How to Weld Your Leaking Aluminum Boat at Home

It can be discouraging to be the owner of an aluminum boat and find that it has started to leak. Usually it is tolerated for a while but eventually a leaking aluminum boat becomes a real nuisance due to water accumulating that eventually has to be bailed out by one means or another. There are a number of ways to make both temporary and permanent repairs to an aluminum boat. Various epoxy and RTV type compounds can do a credible job as does fiberglass. The continuous flexing of the aluminum is often the limiting factor in these types of repairs. They usually are not as durable as welding or brazing the aluminum to eliminate the leak. Before making such repairs the owner should think about how long they plan to keep the boat and how much money they want to spend on it.

Perhaps the most durable, permanent, and expensive approach to repairing a leaking aluminum boat is to take it to a shop that does aluminum welding. Typically this can be relatively expensive compared to welding your aluminum boat at home. If you decide to take this approach you can often reduce the cost by identifying where the leak is occurring prior to taking it into the shop.

Find the Leak

Regardless of where you are going to get your aluminum boat welded you will need to find the precise location of the leak. In general a pinhole leak or small fracture in the aluminum skin is easier to work on then a leak occurring at a riveted joint where sheets of aluminum are joined. If a rubber or other flexible gasket is observed it is probably not a good candidate for welding since the rubber will tend to deteriorate under heat and make the leak even worse or contaminate the weld. In those cases a mechanical repair such as swaging the rivets or using a curing type leak sealing compound such as 3M 5200 is recommended.

Read Up On and Select an Aluminum Welding Rod

Fortunately there is a number of aluminum welding products that are inexpensive and can be used to permanently weld a leaking aluminum boat at home. These products are advertised as aluminum welding (or brazing) rods that enable one to use a common propane torch to repair a leaking aluminum boat at home in addition to making repairs to other aluminum items. In addition some brands of the rods will allow welding of copper and brass to aluminum.

Gather Your Parts

When working with these welding rods you are basically brazing the aluminum using a common propane torch. The requirement is to be able to bring up the temperature to 732 degrees Fahrenheit. You must heat the aluminum to 732 degrees F and not the welding/brazing rod directly. This is a step that takes care since the heated aluminum will form an oxide that floats on it's surface plus you have to make sure you don't apply the torch directly to the aluminum for too long of a time and burn a hole through it. To help clean off the oxide it is often recommended that a stainless steel brush be used so as not to contaminate the aluminum.

Develop Your Technique

The actual step of welding using these rods has been described as scraping the metal to be welded using first the stainless steel brush then the welding rod. Once again you need to be very careful not to melt the aluminum skin itself. You can tell when the aluminum is too hot when it transforms quickly from a dull metallic solid to a shiny metallic liquid. When welding keep the torch and rod moving around and wiping the area to be repaired until you build up a sufficient thickness to seal the leak. It is best to practice the welding technique on some aluminum sheeting that is about the same thickness as what you are trying to repair. Since aluminum conducts heat rapidly you should also try to duplicate the size of the aluminum you are repairing which can be challenging when welding an aluminum boat. While it may not be representative of welding a hole in an aluminum boat, punching a hole in the bottom of an aluminum soda can and welding it will provide a good test of your welding skills.

For videos showing the aluminum welding technique you can go to the websites of some of the vendors. While they may not show an aluminum boat being welded they do show close up examples of the welding technique which can prove very useful.

Money Saving Tip

While you can order the aluminum welding rods online on the manufacturer's website you should check out the aluminum welding rod prices at Harbor Freight stores or on their website. Often times they are lower and if you have a store in your area you don't have to pay shipping or wait for delivery.

Conclusion

Leaks in aluminum boats can be fixed using a number of techniques. For a lasting, economical repair you should consider welding your aluminum boat at home using the specialty aluminum welding (brazing) rods made to be used with your propane blowtorch.