Choosing material for a small vessel is always about finding a trade-off between weight, strength, cost and durability. metal boatAluminum is consistently at the top of the preferences of experienced water-engineers, a metal that combines lightness, corrosion resistance and the ability to create complex contours of the hull, making it an ideal candidate for building or buying a reliable boat.
But the simple phrase “aluminum boat” is not enough to make a good decision. There are many alloys, processing technologies and design solutions that dramatically change the performance of the vessel. The wrong choice can lead to the boat being too heavy, not repairable in the field, or, conversely, too soft and vulnerable to impacts on rocks.
In this article, we will discuss in detail which brands of aluminum are used in shipbuilding, how they differ from each other and what to look for when buying or ordering at the plant. AMG It is so popular than duraluminium in water and how to prolong the life of your boat, observing simple rules of operation.
Why aluminum: the key advantages of the material
Aluminum has become the de facto standard for small fleets for a reason: it weighs about three times less than steel, making it possible to build boats with excellent performance and efficiency even when fitted with medium-powered engines. It also makes it easier to transport on a trailer and launch without heavy machinery.
Besides, aluminum-boat They're highly corrosive, and an oxide film forms on the surface of the metal instantly, which protects it from further destruction, and unlike steel, aluminum doesn't rust in the conventional sense, although it's susceptible to electrochemical corrosion when it comes into contact with other metals in salt water, which is solved by zinc treads.
Remainability is an important aspect. With the skills and equipment, you can fix a hole or replace a burst seam even far from civilization, which is critical for fishing and expeditions to hard-to-reach places. Metal is not afraid of ultraviolet light, temperature changes and mechanical effects that could be fatal to fiberglass or PVC.
When buying a used aluminum boat, be sure to check the docking places of the transom and bottom - it is there that fatigue cracks most often occur.
Major alloys: AMG vs. Duraluminium
The most common question that arises from the buyer: which alloy is better? in domestic shipbuilding historically divided into two main groups: aluminum-magnesium alloys (series). AMG) and duraluminia (series) D16TUnderstanding the difference between the two is a guarantee of the long service of your vessel.
Alloys AMG (e.g., AMG5, AMG6) have excellent weldability and high corrosion resistance, are plastic, bend well and do not require complex heat treatment after welding, and are the basis of most modern boats, because this material forgives errors in operation and is easily repaired by argon welding.
DuraluminiumD16T) is much stronger and harder, but has some serious limitations, it is prone to intercrystalline corrosion, especially in welding areas, so duraluminium structures are mainly assembled on rivets, and is justified where maximum rigidity is required with minimal sheet thickness, but in aggressive aqueous environments it requires careful care.
What is "marine aluminum"?
In the context of boats, sea aluminum is usually understood as 5xxx series alloys, such as the AMg5 or the imported 5083, which have maximum resistance to salt water and are not susceptible to corrosion cracking under stress.
Comparative table of specifications of alloys
To organize the information and help you make the right choice, we have prepared a comparison of the main specifications of popular shipbuilding alloys, these parameters affect the final cost of the boat and the conditions of its operation.
| Parameter | AMG5/AMG6 | D16T (Duraluminum) | AMC (Aluminum-manganese) |
|---|---|---|---|
| Strength | Medium/High | Very high. | Low. |
| Corrosion resistance | Great. | Requires protection. | Good. |
| Weldability | Great. | Bad (only rivets) | Good. |
| Plasticity | High. | Low. | Very high. |
| Application | Boat hulls, boats | Spangouts, power elements | Superstructures, coke. |
As you can see from the table, AMG5 is the most universal solution It combines sufficient strength with manufacturability, allowing for reliable structures without the risk of rapid destruction from contact with water.
Design features and welding
The technology of connecting parts determines not only the strength, but also the tightness of the boat. argon-arc weldingThis process requires a high skill welder and the use of an inert gas (argon) to protect the molten metal from oxidation.
The quality of the seam is critical. Indigestion, pores or cracks can lead to leaks that are difficult to detect early. A good weld should be uniform, without sharp transitions or cuts. Often, overhead elements or double seams are used to strengthen the structure in areas of high loads, for example, on the cheekbones and in the area of the transom.
☑️ Quality check of the welding of the shell
It's worth noting that welding heat changes the structure of the metal in the seam area, reducing its strength, so when designing a boat, certain reserve factors are laid down, and using automatic welding in factories allows you to achieve a more stable result than manual work in garage conditions.
⚠️ Warning: Never try to cook duraluminium (D16T) with conventional argon without further heat treatment - such a seam will be brittle and quickly break down under load. Dural requires riveting!
Corrosion protection and maintenance
Although aluminum doesn't rust like iron, it's susceptible to other types of corrosion. galvanicThis is caused by the contact of aluminum with nobler metals (copper, brass, stainless steel) in the electrolyte (water) and can quickly "eat" the body at the point of contact.
To prevent this process, all submarine parts and engine attachments must be insulated. Stainless bolts are permissible, but it is advisable to lubricate them with special compounds or use gaskets. In salt water, zinc treads are mandatory, which take corrosion action on themselves, sacrificing themselves to preserve the hull.
Regular maintenance also includes freshwater washing after each exit, especially if you have been swimming at sea. Salt deposits are hygroscopic and can cause localized corrosion. Periodic treatment of the bottom with antifouling compounds (compatible with aluminum!) will prevent algae from fouling, which also contributes to corrosion.
The main enemy of the aluminum boat is not the water itself, but the wrong neighborhood with other metals and wandering currents.
Tuning and modernization of aluminum boats
The aluminum case provides a wide range of upgrades, the owner can weld new knives, strengthen the transom under a more powerful engine or install additional struts. Metal holds the load well, allowing you to install heavy attachments without the risk of deformation.
A popular type of tuning is installation hydrofoilThey also often change the standard seat to a more comfortable seat with swivel mechanisms, aluminum makes it easy to drill holes and attach elements to bolts, if you follow the rules of sealing.
However, it is worth remembering that the extra holes in the bottom are potential points of corrosion and leakage, and any improvements related to the violation of the integrity of the housing below the waterline should be carried out using quality sealants and sealants designed to stay in the water.
⚠️ Attention: When drilling holes in the aluminum board, be sure to use sharp metal drills and low revolutions, so as not to overheat the material and not deform a thin sheet.
FAQ: Frequently asked questions
Can an aluminum boat be painted with ordinary paint?
Conventional paints are poorly maintained on aluminum due to the oxide film. You need to use special soils for non-ferrous metals (for example, zinc-based) and epoxy or polyurethane paints intended for boat applications.
What is the life of an aluminum boat?
When properly operated and without serious accidents, an aluminum boat can last 30-50 years or more, and the metal does not age with time, as some composites do, and can be rebuilt if necessary.
Is aluminum afraid of hitting rocks?
Aluminum is plastic. When hit hard, it will remember rather than crack (unlike fiberglass); dents can often be repaired while keeping the seam tight, but thin bottoms (less than 3 mm) are easier to penetrate than thick plastic.
Do I need to dry the boat after every fishing trip?
It is advisable to dry the interior compartments and scoop water out to avoid moisture accumulation and electrochemical processes, especially if the boat has steel elements (anchors, chains).
Which is better: a riveted or welded boat?
The welded boat is airtighter, lighter (no sheet overlaps) and more modern. klepanaya (from dural) is stronger to tear, but heavier due to design and requires replacing seals over time. For most users, welded AMG will be the best choice.