Nigel wrote:
"Howard" wrote in message
ervers.com...

Something to ponder while watching the snow.

I have a 20 year old steel cutter with original wire rigging. Ted Brewer
design.

The orignal owner fitted it out with all 1/4" 316 standing rigging.

I'm thinking of changing out part of the rigging, the back stay and fore
stay. It all looks good but just because.............

Anyway two questions:

1. Supposed I change out the wire, these are the two longest, and then
save the used wire as emergency wire. The wire fails at the bottom
connection so wack off 6" and the rest is good! No? New bottles etc. of
course.

The wire fails at the bottom for a couple of reasons. One, when using
compression fittings, the metal hardens from compression (i.e. work
hardening) reducing ductibility at the wire/fitting interface which
makes this area more succeptible to cracks. And two, from corrosion due
to salt water wicking into the fittings and pitting the wire -
especially true when any micro-cracks are present presenting a
less-passive surface. 316 s/s is about 20 times more resistant to salt
pitting and corrosion than 304, and thus will last significantly longer
under sea spray conditions.

2. Ted Brewer recently wrote in Good Old Boat about standing rigging and
is apparently partial to 304 vs 316. That does not seem to be
conventional wisdom, yet consider the source. So what say you, 304 does
have more strength for the same weight and windage. What are the
detractors and how severe?

304 has slightly more tensile strength (5-10%), *for any given level of
cold worked temper* than does 316. However, you need to make sure you're
comparing apples to apples, since the tensile strength of each will
double for fully hard temper vs 1/4 hard temper (ASTM A 666, Standard
Specification for Austenitic Stainless Steel, Sheet, Strip, Plate & Flat
Bar). So fully hardened 1/4" 316 wire has almost twice the tensile
strength of 1/4 hardened 1/4" 304 wire. Thus you need to make sure of
the temper when you're comparing the two (or purchasing).

Whether the longevity of 316 will pay for the additional cost, in your
situation, I don't know. IMO, if you sail often, and sail hard, use 304
and replace more often. If you spend more time in the bay, or marina,
use 316 and replace less often.

Keith Hughes