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Forestay -n- shroud adjustment help
Posted: Sun Apr 03, 2005 7:56 pm
by argonaut
Finally got a chance to run up the sails and check the rigging today. Dang close to splashing.
The rig was really strangely adjusted by the PO.
Everything was so tight as purchased (used) that I couldn't get the mast beyond about a 98 degree aft rake angle w/respect to the deck. The furler was a devil to pin and took heroic two-man efort.
Problem is there still seems be way too much aft rake. It's way more than the 6 degrees the manual describes.
So... I began making adjustments.
I loosed the backstay completely, then loosened the shrouds. (PO had inserted one turnbuckle which I put back to factory adjusters.
Now, with my backstay totally loose.
The uppers adjusters are as long as they'll go, there are no holes left to use in them. The clevis pin pins together the tang and the adjuster thru their end holes.
For the lowers there are four empty holes on the tangs, the pins go through the second set of holes from the top.
Adjusted this way there are inches of slop left in the forestay.
It's like my forestay is way long, and the upper/lower shrouds are really short.
Is anyone else's shrouds adjusted this long?
I read "tuning fractional rigs" though nothing there helped my problem of excessive rake.
Could my forestay just really be too long and my shrouds too short?
Posted: Sun Apr 03, 2005 8:28 pm
by Moe
Do you have roller furling? If so, have you pulled the pin out of the drum, and slid it up the foil to expose the forestay turnbuckle and adjusted it tighter?
--
Moe
Posted: Sun Apr 03, 2005 8:54 pm
by Murv Barry
I had the same problem with the upper shrouds being too short and the forestay too long. Resolved the shroud length by adding tangs to each. Raised the hound up the mast about 6 inches to resolve the forestay problem. Did this 4 years ago when I first bought my boat and it has worked fine. My headsails are hanked on....Murv
Posted: Sun Apr 03, 2005 8:56 pm
by Frank C
Forestay and upper shrouds are a matched set, and must be coordinated legs of a pyramid. In order to revise rake to 2 degrees aft, I had a new forestay made-up at 4 inches shorter than factory. This left the shrouds almost too short, adjusted in the final vernier holes. The lesson is that a minor difference in length is significant.
Turnbuckles make it obvious that he was tweaking the rig. He may have shortened the uppers, making it impossible for you to swap the turnbuckles back to verniers. How do the verniers and his turnbuckles compare in length?
* Maybe there are spare wires of differing lengths in a bilge?
* Is the forestay connecting AT the upper shrouds?
* Are there various sets of holes drilled in the upper mast? Maybe he tweaked things there too.
The answer's there, but you might need Sherlock to help deduce it. Good luck!

Posted: Sun Apr 03, 2005 9:59 pm
by argonaut
Moe, yes I pulled the drum and shortened the forestay as much as was possible with the forestay turnbuckle. It's cranked all the way short and there's still tons of slack. I could pin the thing about six inches forward of the existing forstay tang. (Maybe a good chance to construct a tensioning lever.)
The PO had added a turnbuckle starboard, and on the backstay but he left the adjuster tangs intact, hanging on the nicopress fittings, and just pinned the turnbuckle forks thru the existing shroud eye fittings. Elegant...
But from the looks of it I'd need like another 3-4 inches of shroud length each side uppers and lowers, and like a 4-5" shorter forstay to be able to bring the mast a few degrees aft rake of vertical.
The lower mast that is. The backstay's totally loose yet.
Is the aluminum hatch track supposed to be a level surface? I had a 4 foot level laid on that track dead level, and my mast was 4" off-plumb over it's 48" length.
The PO was definitely tweeking Frank. I didn't find any wires below but did find a Loos gauge. Hmm, a bad sign.
Even the STBD turnbuckle I got rid of was nearly cranked the entire way long. BTW, it was a closed body model. Nothing keeps them from being turned completely apart, I discovered! Now I understand why open turnbuckles are a good thing.
Frank when you say matched set, you don't mean all three the same length, right? Just the 2 uppers and the 2 lowers?
Or are they really 3 (uppers and forestay) matched-length wires with the spreaders making up the base angle difference?
Maybe I could get longer adjuster bodies & leave the shroud tangs intact.
Posted: Sun Apr 03, 2005 10:34 pm
by Frank C
Sorry - I meant the forestay & uppers are a matched triplet to position the mast, but not identical lengths (don't have a clue what the actual lengths are). Considering her past, examine all nico fittings & wires closely for corrosion or cracks. Is it time to upgrade?
Maybe Dealer-Bill has a factory blurb stating the correct length of shrouds & stays. In fact, maybe Bill could fix you up with a factory set (but that puts the rig at 4 degrees aft). My local rigger charged $50 for a new forestay, swaged fittings. As I said before, exactly 4 inches shorter changed rake by exactly 2 degrees (was 4*aft, now 2*aft) measured w/ digital level. It also pulled the shrouds out to the final adjusting holes.
Properly tuned, the rig demands gonzo effort to pin against just the shrouds - with backstay limp. You should just shorten the backstay by 6 feet and add a splitting tackle down to both aft quarters. Search on "adjustable backstay" for more info.
Posted: Sun Apr 03, 2005 11:59 pm
by argonaut
Yes I can also find them from BWY, but same deal, they'd be factory length and if that's what I already have, no gain.
The forestay I could shorten with a new set of holes.
I do plan to do Duane's backsty mod, it's a bit simpler and the split rig looked like it would snag on the hinged seat.
Posted: Mon Apr 04, 2005 1:03 am
by craiglaforce
Couple of short responses. don't mean to be harsh or blunt, but just efficient, since it is late.
1) Yes, the rig needs to be quite tight. Just the way it is if you don't want the rig to pump in wave action and come down prematurely. the forces that the rig is exposed to are high and the restraining forces also need to be high.
2) changing mast rake is only to be done to correct helm balance. Not 'cause it looks funny. You say you haven't splashed the boat yet but are changing the rake that someone obviously took time and effort to set with some experience sailing the boat. Mistake.
3) closed body turnbuckles ussually have a small pinhole in them to keep them from unwinding. There is supposed to be a little stiff wire spring clip ot something that goes in the hole.
4) I prefer the turnbuckles over the vernier adjusters. They let you adjust rig tension while the rig is up.
Not trying to be rude, just trying to offer some advice in a quick manner that might help you.
Just my opinon.
Posted: Mon Apr 04, 2005 4:28 am
by Catigale
I prefer the turnbuckles over the vernier adjusters. They let you adjust rig tension while the rig is up
Turnbuckles are a more sophisticated way of tuning with finer control, but they are more susceptible to subtle twisting/bending damage in contrast to the KISS vernier chainplates that come on the Mac.
On a trailer boat, with a lot of mast up-and-down, the rationale for chainplates is that they aren't so easily damaged.
Of course, if someone wanted to argue that chainplates are cheaper, ergo their use, I couldnt argue that point...
Best solution (without regard for cost) - turnbuckles with careful inspection protocol, perhaps.

No Hudson sailing this week, despite winter having broke. The Waterford Sail Center is underwater this morning due to flood levels!!
Posted: Mon Apr 04, 2005 8:01 am
by argonaut
No offense taken. I appreciate all comments and we all learn, yadda yadda.
No I don't know how the helm handles under sail yet, but after finding 7 missing ringdings and several hardwarestore bolt & nuts used I got the impression the PO never heard of Brion Toss & figured it might be a good idea to follow the manual's setup instructions, to know how, if nothing else.
The PO had also screwed both sets of verniers together with plastic cleats, kinked two shrouds, twisted the spreaders and had left all of the turnbuckles unpinned, including both on the forestay. So I stripped it back to all the factory rigging and filled in all the missing rings.
But like I said, the shroud verniers are all the way out (loose) now, tightening them will also lengthen the forestay which already is too long to pin by about 4-6 inches.
Irregardless what the exact rake ends up being, just fastening together the factory hardware makes the forestay too long.
The turnbuckles would probably be a good thing, especially with rings in.
Posted: Wed Apr 06, 2005 6:48 am
by argonaut
Hey thanks Moe... pretty good for one cup.
I can confirm that the backstay isn't long enough... My PO added about 11" of turnbuckle to the backstay,( 15" from the nicopress eye to the center of the fastening hole.) Otherwise I'd never have been able to get the mast as far forward as I did.
I did the trig stuff with the level, but the forestay is too short to fasten the mast as far forward as it will go.
The upper vernier has 4.5" of adjustment but at the wide open setting the forestay is far too long. I think the forestay only allows about 3" of adjustment range, which isn't gonna let the mask move much.
Hmmmm. I haven't drilled any holes in the mast yet...