Proper Tensioning of New Headstay with Roller Furling

[osirissail]

Originally Posted by Bash

Your boat was built in 1971, so I'm assuming your mast is 40 years old.
At that age, if it ain't broke, don't fix it. Take the sag out of your forestay by tightening the backstay. That will help you point higher.
Don't mess with an old mast.

Very good advice - older masts were built like telephone poles - very straight and rigid. They do not tolerate bending and will snap or break if bent more than a little. "Rake" or leaning the whole mast aftwards was used in conjunction with a cunningham or moveable boom gooseneck that allowed the sail to be pulled down or relaxed.
- - Modern masts have a tapered form and sometimes come with a built in bend (not straight). They are also built to allow flexing in the fore/aft axis.
- - So the advice is critical - don't mess with an old mast by trying to use it like a modern mast.

- - If your deck-stepped mast is "rotated" at the deck shoe/mount something is seriously wrong. Either the deck shoe/mount has snapped or has bent bolts or the cabin top deck there is rotten. It will take some serious repairs to straighten the deck shoe/mount so that the mast is again solid and aligned correctly. And it is an important job to undertake right away or you may find the base of your mast "kicks out" sideways while under sail and the whole rig come down.
- - Tensioning amounts and procedures for the standing rigging can be found in the Brion Toss books and DVD's.

[highseas]

The sail was made before I lessened the bend(not rake).The guy from North Sails didn't say anything about excessive bend when he measured it up.I never noticed the problem till later.The pumping is reduced for sure but now I wonder about sailcut being right.Sailmaker is in Vancouver,boat in Mex.The boat is so balanced it steers with little weather helm.

[Cheechako]

Hard to say, but being a cruising boat, he probably didnt count on a lot of bend. See how it looks when you're sailing.

[nv5l]

The foot of the mast has a cast aluminum foot with a tenon sticking down into a mortice in the step. There's a little play, so I think I just need to loosen the stays/shrouds and align it.

I'm just not sure I can do that myself without unweighting the mast. I can just barely lift it when it's on the ground -- it's just under 40'.

[osirissail]

Originally Posted by nv5l

The foot of the mast has a cast aluminum foot with a tenon sticking down into a mortice in the step. There's a little play, so I think I just need to loosen the stays/shrouds and align it.

I'm just not sure I can do that myself without unweighting the mast. I can just barely lift it when it's on the ground -- it's just under 40'.

What I was getting at is there should be no ability of the mast to rotate more than an 1/8" or less. The shoe/bracket is normally shaped such that the mast shape is captured and cannot be rotated or moved. If there is an ability to rotate the mast then look for the reason. It could be a broken "shoe/bracket" that holds the mast; or the bolts that go through the deck are bent or loose allowing the whole shoe/bracket to rotate; or a rotten deck underneath that also allows the shoe/bracket to rotate.
- - In any case, unload/slack the shrouds and stays and then try to rotate the mast. Again if it rotates anymore than a really small fraction of an inch, something is wrong. And rotation out of alignment that is visually noticeable most likely is a warning that something is wrong, broken or rotten.
- - Normally only the little "trailer-sailors" type boats with removable masts have any degree of slack such that the mast could rotate out of alignment fore and aft.

[nv5l]

I'd say it's about 1/8" or so, but I've got a really good eye for this sorta thing and would prefer it was perfectly aligned. The step is the same shape, but about an inch wider all the way around, so an 1/8" really shows up, if you're looking for it. The rigger didn't catch it, and I only noticed when I started re-tuning it.

Everything is original with no damage, but once it's loaded, believe me, it's not going anywhere. I doubt I could even move it unloaded. It's probably over 200 pounds rigged.

[FloridaWriter]

Originally Posted by nv5l

I replaced all my wire, and the rigger who helped step the mast suggested I bend the mast so she would point better -- he'd had a similar boat, so I thought it was a good idea.

However, he's more into racing and is now in Europe racing other folks boats -- I'm not into racing.

Anyway, it looks like my headstay is way too loose (almost sloppy), but since it's roller furling, I can't check the tension. To fix it, I'm planning to loosen the backstay, adjust the shrouds as necessary to make the mast vertical, then slide the furler up and tension the headstay and backstay in concert, keeping the mast vertical.

I was considering putting a little bend in her, but am unsure how to go about it. Any advice would be great. I guess I could make her straight, do some sailing, then adjust, but am curious about how much tension to use and how to control the headstay tension. I have a Lose gauge I can use for all the other wires.

thanks...
don

I don't believe your boat has a mast that is intended to be bent. Doing so may overstress the chainplates and accomplishes very little unless you are an avid racer. Raking the mast aft will increase weather helm to some extent; while raking it forward will reduce weatherhelm. Figure tensioning the shrouds and stays no more than 15 percent of breaking strength.

Good luck,

[Cheechako]

I never felt a cruiser should have the rig too tight, but not sloppy either. Often for shrouds and uppers I would go out sailing on a brisk, but not strong day and adjust the leeward set while under sail to weather. Often they go pretty slack. I just take them up until the wobble in the wire disappears. This ends up being pretty tight at the dock. It's nice to know your rig is tight and straight under sail.

[nv5l]

Thanks everyone. I took out the bend and pretensioned the cap shrouds and backstay to about 15%. The lowers are a little looser, but I had to tighten one side (the forwards) a little more to take a sideways bend out of the mast, but still a little less than the uppers.

I'm at anchor with a lot of chain out and listing a little while I work on the transmission -- one locker is empty. Once that's done and I haul in the chain, I'll get her trim and adjust again before taking her out for a final adjustment under sail.

thanks again...
don

[barnakiel]

On our boat (masthead rigged) we induce some pre-bend and it is still there no matter how hard it blows. I checked many times in all types of weather and the mast looks more or less the same both fore and aft and athwart wise. The mast is about 33 ft long, the pre-bend is about 2 inches. The sails are cut allowing for this pre-bend.

The forestay is pretty tight, not bar tight. The fact that there is a roller there does not change anything. Except, if the sail is fully furled and the boat rolls heavily, one can see the stay moving both ways. But I do not think there is much one can do with all the weight aloft.

b.