Whats marine aluminum alloy is better Sealium or Alustar?

Discussion in 'Materials' started by jaboshipyard, Mar 8, 2013.

  1. jaboshipyard
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    jaboshipyard Jan Wierzchowski

    Hello all !

    What you think what aluminium alloy is better Sealium or Alustar for yachts ? Maybe it's not worth their price and better to use standard aluminum 5083 ?

    I will be greatful for your opinions and differences between this materials.

    Best Regards,
    Jan
     
  2. Ad Hoc
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    Ad Hoc Naval Architect

    hello Jan,

    Welcome to the forum.

    It really depends upon the application.

    These improved alloys have better fatigue resistance and also a higher allowable design stress. Which in theory sounds great.

    But when you do your sums and you find that you calculate a value of say 6.2mm for your bottom structure, what would you use, 6.0mm sheet. Whereas if you use 5059 or 5383, the calculation shows 5.8mm, great, but what plate thickness would you use, 6.0mm still!

    But on another boat, you may find that it is subjected to fatigue, more than a standard boat, thus going for the improved fatigue resistance would be of benefit.

    So on smaller boats there is no real gain. But, on larger boats in the say 80m+ size, or if a real need for fatigue improvement, then yes there may be benefit, in terms of the cost is offset by the weight savings.

    Thus, it depends upon the application...and cost v weight savings.
     
  3. jaboshipyard
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    jaboshipyard Jan Wierzchowski

    Hello Ad Hoc,
    Thank You for your quick answer.
    Yes I know taht is depends upon the application. I thinking too use one of this kind improved aluminium on ca 22 meters long sailing yacht. And I whant to get more info. about this materials.

    When you saying that "in terms of the cost is offset by the weight savings" you mean that what I save on weight I will still pay the same for all materials like using standard alloy ?
     
  4. Ad Hoc
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    Ad Hoc Naval Architect

    Well, that's the point, whats the difference? You will have to work out if there is a cost and/or weight benefit. You will only know once you design the structure using 5083 and its cost/weight, and then the same with 5383/5059. Then you'll know.
     

  5. jaboshipyard
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    jaboshipyard Jan Wierzchowski

    Yes that is true I will have to work out :)

    Thanks for your opinion Ad Hoc


    Someone have more opinion and experiences ?
     
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