Composite stays are the big thing with multihull sailors but when I
checked it out for monohulls it seems that stretch will be a problem.
High tech line seems to be strong enough but it evidently still
stretches more than stainless wire.

Tom Dacon wrote:

This doesn't address your antenna question specifically, but I have to say
that the idea of replacing a stainless wire backstay with rope just creeps
me out. Sure Kevlar, in the appropriate size, could be stronger and still
lighter than the wire, but its long-term durability raises some significant
questions. The lifetime of stainless steel 1x19 and rod is well understood,
as is the response to shock loading; I doubt that the same could be said for
Kevlar. Your backstay's a pretty important rigging component - I wouldn't be
inclined to screw around with it. You might also consider the long-term cost
of more frequent replacement of the Kevlar, versus the cost of the wire and
insulators for about a twenty-year lifetime expectancy of the SS wire and
insulator combination.

I'm not against Kevlar in standing rigging per se, although I'd be inclined
to use it in a "supporting role", so to speak. In fact, I'm thinking of
replacing my 7x19 SS wire running backstays on my 41' 3/4-rigged sloop with
Kevlar the next time I re-rig, not so much to save weight as to keep down
the chafing on my spreaders when the running backstays are housed at the
after shrouds. I just wouldn't use in in a single-point-of-failure
application such as the backstay.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com