Why not Spectra ?

[Jak Mang]

Has anyone tried Spectra for bobstays? Is there any data on long term exposure to saltwater?

I'm also interested in tensioning alternatives to deadeyes for this use. Brion mentioned a horror story in a class about turnbuckle below the water line on a bobstay. Obviously, the turnbuckle should have been on the upper end. This lead to a hint that perhaps the turnbuckle could/should be eliminated all together. Is there a way to pre-calculate tension on fixed-length gangs and install them under load? This would save a lot of hardware and weight.

I apologise for the novice questions. I'm trying to immerse myself in the technology.

Thanks,
-jak

[osteoderm]

Jak,

Chafe is a major issue with bobstays. You'll often see chain bobstays where wire would suffice (strength-wise) for just this reason. Anchor rodes, floating debris, docks, dinghies, etc., will all likely be found chafing away at your bobstay at one time or another. For the same reason, i think rod bobstays are a bad idea too; with no resilience, the inevitable impacts are bound to severly stress the metal.

[Ian McColgin]

Side note: Chain bobstays are generally a worse choise than proper cable because chain is far mor subject to electrolytic and oxidation damage, much more stretchy in a bad way, more subject to catastrophic unannounced failure, not significantly more chafe resistant, equally chafe causing, and not enough more immune to deflection or impact damage to offset make other disadvantages.

Any boat with a bowsprit should have a pendent to secure mooring and anchor rodes up through the end of the bowsprit anyway.

G'luck

[Norm Moore]

This is a really informative discussion. It sounds like Technora/Specta would work well for the short rope strops for halyard blocks on a traditional rig. Given the short lengths, creep shouldn't be significant. Spectra also looks like a good choice to replace the wire forestay I planned to use on a Dyarchy type bowsprit rig. Any tips for spliciing Technora/Spectra?

[Brion Toss]

Hello,
Let's see, I'll start with deadeyes. Go to http://precourt.ca/ for a look at the finest aluminum deadeyes you are likely to encounter. Beautiful things. Or try Port Townsend Foundry for some equally exquisite bronze ones. Don't use blocks, as they can't be as strong, and will likely deform in the bearings anyway.
Many traditional boats usedeadeyes or hearts to tension stays, including bobstays (hearts are a sort of open-body deadeye. On the stays, to get the tack of the sail down close to the sprit, mast, or deck, the wire is commonly led through a fairlead, and thence to the deadeyes or hearts.
People use chain bobstays primarily to keep the rode from chafing the bobstay, and this chafe can be completely avoided by leading the snubber to the end of the bowsprit (see the "Apprentice"), which also makes for more efficient anchoring. Putting the stem fitting up at a sane height, and/or installing a sacrificial linkplate at the bottom end precludes chafe from most other sources. Chain is heavy, noisy, and doesn't give enough warning of failure.
As for eliminating turnbuckles, it's usually easy to do on bobstays, as these are never adjusted; just get the length and size right, and it will be tensioned by the jibstay and backstay. I've also dispensed at times with turnbuckles on the jibstay, springstay, triatic, maintopmast stay, and queen stay. It takes careful measuring and fabrication, but the result is a significantly lighter ó and lighter-looking ó stay. Cheaper, too.
Whoa, that's too many disparate topics for one thread. Come on, guys, feel free to start new ones!
Fair leads,
Brion Toss

[Jak Mang]

Originally Posted by Norm Moore

This is a really informative discussion. It sounds like Technora/Specta would work well for the short rope strops for halyard blocks on a traditional rig. Given the short lengths, creep shouldn't be significant. Spectra also looks like a good choice to replace the wire forestay I planned to use on a Dyarchy type bowsprit rig. Any tips for spliciing Technora/Spectra?

There are splicing instructions for a burried Brummel on the Precourt site, in The Apprentice and on Brion's Eye Splice DVD. As a novice, this seems to be one of the easiest eye splices.

The ability to splice this stuff rather than relying on swaging or expensive terminals seems like a major plus for cruisers.

-jak

Check out precourt in canada www.precourt.ca These guys are into racing multhulls and have some interesting ideas.

[Tom Roberts]

Hi,
As a new member I've learned a lot from browsing the site but mostly it makes me realise how little I know.
I'm re rigging a wharram 42 using his gaff rig wingsail. 34 foot alloy cylindrical spars with sleeved sails.
The spars have tangs so I won't be using drop overs but will use deadeyes and lanyards to the chainplates.
I've never worked with spectra but am prepared to practice 'til perfect. Will it do the job for my shrouds? I'm figuring on using ss for the forestay to avoid chafe from hank on sails.
Any advice welcomed and criticisms accepted .Thanks, Tom