Peter Wiley wrote in message ...
In article , Joe
wrote:
(Peter Wiley) wrote in message
om...
(Joe) wrote in message
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Peter Wiley wrote in message
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In article , Capt. NealĘ
wrote:
Aluminum is relatively worthless for a boat hull.
All it takes to completely destroy the hull of an
aluminum hulled vessel is a handful of mercury
past smeared on it. It will begin to turn to dust within
hours, break apart and sink.
A stainless steel boat is impervious to just about
anything but strong acids.
Bwahahahahahahaha. It's obvious you know SQRT(f**k-all) about
metallurgy. S/steel is not a good metal to have in continuous contact
with seawater.
My biggest objection to aluminium is that its abrasion resistance is
low compared with steel and its ultimate failure point is too close to
its deformation point. Steel is a lot more ductile but does require
good barrier coats to keep rust at bay.
If money is no object, you build out of cupro-nickel.
PDW
Whats cupro-nickel? And why?
I hear nickle copper is best, the copper is a perfect antifoulant.
http://www.technicalmaterials.com/me...ro_nickel.html
Same stuff, just you got the name wrong. Look it up in Lincoln's
welding handbook and you'll find that you can weld it with MMA using
ECuNi rods, good weldability. Ditto for GMA welding, GTA welding and
fair welds using carbon arc tho why you'd bother is beyond me. Preheat
not required, no fancy techniques needed unlike aluminium or s/steel.
Good mech properties. Pretty much inert so no real corrosion probs and
as you noted, naturally antifouling.
Real problem is the price. Friend of mine's brother is a scrap metal
dealer, got 2 tanks of Inconel one time for the price of s/steel. Wish
I'd have known him back then, I woulda bought them off of him and
saved the sheets for a hull.
Yeah that would have been a great find. We have lots and lots of
chemical and petro plants around here, If i ever feel like building a
new hull.
It would be nice to never have to deal with the hull again. Read
about a 32 footer over in england called the Pretty Penny. Hauled it
for the first time after 20 years with no noticable loss to the hull,
a layer of slime and grass that was easy to simply brush off.
But guess it all depends on the price per sheet.
LME has copper at $3246/tonne, nickel at $14255/tonne. 70/30
cupronickel, call it $6500/tonne. A Q&D calc gives me approx 0.3 cubic
metres of metal in an 11m hull of 4mm plate thickness so that'd be 0.3
* 8.9 (Cu is 8930 kg/m3, Ni 8800 kg/m3) * 6500 = $17K for the hull
plate. Minimum since this makes no allowance for cost of rolling etc
etc.
You might be able to afford it but I can't :-)
PDW
Well My buddy at Farmers Copper in Galveston gave me an American
version.
To build a 42 footer like redclouds hull I will need approx 18 sheets
of 3/16 inch and 4 sheets of 1/4 inch and one sheet of 1" for the keel
board.
About 13,000 pounds. With an order of this size I can have it milled
to my specs. And get a super dooper discount... but it still gonna
average 8.20 a pounds. So thats around 106 thousand dollars for hull
deck and cabin material.
Kinda steep.....but you get what you pay for in the long run IMO.
Just look at some of the crap coming off the assembly lines in the 42
footer range. Pay 300K and get junk.
If I ever think of upgrading I might transfer all redclouds current
rigging, sails,engines ect to a spanking new hull of copper nickle.
Perhaps this stepping stone theory of Bobs has some merit.....
It would be nice to build a boat that you know will be around for
several hundred years if kept in the proper hands. Beats the hell out
of a big ass grave marker.
Joe