The mystery of rig tuning

Oct 19, 2017
7,732
O'Day 19 Littleton, NH
You may need to think about cutting back on that. After all, I wouldn't expect you to cut back on your sail time.

And where were you for the exciting "Wow" thread? Definitely a vacuum there without your input.

-Will (Dragonfly)
 

TomY

Alden Forum Moderator
Jun 22, 2004
2,758
Alden 38' Challenger yawl Rockport Harbor
I have a simple old boat. Drop the tree in the hole...
Mast out Email .jpg

After it's all loosely connected, I go somewhere by myself to tighten things. It only takes a few minutes but inevitably, I tighten the rig after sailing a bit.

I look for a straight spar (sighting the mast track), mast and mizzen plumb, leeward stays only slightly loose in 15 knots or so.

The more important point is, what coin do you place under your step?
Mast base.jpg
 
May 25, 2012
4,333
john alden caravelle 42 sturgeon bay, wis
like guitars and pianos and all things with stretched steel cables, you will want to check the tune for every song for the best music.
we eyeball what the rig is doing during every sail. the alden with it's telephone pole like mast is pretty easy to keep in tune. the ascow needs adjustment with every tack. different hulls flex in different ways. it's not just the rig.
for me, having the vessel performing at it's best is one of the most fun parts of sailing.
adjusting leach lines on the sail happens constantly as well. halyard tension, outhaul tension ..... always tweeking :)
remember the kid in third grade that always had his zipper down from lack of awareness.
no one wants to be that guy :)
 
Jun 2, 2007
403
Beneteau First 375 Slidell, LA
I do have a Harken furler, and I guess I will have to look at the installation instructions more closely. I certainly didn’t see anything that resembled a type of turnbuckle adjustment when I put it together. I wish I had the instructions here rather than 1000 miles away.

I realize that the adjustment only affects the headstay length, but that is what I need. The mast needs to be raked back slightly from where it is presently.
The instructions I just looked up on the Harken website show the typical turnbuckle on the headstay, neither my original equipment headstay nor the new headstay I installed 2 years ago had a turnbuckle adjustment. Both headstays were products of US Spars presumably made to Beneteau specs.
These are the instructions for the MK 3 furler. Mine is older, a MK 1, but is pretty much the same. Page 23 describes adjusting the headstay length using the integral turnbuckle. (Evidently there are two page 23's, the description is on the page with pictures.)
https://www.harken.com/uploadedfiles/Product_Support/PDF/mk3-3-4867.pdf
If your model is different, then never mind.
Oh, and pay close attention to the adjustment range, to make sure you have enough thread engagement. It's all in there.
 
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Jun 24, 2014
80
Westsail 28 72 Long Beach , California
Fairly easy to do on our boat , It was a lot easier before we put on the roller furling . Fortunately for westsailors a user manual has been written and a nice description of the mast tune operation . Something you guys might find interesting , after you get the mast straight port to starboard you hang a weight from the back of the mast on the main halyard . The weight is lowered to just above the boom , you rake the mast aft so there is about a 8" gap between the mast and halyard .
 
Jun 25, 2004
1,108
Corsair F24 Mk1 003 San Francisco Bay, CA
like guitars and pianos and all things with stretched steel cables, you will want to check the tune for every song for the best music.
we eyeball what the rig is doing during every sail. the alden with it's telephone pole like mast is pretty easy to keep in tune. the ascow needs adjustment with every tack. different hulls flex in different ways. it's not just the rig.
for me, having the vessel performing at it's best is one of the most fun parts of sailing.
adjusting leach lines on the sail happens constantly as well. halyard tension, outhaul tension ..... always tweeking :)
remember the kid in third grade that always had his zipper down from lack of awareness.
no one wants to be that guy :)
Leech lines are for stopping fluttering of the leech tape, not for trimming or sail shape. High speed leech flutter causes the panel fabric to rip parallel to the leech, right next to the tape.

Judy B
 
May 25, 2012
4,333
john alden caravelle 42 sturgeon bay, wis
doc. you are correct, of course, for your stated function of the leach line. it is adjustable for that reason . no one yanks it tight and leaves it for the season. that's why my leach cords are adjustable. over tightening it is SLOW. just like dropping the flaps on a plane. so why do i adjust so much. well, i have five jibs to choose from. hank on sails. foils are too much work and i am not a roller reefing kind of guy because its slow. that's right , i said it. i'm more than willing to do the work. well, as the wind changes, and the jibs change each hoist will have a different halyard tension. just like we change the main halyard tension for different wind speeds. well you set the leach after you set the halyard and the sheet. you pull the leach till it just takes out the flutter AND NO MORE, cause it's slow. all the endless contraptions to ease sail handling, well............................................... none of then ever claimed they make you go faster. if you choose to sail dynamically, as i do, then of course you will be adjusting the leach cord with every sail. the adjustment will be different with the same sail for a hard on beat then for a reach.
now, these are all choices, and nothing more. i choose to sail dynamically. but that's only for me. i and my crew like doing the work. we think it's fun. i am fully aware that most sailors could care less about adjusting all the little nuances, but we love doing it. most sailors don't want their bottom racer smooth, we do. we love getting out of the cockpit and dialing her up.

so yeah, we adjust the leach cord as it was designed to do.
 
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Sep 20, 2014
1,320
Rob Legg RL24 Chain O'Lakes
I find that tune relative to the condition of the main sail. As the sail get a little bagging, putting a small amount of bend in takes the bag out. I don't know if the sail was made for pre-bend, but it is now. Since this is a trailer sailor, the mast is put up every time I go out. Since the baby stays never see any real tension, I can use those for a guide as to how much pre-bend the mast should have. If they both clip into place relatively easy, but have no slack, then I know the mast is where I had previously set it.
 

mm2347

.
Oct 21, 2008
241
oday 222 niagara
First, start by I. D.ing your rigging wire. Stretch can indicate the amount of load . Find the amount of stretch that happens at a given load for a given length. This info. is available in a number of tuning guides online. The measurement can be done with masking tape and a tape measure. For example, your 7 x 19-316 S.S. 1/4 wire stretches 1/16 of an inch at 15% load for or every 10 ft of length. (made up numbers) Pay close attention to how the specs. are written. Start w/ a just snug rig and mast in column. At the proper dimensions put fine line marks on the wires. Start low and tighten in small equal amounts side to side until the desired stretch is reached.
Many lee side stays on boats with deck stepped masts will be slightly loose in stiff winds. This is probably the cabin top and or deck sides adding much to the overall flexing. Do Not tighten your stays past the recommended amout given by the wire (or rope) manufacturers. As to what is max amount of stretch? Anything over 25% I would double check at other resources. If I did go over 20% I would back it off after the race.
 
Feb 15, 2008
183
Hunter 49 Sydney
So I consider myself relatively well skilled on all aspects of sailing, yachting etc with the exception of the rig and I would class myself as a novice at best. After some 14 years it is now roughly pretty good. All the so-called riggers didn't have a clue. So the rake has never been right, the prebend has never been right, the bend is not even as it should be and the tension well that's another story. It would seem the right tool is a loose gauge which not one rigger has bought to the boat and some don't even know what that is, let alone realize to my surprise they don't make one big enough. Then lets use a tape measure to measure the stretch..... really... So I will purchase a laser measuring tool.

So when do you replace what. Many insurances companies stipulate 10 years and your supposed to replace the lot. Im guessing that means it should be good for 15 years which is about where I'm up to, but who knows maybe its good for 20 years. But what to replace, besides the wire and is all 316 stainless wire the same, do you actually need to replace the turnbuckles or just the cotter pins. Do turnbuckles actually break, and what about the fittings on the end of the new wire are staylocks as good better or worse.

Then I will get to tunning and the Selden instructions while pretty good are also a bit of a joke, but its far from easy or straight forward for me. My prebend is no longer induced. With the rigging all slack, there is residual prebend in the top half, so inducing an even prebend without increasing it in the top section is tricky, and you cant make it straight anymore. Like many yachts, we have added davits for our tender, maybe added a rigid Bimini, and perhaps on there is solar panels, maybe you just put starlink up there as well. All of which results in dragging your arse through the water, and hence now your rake is wrong, so you crank the forestay up as far as possible letting some off the caps which are now extend as far as can be done safely. You use your measure tap to get an idea of the stretch ( I will use a Lazer ) The forestay tension/bend is quoted as 13" (not sure the exact number) But in the middle, because you can of course stand on your sky hook or go up there in your Bosen chair to measure the forestay sag in 15-20 under load...... Really and this is all simple to you lot
Given I have seen 60knots more than once and 8m (24ft) sea's I need to get it right and for me yea its not simple.
What see going on out there is equivalent to people sucking there finger holding up and saying the wind is blowing 15 knots from the south :(
 

dLj

.
Mar 23, 2017
3,370
Belliure 41 Sailing back to the Chesapeake
@Screen Saver you replace everything - turnbuckles, connectors, the whole system. If your insurance requires 10 years, then that's your answer if you want it covered under insurance. The time requirement is a difficult one to answer given the significant differences in use and location.

Without going into a long explanation, all 316 is pretty much the same.

As far as measuring stretch with a LASER or tape measure, good luck with that. Wire rope needs tension measured. The loos gage is designed to approximate that. Don't know what size rigging you have but there are loos gages for pretty big stuff.

All your pre-bend talk is beyond me. I have no idea what mast you have. I run a cruising boat. Mast is a straight column.

This is a 5 year old thread. Not everyone that was part of the original discussion is still around....

dj
 
Oct 19, 2017
7,732
O'Day 19 Littleton, NH
My prebend is no longer induced. With the rigging all slack, there is residual prebend in the top half, so inducing an even prebend without increasing it in the top section is tricky, and you cant make it straight anymore.
That sounds like an issue you should be addressing beyond tuning. $ makes these problems easy to put off. Good luck. Hope you can get back out there and sail as soon as you can. That's what all of us hope for. Be safe.

-Will
 

JBP-PA

.
Apr 29, 2022
389
Jeanneau Tonic 23 Erie, PA
I have those baby stays that I was told would reduce any mast pumping. So far all they have done is chaffe the main sail and take up deck space.
There are two different things called baby stays. Some are inner forestays used to fly a staysail, sometimes removable when not in use. The other purpose is on masthead rigs that don't have both forward and aft lower shrouds such as older Tartans and some Hunters. These masts can pump severely leading to mast failure, so a babystay that is very small is is rigged to stop the mast pumping.
 
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JBP-PA

.
Apr 29, 2022
389
Jeanneau Tonic 23 Erie, PA
What kind of furler do you have? The Harken furler on my boat has an integral turnbuckle that adjusts the length of the headstay, but you would never know it without looking at the installation instructions. That being said, you would only adjust the headstay length to change the mast rake, not rig tension.
It is common on some boats to use toggle plates to preset a fixed forestay length instead of a turnbuckle. You can still change the forestay length by using different toggles, or you could replace it using the traditional turnbuckle setup.
 
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