Titanium vs other metals

Discussion in 'Boat Design' started by Stumble, Jun 5, 2012.

  1. BMcF
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    BMcF Senior Member

    Breaking News...sorta. I attended a presentation just yesterday evening where qualitive results were presented on progress to date with a USN pilot project underway at a gulf coast yard to build a pretty large section of a "typical' high performance ship hull entirely out of titanium.

    Key findings to date:

    Welding has reportedly been no problem at all. "Re"-training welders already familiar with GTAW and GMAW welding procedures for stainless and aluminum was no big deal.

    Friction stir-welding works and is being used for flat panel butt welds.

    Welding production overall (in inches per minute) has been increased 8-fold since the start of the pilot project.

    A titanium alloy has reportedly been selected or developed (not sure which...or some of both?) that costs only 30% (?) of the initial material estimates made before the project went ahead.

    Good stuff. I'm especially interested to hear/learn more about this "new" alloy that reportedly costs so much less.
     
  2. Stumble
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    Stumble Senior Member

    BMcF,

    It is actually the University of New Orleans that is doing this research (about 5 miles from my house). I knew about the stick welding advantages they have developed, but as I understand it, the best applications are really in large part welding, like boat hulls. There is actually a mega-yacht company here that is planning on manufacturing all titanium hulls for yachts, and the navy is investigating it for use as a ship material as well.

    I don't know about a reduced price alloy, but there certainly could be. However from what I have seen (and remember I started as a salesman for Allied after this thread was started), the primary driver for price is not the materials, but the machining costs.

    For instance we make a titanium anchor swivel. It's a complicated part to machine, and takes a good bit of shop setup to make the parts. But once the shop is set for it, making the second is much cheaper. So if I sell you one of them (for 3/8 chain) the cost would run about $700. On the other hand if I sell you 100 of them, the cost per part drops to around $220. If the price is for a wharehouse or commercial reseller i can get the price down to $180 or so. Since a stainless comperable would run around $170 (retail), we are getting close. The only question is who needs 100 titanium anchor swivels?

    This is pretty true across the board. If you want custom stainless machining done, we can probably come close to the cost making it out of titanium. We will be more, but not a whole lot more. On the other hand there are thousands of stainless anchor swivels sold each year, last year we sold one titanium one.

    So if this project is going to buy huge quantities of titanium the cost to manufacture it goes down, as the quantity goes up. This cycle has already occurred with stainless, but is just starting with titanium.
     
  3. spidennis
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    spidennis Chief Sawdust Sweeper

    West Marine? Bass Pro Shop? etc ...... sold only one anchor? I gather that's why they hired you!
     
  4. Stumble
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    Stumble Senior Member

    That's the plan. I was brought on board to be both their in house attorney, and act as a marine specalist for them. So hopefully we can get some traction getting these things stocked in retail stores. Most people recognize the desirability of titanium, but there is so much misinformation, and partially true but controllable concerns that it is hard to gain traction.

    At least for now though I have a major sail maker considering using our bits... Not bad for a week on the job.
     
  5. spidennis
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    spidennis Chief Sawdust Sweeper

    when the time comes I'll have one of these anchors on my wish list for my schooner rigged adventure racing folding proa!
     
  6. MechaNik
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    MechaNik Senior Member

    What would help get traction would be to have some of the major rigging companies using the fasteners. Much of the metal they use is already far superior to 316 stainless, but some fasteners Ti might be a nice touch. Rigging doesn't seem to have much of a price limit.
    You could try the likes of Southern Spars and Ocean yacht systems, but be ready to supply good mechanical data especially that associated with fatigue.
     
  7. Stumble
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    Stumble Senior Member

    MechaNik,

    Some of them already have been using titanium to some extent since it doesn't have nearly the galvanic problem with carbon fiber that stainless does. That being said the move to fiber rigging over time is going to eliminate metals from rigging, regardless of what type. Personally I think the long term use of any metal is quationable in rigging, except for titanium turnbuckles.
     
  8. MechaNik
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    MechaNik Senior Member

    Not quite so Stumble. On these yachts (not the race boats) there is a lot of gear mounted on the rig....lights, radar, gps, satellite domes, vhf..... it goes on.
    The crews go up these rigs and polish the lot, if they had the option to use titanium I can't how they could refuse over price.
     
  9. TeddyDiver
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    TeddyDiver Gollywobbler

    Any keel bolts? :)
     
  10. Stumble
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    Stumble Senior Member

    Hmm, I hadn't thought about that, but thanks. I will have to look into seeing what we can do with those parts.
     
  11. souljour2000
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    souljour2000 Senior Member

    Stumble..so what about wire rope for shrouds/stay...? Titanium wire rope that lasts twice as long and is stronger I think would be a big seller in the sail community vs. old stainless..
     
  12. Stumble
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    Stumble Senior Member

    I actually just checked one this Friday. We don't currently have them in our database, but we can make them up to 12" diameter. We also have a range of nuts to match.

    This was one of my first thoughts when I read about a boat loosing its keel this week. Too many keels are compromised by using 316 in an environment it is just not suited for...
     
  13. Stumble
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    Stumble Senior Member

    There are some practical issues that would need to be addressed, and many of them would take an engineering firm with the willingness to do some experimentations...

    1) can we get a license from Norseman to make their fittings in titanium? If not you put large masses of titanium (more noble) into contact with small masses of stainless (fittings). This is a corrosion nightmare, and I would recommend avoiding it if at all possible.

    2) if we cant get the license, then someone would need to investigate the use of crimp fittings on titanium. I don't know what the engineering back ground on this is.

    3) I know titanium is significantly lighter and stronger (both yield and tensile) than 316. To make this switch reasonable you should reduce the size of the wire to take advantage of these properties... But what would be recommended in this situation is beyond me.

    4) what other mechanical properties need to be considered? Fatigue, creep, stretch at breaking, the engineering is way beyond my capability.

    It certainly is intriguing... We should be able to cut the weight of stainless rigging by more than 50%. I would guess around 70% once everything is redesigned for the different material, and the corrosion allowance is taken out. And theoretically it should last forever once done since there is no corrosive process that attacks titanium in this type of application.
     
  14. Angélique
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    Angélique aka Angel (only by name)

    << I've moved this post from a related thread >>​

    Ms. Lilian (China) says she has some, give her a call or drop her an e-mail and please let us know - link - link - ‘‘nobody buy’’ . . . :confused:

    [​IMG]

    [​IMG]

    Good luck !
    Angel
     

  15. ChrisSR
    Joined: Jun 2012
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    ChrisSR Junior Member

    Hi Stumble,

    I have always understood that Ti was too brittle for most boat fittings. Yield and failure points being too close together.(i.e. No give just a ping) We used to use hot-dip galvanized steel then stainless steel came in. It was said to be so much stronger. We had failures if the metal could move at all due to its low fatigue tolerance. So by the time you beefed it up, you had not saved any weight, only introduced corrosion with your aluminium. The way I understand it Ti has even less tolerance to fatigue, and will corrode your al. even faster.(higher electrical potential difference)
    I am interested in using Ti but need to learn how to without courting failures.
    Cheers,
    ChrisSR
     
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