A Photo & Discussion Forum for Wharram Design Enthusiasts
We put the amst up, and tried to tighten the rig.
We use, for everything, shrouds, forestay and bridle, Samson AmSteel Blue, 3/16", and I made splice on 50 cm lenght, which should be enough.
For the shrouds, as on the booklet, we used 6mm polyester, 4 full turns, to tie on the hull. For the forestay, we take a turbuckle, and that was tight at first.
After we tried to hoist the sail, we noticed tha everything went loose.
I plan to unsplice the forestay, and redo it shorter. Can I use the same rope, or do i have to use a new one? Also, if I use the one in place, will it streched again? That material is supposed to have n extremely low strech.
I have no experience with Dyneema standing rigging. However, I have done a lot of research while planning my own new rigging and found that many people struggle to maintain rig tension because of "creep" in new dyneema. It put me off and I have decided to stick with 7X7.
Maybe the best decision! I liked the idea, found that Wharram used it on his own boat. But after two and half year of building, I didn't need another chalenge.
I like your website by the way, have fun with yourboat,
Making splices in dyneema introduces slack when you open up the line. The standard procedure is to account for that in your measurements and then stretch the lines after splicing.
For example, I used 6mm dyneema for my dolphin stay. I spliced each end with 18 inch tail bury. I measured so that the stay was actually 4 inches (two inches for each splice) shorter than needed. And then stretched the stay using a come-along. It did indeed stretch 4 inches back to the specified length. But even with a lot of pressure it would not stretch beyond that. I'll attach a pic of stretching that dolphin stay. It took a few hours of applying pressure and letting it sit and then coming back and applying more pressure.
I think you probably need to stretch your lines after splicing and before putting on the boat.
Hope that helps,