Many of the docks we manufacture and sell are made of marine grade aluminum, but what exactly does that mean and why do we use it? Marine grade aluminum alloy is a type of metal perfect for marina settings. The most common semi-fabricated aluminum products fall in the 5000-6000 series of the aluminum series. Although the 5000 series is considered a marine allow, it is much softer than the 6000 series. They have interesting mechanical characteristics, which allow them to be deformed at low temperatures and the best part, they resist corrosion.
Not surprisingly, salt water and sea air found in the marine environments attack metals, wood, plastic and brick. In order to prevent corrosion, a marine grade aluminum alloy was developed to resist these factors. Another type of corrosion, galvanic, is very common in marine environments. It occurs when two (or more) dissimilar metals are brought into electrical contact under water. The use of stainless steel nuts and bolts and aluminum alloy together can create a galvanic corrosion, however, because the ratio of steel to aluminum is so small, the result is virtually none. If the ratio was reversed, the result would be very different.
This relatively light metal can be formed into shapes with higher moments of inertia than its heavier counterparts like steel, although the 6000 series is a little more difficult to form, so we primarily use extrusions for the construction. They’re built to withstand heavier weight loads for many years.
Using aluminum alloy allows us to create gangways, docks and ramps with superior loading capacity. They come totally maintenance free, allowing you to spend less time repairing, reinforcing or cleaning, and more time on your boat or dock. Because of aluminum’s extreme lightweight, aluminum boat docks and gangways are easier to move. For installation or relocation, aluminum is 1/3 the weight of steel, allowing you to expend less time and energy when you need to make move it. Every boat owner needs a dock, and marine grade aluminum alloy has some of the biggest advantages compared to other materials.