risk of damaging the material. Insert the screw slowly and stabilise it to prevent tilting. Do not overtighten the screws, as this can damage the aluminium or break the screws.

Self-tapping screws are advantageous for aluminium boats because they can withstand vibrations and movement, providing a reliable and long-lasting bond. They are also easy to remove and reuse, making them a practical and economical choice for boat modifications.

Blind rivets

When choosing blind rivets for an aluminium boat, it is important to consider the unique characteristics of rivets to ensure a strong and reliable connection. Here are some factors to consider when selecting blind rivets for your aluminium boat:

• Corrosion Resistance: Aluminium has good corrosion resistance, and riveting provides a secure connection that maintains the corrosion resistance of the aluminium, extending the life of the boat.
• Waterproof Performance: Choose sealed rivets or closed-end rivets that form a closed head, preventing moisture from penetrating the joints and reducing the risk of water leakage. This is especially important for applications that require use in wet or underwater environments.
• Strength and Reliability: Blind rivets have high tensile and shear strengths, providing a reliable connection. Closed-end rivets, in particular, have additional support and reinforcement due to their closed-head design, making them a good choice for marine applications where the fasteners need to withstand high stresses.
• High Sealing Performance: The closed head of sealed rivets provides an excellent seal, preventing the leakage of liquids or gases. This is crucial for maintaining the safety and longevity of aluminium boats.
• Installation Convenience: Rivets are easy and quick to install, making them a popular choice for connecting plates and parts during boat manufacturing.

When selecting blind rivets, it is also important to consider the specific application and requirements of your aluminium boat. For example, if you are repairing a patch below the waterline, you may need to take additional measures to prevent corrosion and ensure a strong seal.

Additionally, the quality of closed-end rivets can vary, so it is important to buy from a reputable manufacturer to ensure the safety of your boat. Consult with engineers or manufacturers to determine the appropriate material, head type, size, and other parameters for your specific application.

Overall, blind rivets are a great choice for connecting aluminium boat components due to their convenience, strength, and corrosion resistance. By considering the unique characteristics and selecting the appropriate type of blind rivet, you can ensure a safe and reliable connection for your aluminium boat.

Frequently asked questions