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How to Repair an Aluminum Boat? – Easy Care Guide

Written by J. Harvey / Fact checked by S. Numbers

how to repair aluminum boat

An aluminum boat is more advantageous than vessels made of wood and fiberglass because they are lightweight, maneuverable, and fast. Nevertheless, aluminum boát have their weaknesses.

Aluminum is prone to damages from hard grounding or collision. You may have to deal with cracks and leaks that can interrupt your sailing. That’s why it’s crucial to learn how to repair aluminum boat.

More than just buying an aluminum boat repair kit, you will need epoxy and glue to patch and fill in voids. For more detailed information, continue reading. By the end, you should be able to mend your aluminum boat if it’s needed.

Possible Issues That Need To Be Repaired On An Aluminum Boat


Before proceeding to the actual repairs, you have to take your aluminum boat out of the water. Then, you can move it to a port in a covered garage. Arrange three sawhorses in a triangle on a flat surface. It’s where you put your boat.

You can get a hand to lift the boat and balance the sides. Get some rags and acetone to clean the damaged section. Keep in mind that you aim to remove algae, water, and mud stains entirely.

It’s best to wear protective gear when cleaning, such as a mask and pair of gloves. To work comfortably and efficiently, you need to put your boat in a position that exposes the hole or crack.

1. Dealing with Dents

The impact of a collision can cause an inward dent to the hull. To start, ask someone to hold the anvil while you wield a hammer. This dent or a hill-like form should be pounded by a hammer to return to a flat state.

The person who acts as your assistant should utilize one hand anvil to give a backstop. The hull flattens by tapping and straightening. The aluminum surface must stretch to regain its original shape.

2. The Size of Holes or Cracks

Some dents come with holes or cracks, and these mean more work. The very first step is determining the size of a specific gap or crack. Aluminum scrap strips can back you up with this procedure.

You’ll need to dab epoxy for aluminum boats on the thin aluminum strips, and glue them on the boat’s base. This is how to fulfill your intention of covering the cracks. It will create a crib for some materials like a brazen rod to occupy.

3. Patching Up Holes

Aside from a hammer, you can utilize a bucking dolly or auto-body to get rid of dents. I recommend flattening the torn edges as well. In this way, cracking on the end of every tear will be prevented.

When engaging in aluminum boat patching, you must establish a toned bonding surface. Hence, you have to soften the edges of the aluminum by using 120-grit sandpaper.

Also, remove the paint inside and outside with the help of a coarse bristle disc. The final step for softening the edges is abrading with 80-grit sandpaper. At this point, you’re ready to start with the repairs.

You can make patches from a glass fabric. Cut them based on the size of the hole. A single patch is sufficient for the exterior side, and you need three for the interior. They should be in diminishing sizes.

Give a two-inch allowance for each patch, so there’s extra material to overlap and bond around the hole. Then, brush aluminum boat repair epoxy on both surfaces.

Regarding this step, you can use good marine epoxy like Amazing Waterproof Epoxy Sealer, TotalBoat TotalFair Marine Epoxy, and Travaco Marine-Tex Waterproof Epoxy Sealer. You may also want to buy silica for filling tiny holes or cutaways around the area that’s under repair.

Soak the patches that you’ve cut with the chosen epoxy. Lay them out while doing this step. Then, start placing the patch over the hole on the exterior side and add the epoxy.

Continue by placing the three patches for the inside part. Adjust their position to be in the center and over the hole. You must use a squeegee to block the air. When all of the patches are on the center of the hole, you know it’s time to put the squeegee to work again ensuring that the air doesn’t get inside.

After you have arranged everything correctly, you should put it in the curing process overnight. You should remove any roughness on the edges of the patches the next day. Ground them first and apply marine filler like 3M Marine Adhesive Sealant Fast Cure and Hypoxy Aluminum Putty.

When the mixture is fully cured, you can further conceal the patches using camouflage paint or any aluminum boat paint that you like.

Tools For Repairing Cracks


1. Grinding Cone and Drill Motor

To grind a V-shaped channel on the crack, the grinding cone and drill motor are the necessary aluminum boat repair products or tools. When there’s a puncture on your boat, you have to bevel the inner part of the hole puncture using a cone bit.

You have to continuously grind until you capture enough of the surface area for the brazen weld. Keep in mind that the brazen weld will stick to that place. I recommend sanding all the cracked areas with 220-grit sandpaper. Also, overlap the areas from every side.

2. Propane Torch

A cracked area needs a propane torch for the heat. Then, you can scrape it with a wire brush. If there’s an uneven surface, do crosshatch strokes. The heat coming from the torch should be consistent when fixing the brazen rod on each side of the crack.

Some use a tig welder to bind aluminum sheets and bring out great results. Moreover, heat is important as it can melt the brass plate, which will flow into the crack or hole.

Once the brass melts, it can suitably fill the gap and enclose the damaged area. Let it cool down before you get rid of residue. A wire brush can help you scrape those unwanted bits.

How to Repair Aluminum Boat by Filling Screw Holes on the Surface

  • Cut an aluminum strip that is an inch bigger than the hole by utilizing a tin snip. Use a steel clamp when you place it on the opening.
  • To weld the aluminum, a propane torch can help.
  • Sanding is the next step, with coarse-grit first then fine-grit to finalize.

Fixing Corrosion on Aluminum Boats

You can do this by making a solution consisting of 10 percent sulfuric acid and chromic acid. These kinds of acids are excellent inhibitors of aluminum alloy. Applying using a brush or swab, making sure that you dampen the corroded area before scrubbing.

When the corrosion has resulted in pitting, you can follow the repair methods mentioned above.

Final Words

In spite of how much you take care of your boat, mishaps and accidents are inevitable. Just like how aluminum boats don’t have immunity from damages. Even if it happens, there are different ways on how to repair aluminum boat.

Collect the necessary materials mentioned above, and just follow the steps. Make sure that you mindfully execute the procedures to achieve a refined result.

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