Aluminum is an amazing material that can be found in almost every industry, but because of its lightweight and durability it is especially well suited for marine applications; boats in particular. There is an entire class of boats specifically made from aluminum that are light and relatively small, often for personal use. Many of these boats are designed specifically for fishing, but the truth is this metal can be found in ships of all shapes, sizes and uses.
Today, we’ll be looking at the most common uses of aluminum in boats and other watercraft and what you should consider before selecting an aluminum alloy for use in a marine environment. If you have specific questions about one of our product lines, don’t be afraid to reach out and we’ll be happy to answer them.
What attributes make aluminum well suited for boats?
Aluminum is famous for being lightweight. It is prized for all sorts of applications in many industries specifically for this reason. While it is not the lightest metal (that distinction belongs to magnesium), when you combine its lightweight with its excellent strength-to-weight ratio, then you have a material that is not only incredibly light, but also amazingly strong. This is a combination that makes it perfect for boats and other watercraft.
But there’s more to aluminum than just being strong and light. Another essential characteristic of this metal when it comes to marine environments is its excellent corrosion resistance. There are many alloys that have been developed with corrosion resistance specifically in mind, but aluminum already has a head start over others because of the natural oxidization process it undergoes. All aluminum routinely reacts to the oxygen in the air to create what is known as a passivation layer. This thin surface layer offers aluminum protection from further oxidation, and even repairs itself should it be scratched.
Furthermore, with boats intended for saltwater there are certain alloys, such as 5083, that are especially well suited to protect against corrosion caused by chlorides. It’s also possible to add coatings that further bolster an alloy’s protective capabilities, though this is often not necessary with aluminum.
Another factor that makes aluminum ideal for boats is its ease of fabrication. Building boats and ships requires large pieces of metal shaped for the hull and other parts. Aluminum is the perfect choice because it is easy to work with and can be shaped as desired. This not only makes the manufacturing of aluminum boats faster, but also cheaper than many other metals.
Aluminum is a better choice for lightweight boats than fiberglass
The other material that is most likely to be found in modern small boats instead of aluminum isn’t metal but fiberglass. While most people are familiar with it there is a great deal of diversity when it comes to fiberglass materials used for boat hulls. This is an obvious advantage, as is the fact that fiberglass can be shaped rather easily and fitted to any design. While fiberglass has a long history of being used in boats for several reasons, aluminum is becoming a primary choice.
Aluminum is stronger than fiberglass. This may not seem important if you assume that all a boat’s hull needs to do is keep the water out, but any boat owner knows that a hull must withstand a great deal of a wear and tear over its lifetime. Not only are there the normal bumps and scrapes a small boat will endure while docking and being transported, but in the case of an accident, heavy weather or other mishap, boats will occasionally run aground. This can be extremely damaging to a hull and requires a strong material such as aluminum to avoid catastrophic damage.
Which alloys are best for small boats?
When it comes time to select an alloy, you have many grades to choose from. While the options can be intimidating, it means that you can always find a material suited to your needs. This is true of boats, because there are many different parts that can be made with aluminum in addition to the hulls, and each one will have specific requirements.
The 5XXX family of aluminum alloys is among those most commonly used on boats. As already mentioned, these alloys are recognized for their excellent corrosion resistance. Tests with seawater exposure indicate that even after ten years of use, the tensile strength of these alloys will only be reduced by 2 to 5 percent. In addition, the 5XXX alloys offer weld yield strengths between 100 and 200 MPa along with good weld ductility. The most likely alloys from this series to be found in marine applications are 5052, 5083, and 5086.
Another popular group of alloys for marine applications is the 6XXX series, though they exhibit lower corrosion resistance than the 5XXX grades mentioned above. 6061 and 6063 have average corrosion resistance when exposed to seawater. 6061 is one the most common aluminum alloys in any industry and is a top choice for boat hulls thanks to its high strength. 6063 has good formability and suitable for anodizing.
What is a non-production boat?
It has become popular among hobbyists to build what is known as a non-production boat. These are custom designed and built boats that are often homemade. There are also small production houses that will design and build custom boats to your specifications. Aluminum is an excellent choice for such boats because of its ease of fabrication and tremendous versatility.
When building out a non-production boat, one of the most important considerations is durability. This is another reason to choose aluminum. When compared with fiberglass and other materials, aluminum lasts longer, withstands damage from impact and corrosion better, and retains its appearance over time. That is not to mention that aluminum is highly recyclable so there is little material wasted during production.
No matter what type of boat you desire: motorboat, sailboat or dingy, aluminum is a great option. There’s no better material supplier than Clinton Aluminum. Contact one of our friendly and knowledgeable representatives today if you have any questions, concerns or inquiries.
