Thanks to the list, I am learning more than I probably need to know about high
tech lines!
Anyhow, it seems these lines if properly sized and spliced, etc. can last a
long time and then when replaced, can be done with a competent, relatively easy
splice in such single braid line.
OTOH, a wire cannot be spliced and needs specialized tools to connect it to
eyes, etc. This is usually beyond the DIYer skills/tools.
In the line case, a DIYer can do it and probably will have to over its lifetime.
In the wire case, it takes a professional but the connection will likely
outlast the boat and/or owner. In my case, the single strand check stays look
as good as new after 26 years during which time I did absolutely no maintenance
on them.
While others mileage may vary, I am not sure that in this application much is
gained using line instead of wire over a 20 year+ lifetime--am I missing
something?
Charlie NelsonWater Phantom
-----Original Message-----
From: Steve Thomas via CnC-List <cnc-list@cnc-list.com>
To: Chuck Gilchrest via CnC-List <cnc-list@cnc-list.com>; cnc-list@cnc-list.com
Cc: Steve Thomas <sthom...@bellnet.ca>
Sent: Sat, Jul 24, 2021 1:08 pm
Subject: Stus-List Re: Wire vs. Dyneema check stays
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 ThomasC&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 MagicLF 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
