Airex/Divinycell question

Discussion in 'Fiberglass and Composite Boat Building' started by charlyIII, Oct 18, 2012.

  1. charlyIII
    Joined: Oct 2012
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    charlyIII Junior Member

    Hey guys,

    My composite chainplate drawing specs Aiex R90.300 for the core

    I have a source for Divinycell, and the seller calls it 14-60.

    I have no experience with either product. Are they compatable density? Am I asking the right question?

    THanks
     
  2. Charly
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    Charly Senior Member

    Heck. Maybe I should start over.

    Ok nevermind the divinycell. The plans call for Airex R-90.300, and R90.200. what do these numbers mean? Are these products still available? (I thought Airex was discontinued) What would be a comparable product?
     
  3. DGreenwood
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    DGreenwood Senior Member

    As I recall the R90 is a crosslinked foam with better test scores than the earlier non cross linked foams. The 300 and 200 refer to the density which would be approx. 300 kilos per cubic meter. I think they are still available but I am a little out of touch these days. Any good composites supplier can help you find a comparable if not available.
     
  4. tunnels

    tunnels Previous Member

    http://www.atlcomposites.com.au/atl_composites2/products/cores/airex__foam

    You want information go directly to the source !! airex is alive and well :confused:
    My views on foams is if in doubt use a denser foam never a softer one! never !!!
     
  5. DGreenwood
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    DGreenwood Senior Member

    My advice is to use what the designer tells you to use.
     
  6. Boatlands
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    Boatlands New Member

    hi Charly, As DGreenwood pointed out 300 refers to density of the foam with kg/m3 unit. It is a high density foam. DIAB has a foam called HCP70 with density of 300kg/m3. please have a look at the attached files. let me know if you have any other questions.
    Any views or opinions presented in this message are solely those of the author and may not necessarily reflect the opinion of DIAB or its affiliates.
     

    Attached Files:

  7. Charly
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    Charly Senior Member

    Thanks for all the replys!. It turns out, after speaking with the designer, I don't actually need any core for the chainplate layup. The composite chainplate plans I have are for an airex cored hull, but since I am building in plywood anyway...I can just use a plywood core:eek:

    So now I feel like a real dumba$$:D Thanks for putting up with me. And at least I did learn something
     
  8. DGreenwood
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    DGreenwood Senior Member

    Reading and trying to follow plans carefully, then calling the designer to clarify, certainly does not make you a "dumba##". The designer probably overlooked that notation when he adapted the plans.
     
  9. tunnels

    tunnels Previous Member

    If you using ply and glassing each side then think seriously of laying some unidirectional under the glass skins both sides where there will be lots of pull !!
    uni is glass running in one direction and a excellent way to distribute loads over a bigger wider area so if something is going to break its not going the be the Chain plate landing
    In racing yachts we use two layers of 800 gram 300mm wide each side if the foam core going from Gunnel to Gunnel and two more going from stem to stern down each side of the where the keel stub was located :D
     
  10. Charly
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    Charly Senior Member

    The plans have an elaborate layup schedule with varying lengths and widths of uni with some biax interspersed.

    Where the chain plate is proud of the deck is where I was concerned about. I already have the hull and deck built, in ply and balsa, with stringers and ply doublers in place inside the hull. Instead of airex, or any foam type core, I can simply use ply as a core for somethng to mount the pin on, proud of the deck, and at the proper angle to accept the shroud turnbuckle, Then, weave the fabric over core and pin, and back down through a cut-out slot into the inside of the hull to layup on the chainplate doubler and the adjacent bulkhead.

    I had toyed with the idea of bagging the layup to the hull on each side, with two vac setups, going at the same time. I think Murphy might be likely to show up if I do try that, though.;)
     
  11. tunnels

    tunnels Previous Member

    ONE THING ABOUT CHAIN PLATES IS THEY SHOUD BE STRONG ENOUGH TO BE ABLE TO LIFT THE BOAT FROM WITHOUT ANY DOUBT !!!! THE 36 FOOTER I WAS PROJECT MANAGER FOR WE DID JUST THAT . FULLY COMPLETED WE LIFTED OFF THE CHAIN PLATES !! WITHOUT A PROBLEM
     
  12. Herman
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    Herman Senior Member

    The only thing I would like to add is that, although I am an Airex distributor, I am not aware of the R90 variation (at least not in Europe) but I suspect it must be the T90 spec, which has been available in 240 and 320 kg/m3. Unfortunately these have been abandoned, and replaced for T90.210 (210 kg/m3, with same strength as previous T90.240). There is no replacement for T90.320, except for PXc foam (Coosaboard style) which is not available in small quantities, so basicly useless for DIY builders.

    Can you ask the designer to check from his end?
     
  13. Charly
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    Charly Senior Member

    Herman, these plans were drawn originally for an Airex cored hull catamaran build, that is several years old (2001). The designer passed them along to me to fulfill my request for a layup schedule for the chainplates on my similar sized cat.
     

  14. Herman
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    Herman Senior Member

    OK, at that time the T90.320 probably did exist. I guess now C70.250 does the same job.
     
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