There Is A Good Reason For Composite-Fiberglass
There are two technologies used in the construction of ice-water airboats:
Composite Hull - Used in the construction of ALL airboats from 1000 Island Airboats
The term fiberglass is itself somewhat misleading, as it describes just one component of what is actually a composite material. The other component is a plastic vinyl ester and sometimes epoxy. Thus, the more accurate term is fiberglass-reinforced plastic (FRP) or glass-reinforced plastic (GRP).
The principle behind any composite building material is simple. A binding medium, stiffens and makes stronger a very strong fibrous material. For example, if you mix concrete and steel together, you can build quite a strong house. The sum is much stronger than its parts. In this case, the medium is the resin, and the stiffening fibers are spun glass, graphite and filaments ten times thinner than a single human hair and much lighter than concrete and steel. These fine glass fibers individualy are extremely strong and when held together by plastic resin they form super tough ridged light shapes that can stand flexing and are easy to work with. You can cast almost any shape. A huge advantage for an ice water boat hull design.
The resin begins as a liquid and becomes solid after a catalyst or hardener is added to it. This is a chemical reaction that cannot be undone. Thermosetting plastics like polyester, vinyl ester, and epoxy become permanently solid after setting. They are light, super strong, tougher than aluminum, stand up to flexing and anyone can repair them easily and cheaply. Aluminum gets brittle when cold, aluminum breaks next to its welds after flexing a few times and takes skilled craftsmen, special welders and a proper environment to repair or modify.
Aluminum hulls are created by taking flat panels of aluminum, cutting to specification and welding them together. The misconception is that aluminum is lighter and stronger than composite. This is NOT the case. Composites pound for pound are stronger and have higher impact resistant than aluminum. Ice water boats need to be resistant to point loading. Aluminum ice water airboats have to be made from heavy gauge aluminum sheet and have lots of reinforcing to try to resist puncture and stop flexing. A proper Aluminum ice water rescue boat can weight 1.5 to 2 times a composite boat size for size and will last as short as one season before hull maintenance becomes an issue. 1000 Island Airboats made 27 years ago still operate at low costs.
A big weight disadvantage of aluminum-built airboats with flat bottoms is DRAG. This creates a huge issue when traveling over ice, snow, slush etc. The issue of DRAG increases the dangers of ice/water transitions. Flat bottom airboats for ice usage are much less maneuverable, require more power, and tend to "snowplow", further adding to performance issues. This snowplow effect can crush anyone in broken ice during rescue. They are so heavy that they can’t climb over pressure ridges. Another concern is metal fatigue when operating on solid ice in subzero temperatures. Please read more about this by clicking on the PDF Symbol below.
The following was stated by an aluminum airboat industry expert on the use of aluminum airboats on ice.
"I'm not sure about all the USCG airboats. I know they've used several different manufacturers over the last few years, trying to find one that'll hold up to their mission profiles on the Great Lakes. From what I hear from USCG, they're destroying the boats after one season, while destroying the structure inside. Extreme vibration and shock, stress and extended operations is wreaking havoc on welds"
Click the PDF symbol below to view additional side by side comparison.