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Marine environments present various challenges, including corrosive saltwater and biofouling. Vessels and boats, therefore, require durable materials that can withstand harsh conditions without frequent maintenance. Aluminum extrusion profiles are a reliable solution in this context. If you want to know more about marine aluminum extrusions, their benefits, and applications in marine environments, let’s start!
Common Marine Aluminum Extrusions Types
Aluminum profiles are produced by extruding aluminum, and manufacturers use heat and pressure to produce top-quality marine aluminum profiles. Some common options include:
5000 Series
- 5083: The 5083 aluminum is a high-strength, non-heat-treatable alloy that contains 4.0–4.9% magnesium. They are popular for their exceptional corrosion resistance and are used in bulkheads, stringers, and hull frames.
- 5086: If you want something durable and weldable, the aluminum extrusion profiles 5086 are ideal. They contain 3.5% to 4.5%, and you’ll commonly find them in stiffeners, deck supports, and superstructures.
6000 Series
- 6061: The 6061 marine aluminum extrusions are precipitation-hardened alloys having magnesium and silicon as their primary alloying elements. They have good structural strength, high machinability, and excellent corrosion resistance. Commonly, this grade is used in marine equipment frames, railings, and fittings.
- 6062: For lightweight marine designs, the 6062 aluminum extrusion profiles are good as they can resist saltwater corrosion. This grade has high tensile and yield strengths, enabling the equipment to withstand heavy loads without failure.
Why Is Aluminum Used in Marine Environments?
Now that you are aware of the top marine aluminum extrusions that you can use, here’s an overview of their benefits and why they are worth the investment:
Durability
Marine aluminum extrusions are corrosion-resistant by nature as they form a protective oxide layer. Hence, the material underneath stays protected from saltwater damage, pitting, and galvanic degradation.
Safety
In marine environments, accidents such as fires can occur at any time, requiring materials that ensure safety. Happily, marine aluminum extrusions provide exactly that. They don’t burn, and there’s no risk of fumes or smoke, making them a top choice for vessel construction.
Design Flexibility
The extrusion process of aluminum is pretty much like squeezing toothpaste from a nozzle, so manufacturers can use it to create intricate shapes. For instance, it can produce features such as ribs, channels, and fastener points that enhance functionality and simplify the assembly of marine equipment.
Environment-Friendly
Aluminum extrusions also get the limelight since they can be recycled infinitely without losing their quality. This uses 95% less energy than primary production processes, reducing waste and overall greenhouse gas emissions.
Surface Treatment for Marine Use
Pure aluminum extrusions without any surface treatments can get worn out quickly when constantly exposed to marine environments. Here’s an overview of the top surface treatments they go through to enhance their lifespan and performance:
- Marine Grade Anodizing: The anodizing is an electrochemical process that involves thickening the natural protective oxide layer. Aluminum is immersed in an acid solution, and an electric current is applied to strengthen the surface coating. This coating is wear-resistant, making it ideal for marine applications.
- Powder Coating: Aluminum powder coating is an eco-friendly dry-finish process that applies a protective, colorful layer to extrusions. Electrostatic sprayer, colorful pigments, and powdered resins are all part of this process, providing a barrier against saltwater.
- Chrome Plating: Marine aluminum extrusions are first cleaned and then dipped, sprayed, or brushed with a solution containing chromium salts. The coating varies in color from transparent to yellowish or iridescent. Manufacturers either only go with chrome plating or add further protection layers like anodizing to enhance protection against marine weather.
- Painting: Aluminum extrusions are also painted to maximize their durability. In this, the material is first cleaned to remove dirt and grease. A primer is applied, followed by a layer of paint that provides a unique color and finish. Typically, polyurethane paints are used as they perform better under UV light and harsh chemicals.
Typical Marine Applications
The applications of marine aluminum extrusions are diverse, ranging from deck supports to framings and superstructures. Let’s discuss these in detail:
Hull Structures
Marine aluminium extrusions are quite commonly used in hull frames, longitudinal stringers, and bulkheads. If you want customization, you can also use it to make stiffening ribs that greatly contribute to the structural integrity of the hull.
Shipbuilding Components
Shipbuilders worldwide rely on aluminum extrusions to create durable decks, fittings, and superstructures. They enjoy benefits including better fuel efficiency and enhanced ship lifespan.
Onboard Infrastructure
All the onboarding infrastructure, from stairways to railings and even ladders, is made using marine aluminum extrusions due to their high strength and durability.
How to Maintain Marine Aluminum Extrusions in Corrosive Saltwater Environments?
Although aluminum extrusions are durable, they still require high maintenance to keep them pristine and functional for a long time. Here are some tips that help you with the upkeep:
- Frequent Cleaning: The very first thing you should adopt is the regular cleaning of the equipment after every use. This removes salt deposits and grime that accelerate corrosion over time. Use mild, pH-neutral, and non-abrasive detergents along with a soft sponge. Don’t rely on acidic solutions that may break down the protective oxide layer.
- Renew the Coatings: Most marine extrusions have a protective coating that experiences wear and tear after frequent usage. You should also renew the coating every 2 to 3 years, depending on the usage and visual condition.
- Store in a Dry Area: When not in use, store the vessel in a dry, well-ventilated area to prevent permanent moisture buildup in crevices.
Some other things that you must do include not allowing direct contact between aluminum and dissimilar metals, whether stainless steel or iron. Perhaps, you can also add a sacrificial anode, like zinc, to absorb electrolytic processes and eliminate the risk of galvanic corrosion.
Conclusion
Marine aluminum extrusions relieve the stress of both shipbuilders and end customers due to their versatility and longevity. If you are struggling to find desired aluminum profiles, contact Conglin Aluminum today! We have over 30 years of experience and global recognition that make us a trustworthy partner for all your projects.
