Replacing Rivets: Grumman Aluminum Boat Maintenance Guide

Owning an aluminium boat can be a lot of fun, but it also comes with maintenance work. One common issue with aluminium boats is rivet failure, which can cause leaks. This is a problem that many boat owners face, and there are various methods to fix it. Some people choose to replace the rivets with bolts, while others opt for welding or special adhesives. However, the most common solution is to simply replace the old rivets with new ones. This process requires some specialised tools and a good understanding of the procedure, but it is a relatively straightforward task for those with the right skills and equipment.

How to identify and source rivets for your Grumman aluminium boat

To identify the rivets you need for your Grumman aluminium boat, you'll need to know the model and age of your boat. This will help you source the correct rivets for your boat. For example, a 1977 Grumman 3.8 12 ft aluminium boat will have different rivets from a newer model.

Once you have this information, you can search for rivets that match the size and type of your boat's original rivets. You can find rivets at marine supply stores, hardware stores, or online. When searching for rivets, you may come across terms like "solid rivets", "blind rivets", "pop rivets", "brazier head rivets", and "mandrel". Solid rivets are the most common type of rivets used in boat manufacturing, while blind rivets (also known as pop rivets) are easier to install and can be found in aluminium or steel. The "mandrel" is the long pin in the centre of the rivet, and the "brazier head" is a type of rounded or dome-shaped head.

When purchasing rivets, you'll want to make sure you have the correct size and length. Rivets are measured by their diameter and length, so you'll need to measure the original rivets in your boat to ensure you get the right fit. For example, you may need rivets that are 3/16" in diameter and 3/8" in length.

In addition to rivets, you'll also need the right tools to install them. If you're using solid rivets, you'll need a rivet gun, a bucking bar or anvil, and possibly a drill. If you're using a pop rivet gun, you won't need a drill, but you may still want to invest in a bucking bar to help with installation.

When it comes to actually installing the rivets, there are a few techniques you can use. One method is to centre punch the rivet to create a straight hole, drill out the old rivet, and then use a vice grip to bend the lip of the boat up or down to get the rivet in place. Another method is to knock the head of the rivet loose, drill it out, and then use a rivet gun to install the new one.

Remember to always follow safety precautions when working with boats and power tools, and if you're unsure about any part of the process, it's best to consult a professional boat repair service.

Tools and equipment needed to replace rivets

To replace rivets in a Grumman aluminium boat, you will need a variety of tools and equipment. The specific items will depend on the type of rivets you are installing and the method you are using to replace them. Here is a list of tools and equipment that you may need:

• Drill
• Drill bits
• Rivet gun
• Rivets (solid, blind, or closed-end)
• Pop rivets
• Stainless steel bolts and nuts
• Waterproof sealant (e.g. 3M 5200, marine epoxy, or marine-grade caulk)
• Emery cloth
• Hammer
• Bucking bar or heavy padlock
• Air hammer
• Air tools
• Ball-peen hammers
• Centre punch
• Chisel
• Variable speed drill with split point bit
• Rivet set
• Brazier head rivet
• Closed-end blind rivets
• Monel rivets

Before beginning the rivet replacement process, it is important to assess the condition of the boat and identify any leaks or damaged rivets. This will help you determine the extent of the repairs needed and the specific tools and equipment required.

Additionally, it is recommended to have basic personal protective equipment, such as gloves and eye protection, when working on boat repairs.

How to remove old rivets

Removing old rivets from an aluminium boat can be a challenging task, but with the right tools and techniques, it can be accomplished. Here is a step-by-step guide on how to remove old rivets:

Assess the Rivets:

Before beginning the removal process, it is important to identify the type of rivets used in your Grumman aluminium boat. The most common types are solid rivets and blind/pop rivets. Solid rivets are typically used in aluminium boats and are installed with a special tool that buckles the tail end of the rivet, while blind/pop rivets are commonly used for smaller repairs and can be installed with a hand tool that pulls a nail through the hollow rivet.

Gather the Necessary Tools:

The tools you will need depend on the type of rivets you have. For solid rivets, you will need a drill, drill bits, centre punch, sharp chisel, and a hammer. For blind/pop rivets, you may only need a drill and drill bits of the same size as the rivet shaft. It is recommended to use cobalt bits when drilling aluminium, as they provide a cleaner cut and reduce the risk of bit breakage. Additionally, having a grinder and a small punch can be useful for removing stubborn rivets.

Prepare the Work Area:

Before starting the removal process, make sure you have adequate lighting and a stable work surface. If possible, place the boat on a stand or blocks to provide better access to the rivets. Cover nearby areas with a tarp or drop cloth to protect them from debris and metal shavings.

Drill Out the Rivets:

For solid rivets, begin by centre-punching the head of the rivet to create a small indentation that will help guide your drill bit. Select a drill bit that matches the size of the rivet shaft and slowly drill into the centre of the rivet head. Go slow and maintain a straight, upright drilling position to avoid bit breakage and minimise the risk of tempering the rivet, which can make it harder to drill. Once you have drilled through the head, use a sharp chisel and a hammer to knock off the head, exposing the tail end of the rivet. Drill out the tail end, and the rivet should come out easily.

For blind/pop rivets, simply drill through the visible side of the rivet with a drill bit that matches the size of the rivet shaft. The blind side of the rivet should fall out, leaving the shaft and head exposed for easy removal.

Remove Remaining Rivets:

If you encounter stubborn rivets that are difficult to drill out, you can use a grinder to remove the head and punch out the remainder of the rivet with a small drift or punch. Alternatively, you can use a blow torch to heat and blow out the rivets, but this method may not be feasible for everyone.

Clean and Prepare the Holes:

Once all the old rivets have been removed, use a wire brush to clean the holes and the surrounding aluminium surface, removing any debris, corrosion, or residue. This step is crucial for ensuring a strong bond when installing the new rivets.

Remember to take your time, work patiently, and always prioritise your safety when working with power tools and sharp objects. With these steps, you should now have a good understanding of how to remove old rivets from your Grumman aluminium boat.

How to install new rivets

To install new rivets in a Grumman aluminum boat, you will need to follow these steps:

First, identify the leaking rivets by filling the boat with water while it is on the trailer. Pop the heads off the leaking rivets with a knife and punch out the remainder of the rivet without distorting the hole. Clean the area with a wire brush and apply a coat of sealant or primer to prevent corrosion.

Next, insert a new rivet from the outside of the boat. Use a concave tool that fits the rivet head and hit the rivet a few times, signalling to your helper that they should push back with a piece of steel. Repeat this process until the rivet head is caulked and properly formed, and the inside is upset correctly. Drill out any remaining loose rivets with a nominal-sized drill bit to avoid distorting the hole.

When setting the rivet, ensure the smooth side faces the water. You can also use a pop-rivet gun to install closed-end, blind rivets. Make sure to wear ear protection as riveting can be loud.

Finally, apply a final coat of sealant to the rivets to ensure a watertight seal.

It is important to note that riveting is a two-person job and can be loud, so proper safety precautions should be taken.

How to seal rivets to prevent leaks

To seal rivets on your Grumman aluminum boat and prevent leaks, you must first identify the source of the leaks. There are several methods to do this, including:

• Filling the boat with water and marking the leaking rivets.
• Using a suction cup-type dent puller to identify leaking rivets.
• Beaching your boat and gradually sliding it into the water, marking the leaking rivets as you move along.

Once the leaking rivets have been identified, you can begin the process of sealing them to prevent future leaks. Here are the steps you can follow:

• Clean and prepare the surface for bonding: Use a wire brush in a circular motion to abrade the surface and clean out any debris or old sealant around the rivets.
• Gather your materials: You will need a handheld propane torch or a heat gun, an epoxy syringe, paper towels, and an epoxy product such as G/flex 650 Epoxy, West System G/Flex 650-K Aluminum Boat Repair Kit, TotalBoat FlexEpox, or TotalBoat Aluminum Boat Leak Sealer.
• Mix the epoxy: Following the manufacturer's instructions, mix the resin and hardener components of the epoxy together and fill the syringe.
• Heat the repair area: Use a propane torch or a heat gun to heat the repair area to a temperature of 180–220°F. This will help dry out the area and thin out the epoxy, allowing it to flow more easily into the seams and rivets.
• Fill the rivets: With the aluminum still warm, use the heat gun in one hand to direct the forced air to the repair area, while applying the epoxy from the syringe with the other hand.
• Apply heat until the epoxy gels: Continue applying heat until the epoxy has gelled and no longer moves with the forced air. Then, you can let the epoxy cure at ambient temperature or use the heat gun on a lower setting to speed up the curing process.
• Test the repair: Once the epoxy is cured, you can take your boat out on the water to test the repair.

It is important to note that while epoxy is a common and effective method for sealing rivets and repairing leaks, it may not always be a permanent solution. In some cases, you may need to consult a professional or consider other repair methods, such as welding or replacing the rivets.

Frequently asked questions