New position

Discussion in 'All Things Boats & Boating' started by Stumble, Jun 6, 2012.

  1. Angélique
    Joined: Feb 2009
    Posts: 3,003
    Likes: 336, Points: 83, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    If mixing titanium parts into the rigging doesn't cause much galvanic corrosion problems, or not any at all when taking care of it with a zinc anode, then the shackles must be a major target for you as they are easy to replace and in stainless also suffer from crevice corrosion, just as the chainplates, with the same catastrophic effect when they fail...

    Stainless steel shackle crevice corrosion . . . .

    [​IMG]

    From Practical Sailor about this:
    - Detecting and Dealing with Stainless-steel Corrosion

    And the in above link announced report on titanium in the December 2011 issue:

    - Is Titanium an Everyman Metal?

    - Titanium in the Marine Chandlery

    Last two links only fully for paid subscribers which I'm not . . :(

    Cheers,
    Angel
     
  2. Stumble
    Joined: Oct 2008
    Posts: 1,913
    Likes: 73, Points: 48, Legacy Rep: 739
    Location: New Orleans

    Stumble Senior Member

    Angel,

    We already make shackles in sized that range from 1/4" up to around 3" and can scale up or down if there is a demand.

    And I am sorry the practical sailor articles are pay-wall protected, because the "is titanium an Everyman metal" article was written in responce to a customer of ours who replaced his chainplates with titanium.

    Sadly the second one is a little more critical of titanium, specifically in regard to the cost. Though I happen to think it is mistaken, at least to the severity of the cost difference.

    For instance, our current shackles are machined from blocks of material, which means most of the material is cut away to reveal the part we need. This of course results in a huge amount of wastage that has to be returned as scrap to a mill. In addition machining from billets is a very time consuming process, and takes a lot of man hours to fabricate.

    Once the number of parts ordered gets to a critical mass it becomes justified for us to spend the money to build casting molds. This allows us reduce waste to a minimum, and greatly reduces the amount of man hours required to make a part. In some operations Ti's can reduce the manufacturing cost by 70-80% once the cost of the mold is seperated from the equation. At this point the cost of a titanium part really is just a few percent more than a stainless equivalent (which are almost all cast btw).

    This is the problem introducing titanium into the market. When we can use similar manufacturing techniques as stainless our prices are 15-20% more than a 316 part. But in most cases our volume isn't high enough to really go into mass production. We are slowly getting there with a number of parts, fasteners particularly are already there, but it is a slow process to shift an entire industry to a new material.

    Obviously there are some industries where there just aren't any good alternatives (like the petro chemical industry), and so titanium uptake has been very rapid. But in the marine industry everyone is so used to 316, and it does do a reasonable job, the uptake has been slower. In time I certainly hope to convince everyone to switch over... Particularly those people who are replacing a shackle or pin for the second or third time. Had it been replaced once with titanium, the corrosion would not have occurred. Saving money over the lifetime of the part.

    Take a look at http://www.alliedtitanium.com/products/marine/shackles/vupdc_Detail.php?UPDCID=28379003 for our current shackle offerings. Though we have the ability to add a new size to the list in about a week if there is interest in one.
     
  3. rasorinc
    Joined: Nov 2007
    Posts: 1,853
    Likes: 71, Points: 48, Legacy Rep: 896
    Location: OREGON

    rasorinc Senior Member

    Greg, I sent you a private e-mail. I would not compare your costs to stainless steel. I would compare them to silicon bronze as both are not destroyed by salt water. Your products will be lighter and stronger than bronze and may even be cheaper. I just think it is a better comparison to use (especially in sales ). Does your company make standard size channel? Thanks, Stan
     
  4. Angélique
    Joined: Feb 2009
    Posts: 3,003
    Likes: 336, Points: 83, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    Can't Ti and SS shackles be forged ? I thought that would make them stronger as most metals will be stronger by forcing the crystal structure in a different then the natural pattern . . ? ?

    Good luck !
    Angel
     
  5. Angélique
    Joined: Feb 2009
    Posts: 3,003
    Likes: 336, Points: 83, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    BTW, when I bought a Buck Nobleman 0327TTS-B I was ripped off since I was told in the store it was a titanium knife and I bought it in titanium for light weight reasons in the first place. I doubted about the weight in the store already but blamed it on a "bad weight judgement day" from my side and trusted the store personnel as the packing wasn't clear about it.

    But the weight kept bothering me, so at home I took a magnet at it and it turned out to be magnetic and when I looked up the specs on the web I saw it's titanium coated stainless steel for added corrosion resistance, and for the looks I guess . . :rolleyes:

    By then I was 300 km away from the store and gave away the knife.

    Cheers,
    Angel
     
  6. Stumble
    Joined: Oct 2008
    Posts: 1,913
    Likes: 73, Points: 48, Legacy Rep: 739
    Location: New Orleans

    Stumble Senior Member

    Angel,

    Both metals can be forged, but it increases the cost as compared to casting. Typically it is less expensive to go up in size to a larger shackle than pay for a forged as opposed to cast one. In applications where the size is critical, like in anchor shackles it might be worth it to go to forged parts, but since a cast titanium part is actually stronger than a 316 forged shackle of the same size it becomes hard to justify again.

    In applications where absolute strength is important, well for now we just don't have enough orders of those parts to justify paying for the machinery to forge pieces. Though we are investigating it to see how it might be incorporated.

    Generally think of it like this... Start with a reasonably equipped machine shop

    To machine a part you don't have to spend any additional money
    To cast a part takes $10,000 in additional equipment
    To forge a part takes $500,000 in additional equipment.

    If you are making 5 parts a year dividing that even by the $10,000 cost to cast is likely unjustified.
    When you are making 500 it's not so bad, but the 500k for forging parts is unreachable
    When you are making 50,000 the $500k is easy to justify.
     
  7. Stumble
    Joined: Oct 2008
    Posts: 1,913
    Likes: 73, Points: 48, Legacy Rep: 739
    Location: New Orleans

    Stumble Senior Member

    Stan,

    I used 316 since it is what most people are familure with, and have a thought in their head of what a part would cost in it. While siliconized bronze is certainly a better corrosion material than 316 it is so rarely used in the marine environment that many people don't have experience dealing with it, and have no basis for comparison.

    I am not sure what you mean by channel? But we do deal in most mill products. I would have to check if you are looking for something specific.
     
  8. pdwiley
    Joined: Jun 2008
    Posts: 1,004
    Likes: 86, Points: 48, Legacy Rep: 933
    Location: Hobart

    pdwiley Senior Member

    Do your Ti shackles come stamped with a SWL?

    Reason I ask is, most s/steel ones don't seem to. I can buy a galvanised shackle for ~$3 that has a certified SWL or I can pay 3X as much for a s/steel one with no SWL. Sadly, yachties buy the s/steel one because it's nice and shiny.

    When I was in charge of a marine science R&D group, we had an inviolate rule. Every bit of equipment *had* to be certified with a SWL or it didn't come aboard ship. We would have used Ti shackles if we could have; when you've got the best part of $500K in scientific equipment on a wire, the cost of the shackle is kind of irrelevant and when you're measuring some stuff at the parts per billion level, contamination becomes a real issue.

    Currently for my own personal use, I just use tested galvanised shackles; I'd consider Ti ones for masthead fittings etc but ONLY if they had a stamped SWL, or came with a certificate stating what their tested SWL was. Otherwise, I wouldn't have them on board.

    PDW
     
  9. Stumble
    Joined: Oct 2008
    Posts: 1,913
    Likes: 73, Points: 48, Legacy Rep: 739
    Location: New Orleans

    Stumble Senior Member

    PDW,

    We don't currently test them since most of our sales are to distributors/users that either test or don't according to their choice. But we have the capability to test in house to some degree, for very high loads we would have to shop it out to a testing center. It would really depend on the part, and the test that was requested. A strait line pull on a shackle is one thing, torquing them in strange ways would be a little harder.

    We have been discussing proofing some of them for strait line pulls, but as of yet haven't started doing this without a customers request.

    Part of the issue, is that we are a manufacturer, not a design company, and the company is loath to start making claims about working load or breaking strength, since that significantly increases the potential liability.
     
  10. souljour2000
    Joined: Aug 2009
    Posts: 481
    Likes: 15, Points: 18, Legacy Rep: 195
    Location: SW Florida

    souljour2000 Senior Member

    I'll answer your question from the Bronze thread here Greg. You asked if there was anything else that I might need since you guys already have chainplated,tangs,nuts,bolts,etc....Okay, what about wire rope for halyeard,,could you extrude and twist Titatium into wire-rope...? Afterall..it would be worth it if wire rope halyards lasted twice as long as steel...
     
  11. Stumble
    Joined: Oct 2008
    Posts: 1,913
    Likes: 73, Points: 48, Legacy Rep: 739
    Location: New Orleans

    Stumble Senior Member

    Soul,

    We can get it. But I wouldn't recommend it to you. If you need small diamater halyards, go get Dyneema.

    The problem would be that you would still be stuck using stainless Norseman fittings since those are patented, and we can't duplicate them. So you would have large mass wire, on small mass fittings... That is a crevice corrosion nightmare.
     
  12. TeddyDiver
    Joined: Dec 2007
    Posts: 2,614
    Likes: 136, Points: 73, Legacy Rep: 1650
    Location: Finland/Norway

    TeddyDiver Gollywobbler

    Or use old fashioned roping (throath seizing) and deadeyes..
     
  13. thudpucker
    Joined: Jul 2007
    Posts: 880
    Likes: 31, Points: 0, Legacy Rep: 453
    Location: Al.

    thudpucker Senior Member

    At Boeing I put Titanium Rivets in the Wings of 707's and KC-135's.
    Certain places only. The rest were (or seemed to be) Aluminum.

    I met a Salesman with Sheffield Steel selling to Boeing.

    The Salesman is the real Hero of the Capitalistic Republic of America!
    After a sale is made, everybody goes to work!

    I hope you do well.
     
    1 person likes this.
  14. Stumble
    Joined: Oct 2008
    Posts: 1,913
    Likes: 73, Points: 48, Legacy Rep: 739
    Location: New Orleans

    Stumble Senior Member


  15. Angélique
    Joined: Feb 2009
    Posts: 3,003
    Likes: 336, Points: 83, Legacy Rep: 1632
    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.