RE: [Paddlewise] Composite vs. Plastic Info - aluminum?

From: Chuck Holst <cholst_at_bitstream.net>
Date: Thu, 27 Feb 2003 14:20:06 -0600
The biggest problem with making small craft from aluminum is that under 
normal circumstances aluminum bends in only one direction at a time, which 
makes it hard to form complex curves -- unless you stretch it using 
explosives forming or something similar. Also, aluminum watercraft are 
typically riveted. That means you need to leave enough room on the inside 
to get at the seams with a rivet gun. That's one of the main reasons 
aluminum canoes have such full ends. One manufacturer of racing canoes got 
around this by welding the bow and stern, which allowed finer lines, but I 
suspect this method of construction would be much more expensive than 
fiberglass. It's not just the welding, but the grinding afterward that 
would make it too expensive for kayaks. The wood and canvas canoes that 
preceded aluminum canoes actually had finer lines. Their main disadvantages 
were weight, absorption of water, and maintenance. The aluminum canoe 
became popular because of its relative lack of maintenance, not because of 
its paddling qualities. Here in Minnesota, and I suspect around the 
country, it has been largely replaced by plastic canoes, both Royalex and 
fiberglass. Grumman sold off their canoe-making business several years ago. 
Like the aluminum canoe, they are relatively maintenance-free, but like the 
old wood and canvas canoe, they -- especially the fiberglass ones -- can be 
shaped with complex curves.

Aluminum canoes have a few other disadvantanges as well. They conduct heat 
-- and cold -- better than plastic, and they are noisy when struck by a 
paddle, hence the nickname, "boominum" canoe. Aluminum also stick to rocks 
more easily than plastic. Also, it is not indestructible -- I have seen a 
few pictures of aluminum canoes wrapped around rocks -- and it is hard to 
repair. And if you were paddling an aluminum kayak that smashed into rocks, 
I think you would stand a good chance of being pinned inside. Polyethylene 
rebounds and fiberglass shatters. Aluminum does neither.

Chuck Holst
^_at_^_at_
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Received on Thu Feb 27 2003 - 14:18:01 PST

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