There are YouTube videos on the splice technigues and there are tables to compare strength of dyneema to stainless rod or wire. I replaced my lifelines w dyneema and now I'm doing the runners, checkstays and jacklines.
I won't argue replacing rod with dyneema. I'm don't have the experience or expertise. I'm impressed by the Volvo 65 and IMOCA 60's which have all synthetic rigging. Chuck > On 07/24/2021 1:08 PM Steve Thomas via CnC-List <cnc-list@cnc-list.com> > wrote: > > > Chuck, > > There are two things unknown to me that make me hesitate when considering > UHMWPE for standing rigging: > > 1. How long can we expect it to last on an "ordinary" sailboat in > "ordinary" use if appropriately sized and properly installed? > > 2. Is there any way to inspect the lines for deterioration or loss of > strength? > > And finally, > > Would you recommend it for replacing the rod rigging that most of us are > still sailing around with on our C&Cs? > > Would such a conversion be likely to wind up more or less expensive for > parts than conventional wire rigging? > > The new fibres and ropes are not so new anymore and I am guessing that > there is enough field experience now that these are not unreasonable > questions. > > Thanks for your helpful contributions to the list knowledge base. > > Steve Thomas > > C&C36 MKI 1980 > > C&C27 MKIII 1978 > > ------ Original Message ------ > From: cnc-list@cnc-list.com > To: cnc-list@cnc-list.com > Cc: csgilchr...@comcast.net > Sent: Saturday, July 24, 2021 9:21 AM > Subject: Stus-List Re: Wire vs. Dyneema check stays > > Full disclosure, I work for a rope company. But a few things so say > regards to Dyneema. First of all Dyneema is a brand name that comes in a wide > range of “models”. The actual material is UHMWPE or Ultra High Molecular > Weight Polyethylene. A Dutch company DSM makes the yarns with subtle > differences in order to achieve different characteristics such as strength > and elongation and something called “creep”. The grades of Dyneema are > categorized by an SK number with the higher numbers yielding higher > performance, generally speaking. However DSM is not the only company that > makes UHMWPE yarns. Honeywell makes an equivalent yarn called Spectra which > also comes in different grades. Finally there are generic offerings, > typically Asian made that are often much cheaper than Spectra or Dyneema but > quality tends to vary. > > > > A rope maker can choose which yarns to use in a > particular rope, using the fibers to make either a 12 strand hollow braid or > to use the high modulus fibers as the core in a low stretch double braid with > an outer cover braid of a high wear or YV stable material like polyester. > Doing the latter adds weight, but dramatically increases longevity. Even if > UHMWPE is used just for the core, most companies will still coat the yarns in > a urethane bath to provide additional protection from chafe and to provide > color coding. > > Finally, some rope makers will use a process called heat setting > > the Dyneema rope by pre-stretching and aligning the fibers and then > > exposing the rope to a heat process that removes most of the creep (non > > recoverable elongation on a molecular level). There’s usually a slight > > reduction in overall strength with heat set ropes, but far less stretch. > > It is these heat set ropes that I would recommend for any standing > > rigging application. UHMWPE is quite slippery and achieving proper tension > > and maintaining it under load can be challenging without the proper > > terminations and fittings. > > Several companies like Colligio and Blue Wave offer specific > > hardware to create standing rigging solutions that provide adjustments and > > tensioning solutions. > > Hope this helps.. > > Chuck Gilchrest > > S/V Half Magic > > LF 35 > > > > > Thanks to all of the subscribers that contributed to the list to help > > with the costs involved. If you want to show your support to the list - use > > PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu >
Thanks to all of the subscribers that contributed to the list to help with the costs involved. If you want to show your support to the list - use PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu
