Ping: Short Wave
"Tim" wrote in message
...
Eisboch wrote:
"Tim" wrote in message
...
That's a very nice looking craft from what I can tell, but I wonder
what "Marine grade aluminum" is?
Some type of alloy? And I wonder how it would hold up to yearsa of
salt water and electrolysis?
Aluminum is made in many different alloys to achieve certain general
characteristics. I think the RockSalt boats are made of a series 5000
alloy
which has desirable attributes such as strength, weldability, and
corrosion
resistance, particularly in marine applications.
Aluminum in general is a "self sealing" metal in terms of corrosion
resistance. If you scratch aluminum hard enough to get to the raw
metal,
it quickly reacts with oxygen to form aluminum oxide on the surface of
the
fresh metal. If I remember correctly, about 50 angstroms will form
almost
immediately, then continue to build over time until the metal molecules
are
no longer in contact with oxygen and the oxide barrier will stop growing.
BTW, aluminum oxide is non-conductive. That doesn't mean the boat won't
conduct electricity because the oxide layer is relatively thin (few
microns)
and will break down at a high enough voltage. Often, though, low voltage
(like 12 volts) connections are difficult to properly make unless you
scrape off the oxide and make the connection before the oxide rebuilds.
Eisboch
I think that was kind of a problem with older Starcrafts, wasn't it?
I've seen many a Starcraft that was welded and patched upon. But at
least you could weld and patch them fairly easily.
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