- The marine environment is a harsh one; wood swells and cracks, fiberglass gradually flakes apart or warps, steel rusts when the paint peels away. Aluminum is subject to denting but is also lightweight and corrosion resistant, making it ideal for boats where weight is especially critical. A small aluminum boat can navigate in less than one foot of water with an air boat needing only a few inches of depth to operate.
- Aluminum boats are built from cast, stretched, or rolled pieces of aluminum which are shaped and welded together. The welded seams are stronger than the surrounding metal and weld ruptures are rare. A coat of paint or epoxy may be added to reduce corrosion, with an aluminum oxide finish used on less expensive models.
- Constant exposure to moisture, vibration, and salt weakens metal over time. Boat-type aluminum is alloyed with about two percent magnesium along with small amounts of copper and chromium to improve corrosion resistance and the hardness of the metal. 5052 Marine aluminum is an industry standard for these small craft, and it can withstand 28,000 to 40,000 pounds of pulling stress before breaking.
- Marine aluminum is a stout meta,l allowing the hull to be rather thin. A typical 12 to 16 foot aluminum boat has a hull thickness ranging from 0.046 to 0.071 inches, or about the thickness of 8 sheets of paper.
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