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Thread: Tjm.............Titanium

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    Member Hoyt's Avatar
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    Default Tjm.............Titanium

    Japanese consortium begins construction of all-titanium boat

    An all-titanium fishing boat is being constructed as a project by Nippon Steel Corporation, Toho Technical Service Company, and Eto Shipbuilding Company. According to published reports in the International Titanium Association's newsletter and American Metal Market, the boat will use about three tonnes of titanium.

    The boat will be 12.5 m long and 2.8 m wide, with the deck and structural parts as well as the hull made of titanium. The hull will be 2.5 mm thick as compared to 5 mm for an aluminum hull. In addition to the weight savings, the titanium hull will also be maintenance-free as marine growths that adhere to the titanium hull can be removed easily. Conventional fiber-reinforced plastic and aluminum-alloy ships need painting to prevent the adherence of marine growths.

    The all-titanium ship offers several advantages, according to the developers. It will improve fuel efficiency, eliminate maintenance costs, increase the ship's speed as a result of the reduced resistance of the unpainted hull to the water, and ensure environmental safety as there will be no paint dissolving in the water.

    Engineers from the three companies worked for four months in developing a test vessel before the final decision was made to proceed with the full-scale project. After the performance of the ship has been proven, the group plans to build pleasure boats, yachts, and high-speed police boats as well as fishing boats.

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    Member tjm's Avatar
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    oh baby!.. a Ti riverboat would be pretty cool.....
    ------------------------------------------------
    pull my finger....

  3. #3

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    Anyone priced out TI lately? Those are going to be some spendy boats! They will be able to use thinner material to reduce weight, but still be more rigid and strong than aluminum. I want one.

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    Default corrosion?

    I wonder what problems if any will arise with disimilar metals? Example : aluminum outboard brackets, zinc annodes, etc. Some aluminum hulls in salt have corrosion problems when electrical current isn't dissipated properly and the zinc's aren't up to snuff or even there anymore. Does anyone have any word on how titanium holds up to all those variables?
    It should be interesting how it works out.

  5. #5

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    Titanium produces it's own protective layer of oxidation and constantly regenerates it in the presence of water or oxygen. Other than the material cost, and being a bit more brittle than traditional boat materials, it would make a really nice hull.

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    Default Al vs. Ti

    Aluminum has a modulus (stiffness) of approx 10 and a specific gravity of 168.5.
    Titanium has a modulus of approx 15 and an SG= 280. Ti is twice as strong as Al and only 60% heavier. So you have the same ridgidity in the boat for a 40% weight reduction. Then if you factor in the yield point (strength or how easily it is damaged). Ti's is approx 5 times that of Al. You would have one neck of a boat.

    This is all alloy dependent of course so this is a pretty rough approximation.

    Would be interesting to build an airboat out of it though.

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    Member tjm's Avatar
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    Quote Originally Posted by needcoffee View Post
    Would be interesting to build an airboat out of it though.
    I never thought of that...that would be neat....
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    pull my finger....

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    Smile

    wow you guys know your stuff.........I just thought it was cool!

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    Default $$$$

    Just to put a price tag on it, one 4'x5' sheet of 1/8" 6Al-4V Ti is $2500.00 US. Never mind the cost of extruded members.

  10. #10

    Default Titanium requires special welding techniques, too

    I read up on the use of titanium in boating a couple of years ago. Among other things that increase cost when using titanium is the fact the the weld has to be kept free of oxygen not only at the arc site, but until the metal has cooled down significantly. Building a boat would almost require that the welding be done in an oxygen-free room, (filled with argon or another inert gas under positive pressure), with the welder(s) using supplied air to breathe, and exhausting their breathing out of the room, too.

    It's an awesome metal in many ways--strength per weight and corrosion resistance are both way up there. It is a perfect salt water boat material once you get past the cost.

    Jim

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    Quote Originally Posted by Yukoner View Post
    Just to put a price tag on it, one 4'x5' sheet of 1/8" 6Al-4V Ti is $2500.00 US. Never mind the cost of extruded members.
    Ouch.........................not cheap.

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    Quote Originally Posted by midnightsunfun View Post
    I read up on the use of titanium in boating a couple of years ago. Among other things that increase cost when using titanium is the fact the the weld has to be kept free of oxygen not only at the arc site, but until the metal has cooled down significantly. Building a boat would almost require that the welding be done in an oxygen-free room, (filled with argon or another inert gas under positive pressure), with the welder(s) using supplied air to breathe, and exhausting their breathing out of the room, too.

    It's an awesome metal in many ways--strength per weight and corrosion resistance are both way up there. It is a perfect salt water boat material once you get past the cost.

    Jim
    Among other things, i build custom mountain bike frames, TIG welded, and i've messed about with Ti in frames. Its actually easier and more forgiving to weld than a similar wall thickness of alloy steel, but like you said, its very sensitive to weld contamination by Oxygen. You need to have both sides of the weld purged in an Argon atmosphere (much like Stainless) or contamination will result. Building a Ti hull, man, the Argon $$ alone will kill you, never mind the Ti costs. The boat mentioned, they must have the welders in a large purge chamber.
    Ti is amazing, but it certainly is not perfect. I have seen many cracked Ti mountain bike frames, and in a boat hull, as it is heavier than Aluminum, you would want to reduce hull thickness to keep the weight down. Thinner hull, more chance of damage, and trying to repair the Ti hull, well, better have real deep pockets
    Diamond S makes some very cool snowmobile frames out of Ti. I was going to build one for my last mod sled, but after pricing out the tubing, well, i decided to make a bigger contribution to my RRSP's instead

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