Wire - Boat Hardware & Rigging
Most of the wire we see advertised today is sold under one specific name leading one to believe the name is the wire manufacturer when really it's the name of a wire broker / importer.
Lewmar - Rodes and Chain | Anchoring & Docking
Standing rigging and Wire
Price is not the best reason to buy wire. The difference between really good wire and marginal wire for a full rig on a 35' sloop is often $60 based on comparison with the wire competitors.
Even a reliable wire broker will fill orders with wire from different mills and twisters if they cant get the product they need. What really counts is who actually makes the wire (twisting or forming) and who makes the wire strands (makes the metal and draws the strand).
Usually these are two different companies. You can buy wire based on the mill and twister,not the broker or price. You must know the equipment and processes these companies use.
Every master reel has a sample literally pull tested to destruction and chemically analyzed then tracked through the system. Strengths on wire chart are minimum breaking
strengths and not the actual; so far they've always been significantly higher.
Swage vs. Mechanical Wire Terminals
Swaging is the process of pushing the metal of the fitting into the gaps between the strands of the wire and flattening the strands just a bit to lock them in.
Most mechanical fittings expand the wire after you pass the wire through a smaller hole (what we call the nut fitting) of the terminal and add compression to the expanded strands via a cone or wedge to keep them from pulling out; you cant pull something bigger through the hole Both types of terminals have advantages and disadvantages.
Swaging: must be done professionally, less room for rust expansion so will "crack"
the shank quicker. Lengths must be accurate when ordering. More prone to fatigue as the "hard" spot is just inside of the swage shank.
Mechanicals: fittings cost more especially if you're paying someone else to put
them on. Larger diameter of the actual fitting may limit where they can be used
. Subject to over tightening and occasional thread gauling. Off brand fittings dont have a 'track record" and may have problems with parts availability.
Generally speaking we like to see boats that are in the southern latitudes use
mechanicals on the lower ends as that's where the water is draining to. Upper
ends dont appear to matter that much. Northern boats generally fair well with
either swage or mechanicals.
Swaging: fittings are generally less expensve even when you include the cost of
the labor to install. Most spars are mfg. with these in mind; you may find pin sizes
(especially on forks) and mounting space is to limiting for mechanical terminals.
Initial strength is 100% of the wire.
Mechanicals: more space inside cavity and uses sealant in most cases to slow rust down and allows for rust expansion (won't blow up as fast). Initial "hard" spot in fitting, where the wire makes a bend or is compressed, is farther inside the fitting lessening fatigue on the wire. Can be installed in the field by any handy person, and allows one to cut the wire to apfxopriate length while it's hanging on the mast to insure accurate fit. Most are re-usable.
1x19 wire is used for standing rigging on most boats. Theise (on photo below) 1x19 wire is type 316 stainless and is strand polished (smoother the wire the more corrosion resistant).
These sheets provide us with a chemical analysis and actual pull break strength of that spool. The wire is only 5-6% less than a type 304.
Strengths listed below are minmum industry standards.
When Do you need to...
You must inspect your rig at least once every season. Cable assemblies generally fail from corrosion or fatigue. Always look for the obvious and look for cracking in the terminals, distortion or pitting in the wire or terminals, and in any of the associated
fittings. Be sure and check spreader ends.
Make sure every thing leads fair. Fatigue is something you basically have to guess at. There is a correlation between fatigue, wire diameter and weight assuming all things lead fair and are properly toggled.
You can start seeing fatigue breaks in the 15 to 20 year range, not a huge number
but significant enough to raise a flag.
The problem with fatigue
is you cant check for it; the wire breaks inside of the fitting. Fatigue is induced by loading (tension) but is more prone to transverse cycles. In other words how hard a boat is or isn't sailed is not as significant as one might suspect. A rig left in a
boat where there is significant movement (air or water) or poorly tuned may actually be subject to more cycles over time than a boat racing around the buoys a dozen or so times a year.
How to Changing Wire Size
Learn at https://groups.yahoo.com/neo/groups/Triton/conversations/messages/11533
the type of fitting
Determine the type of fitting (eye, fork, stem ball, or T-ball) If you have one stem balls or T-balls. Determine clevis pin diameter than enter our product charts and match the clevis in diameter to the wire size desired. Note that mechanical fittings often have different pin diameters or wider selection of pin diameters per type and size of fitting than swage fittings do.