Why not Spectra ?

[Joe Henderson]

Dear All,

I have no idea how long this tuff will last in standing rigging.

I know that fragile Kevlar lasted around the world on Rothman's runners, checkstays and upper diagonals, so who knows.

I suppose it will be up to us collectively, as a trade, to do the best job we can, try to second guess and pre-empt some of the more obvious failures and pitfalls and then back the work up with vigilant inspections when possible. Pretty much what we have all been trying to do for the past thirty or so years.

I pre-stressed and served more in an attempt to hold the elongation on the runners than any anti chafe measure.

In the end I just used Vectran in it's normal polyester cover.

I do think that service will be a good thing on fibre standing rigging. It's hard-ish exterior should guard against chafe from sheets and will let you know early if something untoward has happened to the stay. I think it is likely that you will see some distortion of the serving which will draw your attention to a potential problem. I also reckon it looks better than a bit of braided cover and it will be easier to keep ratlines in place.

I like the idea of the alloy deadeyes. We made some out of Tuphnol a while ago and they went ok. We made sure that the laminates of linen were aligned across the load paths etc. I imagine the load directions are pretty much the same as in a sheave with the pin taking the place of the lanyard etc. On the smaller stays rig we actually used some Main Marine Tuphnol sheaves and just drilled and scored some new holes for the lanyard, round off the lips of the sheave and it looks like a bought one..

The timber shelled modern block is a great idea and works really well. Lets you have all the fun of varnishing without the pain of friction-plus blocks. Our grandfathers would have used them like a shot if they had been available, same as most things.

Make sure you don't glue the block shut. You do not want to have to break the timber to dismantle and repair the block like I did. Who knew that a bit of Sika could end up costing me so much!

Regards,
Joe Henderson

[Jak Mang]

A few questions on the modern ideas for traditional boats -

Are deadeyes/lanyards used for fore and back stays as well? I don't remember seeing them on traditional boats, but I also have not been looking for that detail. If not, what method is used for adjusting tension?

Anyone have a good source for deadeyes? I'd be interested in bronze or wood.

On a related subject, I saw some nice Lewmar blocks (on Brion's handy billy) that looked like they were made to accept small screws on the outside of the body. Is there any problem using these to attach wooden cheeks? Are you guys making your own cheeks or do you have a source?

Thanks,
-jak

[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?

[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

[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