Patching Aluminum Boats: Quick Hole Fixes

Owning a boat is a dream for many, but it can quickly turn into a nightmare if you don't know how to maintain it. One of the most common issues boat owners face is dealing with holes in their vessels, which can lead to leaks and even sinking. While it may seem like a daunting task, patching a hole in an aluminum boat is possible, and there are several methods to choose from. Some people opt for welding or using a brazing rod (Alumiweld), while others prefer epoxy products, such as G/flex Epoxy, or quick fixes like JB Weld. Each method has its pros and cons, and the best approach depends on the size and location of the hole, as well as the boat owner's budget and skills.

Clean and shape the metal

To clean and shape the metal, you will need a hammer, an auto-body bucking dolly, a drill, 120-grit sandpaper, a coarse 3M® Roloc™ Bristle Disc, 80-grit sandpaper, and a coarse bristle disc.

First, use the hammer to get the hull back to its original shape by hammering out the torn aluminium. If you have access to one, you can also use an auto-body or bucking dolly. If there are any torn edges, cut them away to help the aluminium lie flat. To reduce the chance of cracking, drill stopper holes at the end of each tear.

Next, soften the edges of the aluminium with 120-grit sandpaper. Then, use a coarse bristle disc to remove paint from both the inside and outside of the boat, creating a sound bonding surface area. Finish by abrading the surface with 80-grit sandpaper.

Cut and prepare the patches

To cut and prepare the patches for an aluminium boat, you will need to cut a single piece of #743 280g/m2 Episize Glass Fabric for the outside of the hull and three pieces in diminishing sizes for the inside. The patches should be cut to allow for a two-inch overlap around the hole to give your materials space to bond. For example, if the hole is 6.5" by 8.5", your patches should be cut to this size.

Lay out the patch pieces on a sheet of plastic and wet them thoroughly with G/flex® 650 epoxy resin. Brush both surfaces of the canoe with the G/flex, taking care to work the adhesive into the scratches and small dings. Finally, mix 406 Colloidal Silica with the residual adhesive in your cup to make a thickened mixture suitable for filling the holes and cutaways in the canoe.

Apply adhesive to the patches

To apply the adhesive to the patches, start by brushing both surfaces of the canoe with the G/flex 650 epoxy, taking care to work the adhesive into the scratches and dings. You can use a thickened mixture of 406 Colloidal Silica with the residual adhesive to fill any small holes and cutaways around your repair.

Next, lay the patch pieces on plastic and wet them thoroughly with the G/flex 650. For the outside of the hole, apply a single patch and smooth it into the thickened mixture. Stack up the inner patches and use a squeegee to ensure no air is trapped. Centre the stack of patches over the hole on the inside of the hull and carefully lay it into place, again using a squeegee to remove any air.

Check the placement and shape of your repair, and leave it to cure overnight. The following day, you can ground the edges of the patches to remove any roughness and apply a mixture of G/flex 650 and 407 Low-Density Filler to fair the patches inside and out.

Smooth the patches into place

Smoothing the patches into place is an important step in repairing a hole in an aluminium boat. After applying the single patch over the outside of the hole and smoothing it into the thickened mixture, you will need to stack up the inner patches. Squeegee the patches to ensure that no air is trapped, and centre the stack over the hole on the inside of the hull. Once the patches are in place, carefully lay them down and squeegee over the area lightly to remove any remaining air. Check the outside of the hull to make sure that the pressure on the adhesive in the holes is not pushing the outer patch out of place. When you are satisfied with the patch placement and fairness, leave it to cure overnight.

Leave to cure

Once you have applied the filler, adhesive, or epoxy to the hole in your aluminium boat, it is important to give it time to cure. The amount of time this takes will depend on the product you are using, so be sure to read the instructions carefully. Some products may require an overnight cure, while others may need up to 72 hours.

During the curing process, it is important to leave the boat undisturbed so that the filler or adhesive can set properly. Make sure that the boat is stored in a safe, dry place where it will not be disturbed. If possible, try to store the boat upright so that the filler or adhesive can dry evenly.

Depending on the product, you may need to carry out some light sanding or other preparation work to the surface of the boat before the filler or adhesive is fully cured. Again, refer to the instructions of your chosen product for guidance on this.

Once the filler or adhesive has cured, you may need to apply a primer or paint to the repaired area. This will help to protect the repair and ensure that it is watertight. Follow the manufacturer's instructions for drying times and application methods for these products.

Finally, once all the necessary coatings have been applied and cured, you can test your boat on the water. Remember to take it easy at first and avoid any sharp knocks or impacts that could damage the repaired area. With proper care and maintenance, your aluminium boat should provide many more years of enjoyable use.

Frequently asked questions