I have a pre-onestring winder, which over the years has become slightly 'rougher' in the shroud and lowers control lines. I put this down to the blocks in the system, as some of them are looking a little grotty. These blocks are not to easy to replace, as they tend to be spliced into the wire rope sections that run on up between gunwale and kingpost foot.
Rather than have these remade, and given the ease of splicing d12, i am thinking about replacing the wire sections below the gun whale with d12.

However my concern is that i wont ever be able to reproduce the lengths i have at the moment in the wire sections, given stretch of the D12, and that things wont be 'quite right' - anybody done this before?

Don't use D12. V12 on the other hand is suitable for this, but i'd replace on a 12-18 month cycle due to UV degradation. I know it's supposed to be coated against UV, but it doesn't give much warning before it breaks.

Chris - what about Marlow D12 Max - Allspars think it is the mutts nuts and have even used it for shrouds ...

or Holt Ultra line which seems to have a better UV coating?

I really wouldn't trust dyneema on loads like that. Creep will be a major problem, and I just don't see any way around it. I suppose on something where the strop is short, such as the through deck shroud strop you could use D12 because it's working load will take it, but if it creeps 5mm it's a lot of extra rope to pull in the boat and you'll probably run out of travel on the cascades meaning you have to resplice.

With Vectran you put it on the boat and change it after 2 summers. Over the length of a shroud strop the price differance is neither here nor there. Ultra line is very good stuff, I think my kicker is done with it. D12 Max i haven't knowingly used, but if it's nearly or as expensive as V12 then i'd stick with the Vectran.

For lowers i'd only use wire. You know exactly where you stand with it!

Agreed on the lowers. We had D12 on Enchantment and it was a real pain, stretched like a good'un, especially when wet. Keeping the wire on BAU for the lowers and puller, but replaced the main & jib halyards with vectran / ultra line. Then again as we are not (yet) one-string, stretch is less of a problem.

I think the main problem with using dyneema for something like the shroud strop or lowers is actually the splicing. I think you need to splice the strops off the boat so that you effectively lock the loop at either end by passing each end of the line alternately through the middle of the line before pulling the short end into the outer part. The other REALLY REALLY important thing here is to taper the ends. If you don't the line will be 50% weaker at the point the line ends inside the outer. Once they are spliced I think the splice settles slightly once tension is applied. Once this initial settling is done they will not appear to stretch again. If used for the main halyard though dyneema will shrink in the sun light!!!

I'm not familiar with D12 Max but assume it's an SK78 line as opposed to the normal SK75 D12. I believe it doesn't creep as much as SK75 making it more like Vectran only stronger!

Regards
Tony

Whats being used here then?

the lowers look like wire to me!

But these lowers on 3683 are definitely not wire.

For clarification, it was not the lowers themselves, but the purchases that run from the foot of the kingpost, up to the wire lowers. It is this section i wish to replace, and short of removing them completly and having somewhere make up the sections like for like, i was wandering about replacing them, as 'String' points out, simular to Monkey Business.

Dave

Can you email me please