Do you think that reinforcing with a Dyneema whipping (or similar) would work? Then it would not matter much which material you used.

The reinforced aluminium tubes I have seen had slightly larger tubes epoxied over the ends. The main problem would be sourcing the matching tube, otherwise that does not seem very complicated.

Is the reason you can't reinforce aluminium with GRP poor adhesion?

Michael Moore wrote:

David Tyler wrote:

I recommend GRP tube from https://www.carbonfibreprofiles.com/ as it's easier to reinforce the end at the joint. 38 x 34 for Weaverbird, 30 x 27 for smaller boats.

Just one question David. Why do you choose grp over aluminium? I'm just wondering if the grp will bend and then freeze that bend unless treated with great care

Mike

As I say, reinforcing the end in way of the hinge is vital, and that's more of an engineering job with an alloy tube. With GRP tube, it's a simple wrap of glass and resin. Apart from that, I just find theses GRP tubes easy to work with and easy to live with. They have diagonal fibres in the mix, so don't split. I've been hammering my rig fairly hard at times, this summer, and my sail is bigger than yours, so using the same battens, you have capacity to spare.

I just wanted to thank you all for this thread. By coincidence I was just thinking about how to put articulated battens in my Coromandel Tammy Norie's original sail, without destroying anything or making any irreversible changes. The information here is very handy.

For what it's worth, searching for "acetal rod" on eBay will find a lot of ads for reasonably-priced billets of polyoxymethylene used to make hinges and end-stops. Chris Edwards designed a simple batten end stop which is a plug of this material with a hole drilled through it perpendicular to the batten. Simple and effective!

I am quite tempted by the idea of making all the batten sections the same length (although with different joint angles fore and aft) so that I can carry interchangeable spares.

David Tyler wrote:

What length of batten, Michael? Mine are 3375mm and I found 30 x 27 a bit flexible in hard weather last year, so I upgraded. I recommend nylon 6.6 or aluminium for the double cones - but only nylon if you go for alloy tubes.

Hi David,

The battens are 11ft 10inch, that is 3632mm. They are wood, and 1.5 inch square at the luff, tapering to 1x1.5 aft of the mast. So, 38mm tube?

Mike

David Tyler wrote:

What length of batten, Michael? Mine are 3375mm and I found 30 x 27 a bit flexible in hard weather last year, so I upgraded. I recommend nylon 6.6 or aluminium for the double cones - but only nylon if you go for alloy tubes.

Hi David, I think mine are 3500, but I'll check today. Yes the 30 x 27 looks a bit small and 3mm walls rather thin (?) I like the 38 x 34 if they fit in the pockets. (check today!)

Mike