Would aluminium 6060-T6 tubes be ok for Jonquette's battens? (25m2 sail)

  • 24 Jun 2014 22:04
    Reply # 3028409 on 3020736
    Deleted user
    Ok no problem Arne, also your top-down numbering convention makes sense according to your design method. So I will use 40mm x 3 on the first sheeted batten on top. Thank you all for your help.
    Last modified: 24 Jun 2014 22:11 | Deleted user
  • 24 Jun 2014 21:41
    Reply # 3028386 on 3020736
    Anonymous member (Administrator)

    It is I who by error started to count the battens and panels from top. Now I find it logical to use it on my sails, so I can't stop: The top section will always be panel 1 - 3 and the transition panel will always be panel 3, regardless of if the sail has 6, 7 or 8 panels. 
    Sorry for the confusion I have made...


  • 24 Jun 2014 19:59
    Reply # 3028252 on 3020736
    Deleted user
    Oh but I was counting from down to top. I thought this was the convention for panels and batten. In my edition of PJR, they are numbered that way. So from what I understood, batten #2 was the second one after the boom. But in fact, it is the second one after the yard, right?
    Last modified: 24 Jun 2014 20:32 | Deleted user
  • 24 Jun 2014 19:42
    Reply # 3028223 on 3020736

    Batten 2 and it's sheetlet controls the top two panels, so you've got double the sail area and forces on that batten with respect to the other battens. I'm not sure why PJR doesn't have this issue covered, perhaps all their battens are higher strength. Over his design process Arne started with lighter battens and increased them as necessary. I'm sure Arne can address this in more detail.  

  • 24 Jun 2014 19:14
    Reply # 3028179 on 3020736
    Deleted user

    Yes, of course, I want to use your rig design! Just for my personal culture, why is it better to have a stronger tube for batten #2? In "Practical Junk Rig", it is stated that "The loads on the sheeted battens decrease steadily from the uppermost to the lowest", so I thought that upper battens had to be the strongest.


    Last modified: 24 Jun 2014 19:22 | Deleted user
  • 24 Jun 2014 11:28
    Reply # 3025645 on 3020736
    Anonymous member (Administrator)

    If my calculations are right,  then the 40 x 1.5mm tube is 4% stronger than the 35mm tube. I also guess that it is stiffer, although I haven't worked out the inertia of the sections.

    For the batten no 2, from top  (if you use my design) I would double the strength, to 40 x 3mm .


    Good luck,


    Last modified: 25 Jun 2014 07:24 | Anonymous member (Administrator)
  • 24 Jun 2014 07:49
    Reply # 3025430 on 3020736
    Deleted user
    Hello David,

    Thank's a lot for your answer. Closest they have is either 35mm x 2mm (0.56 kg/m) or 40mm x 1.5mm (0.49 kg/m). My intuition would suggest using 40 x 1.5, but may be could you confirm that choice?



  • 23 Jun 2014 22:17
    Reply # 3024590 on 3020736

    6060T6 is OK. I'd choose 1 1/2" diameter x 1 1/16" wall, 38mm diameter x 1.6mm wall for a 4 metre batten.

  • 23 Jun 2014 11:51
    Message # 3020736
    Deleted user
    Hi all,

    I found a provider for 6082 aluminium tubes for my mast, close from home, and Arne helped me select the correct products based on strengh requirement & availability (thanks again Arne!).

    Now, decisions need to be taken for battens... According to FAQ "battens" topic, aluminum tubes should be 6061 or 6063 T8. Provider has a large choice of tubes between 20 and 45mm (and more), thickness 1.5 to 5mm, but only 6060 T6.

    Would that still be OK? Also, any recommandation for diameter/thickness that would be good for my 25m2 sail? (small boat, ocean crossing program, sometimes bad weather)

    (PS: Here is Jonquette's rig conversion document from Arne's page Jeanneau 6.6m )

    Thanks in advance for helping!

       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
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