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Old 16-10-2014, 18:30   #1
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Dual furling headsails - minimum separation & other concerns

My pointy old boat and I have done about 50k offshore miles with a furling genoa and a removable inner forestay with a couple hank on sails. I've raised the 90% jib a number of times over the years and the storm jib once.

As time passes I find that I am far more reluctant to go hang out on the foredeck. The genoa has been taking more of a beating than necessary because of that lazy/safety decision.

I am considering replacing the removable stay with a second furling. My problem is that there is minimal separation between the two. I have about a foot space at deck level and eight inches up top. The rigger who helped put it together back in the early days insisted that with my heavy mast I could get away without runners. The inner forestay attaches 18" below the masthead, with a very heavy wrap around plate and about a dozen fasteners.

So will this work? Adding runners and moving the deck attachment aft would be just about impossible with all the cruising gear that is piled all over the boat (dinghy in front and solar aft). It looks to me like there should be space, and by slacking the leward genoa sheet when sailing the staysail, as I do now, there shouldn't be a chafe issue. I realize it means no more short tacking on the genny, but I'll have to live with that.

Any educated opinions will be gladly appreciated.
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Old 16-10-2014, 19:27   #2
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Re: Dual furling headsails - minimum separation & other concerns

I have what you are proposing. Originally I had a removable inner forestay but I found it to be a p.i.t.a. (not to mention issues trying to store the hank-on sails when not in use).

I recently changed out the removable stay for a permanent installation and now have the 130% genoa on the forestay and an 80% yankee on the inner. Both stays have Furlex 300 furlers. The deck attachment points are a little over a foot apart.

Structurally I think you are probably OK without the running back-stays however an easy way determine this is to plot it out. Project the line of the inner stay and see where it intersects the backstay. Ideally it will intersect the backstay at the backstay's point of attachment to the headbox (or tree). If it's close I wouldn't worry too much but if it's miles away you may require the backstays. I have attached my instructions to the rigger who did my installation.

Alternatively Selden recommend: "(if) the cutter stay is located 3 - 6% of the height of the foretriangle below the existing forestay ... (then) ... running back-stays are not required" - see attached extract.

Hope that helps.
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File Type: pdf solent stay intersect.pdf (117.8 KB, 71 views)
File Type: pdf Page from selden catalogue.pdf (274.7 KB, 54 views)
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Old 10-03-2015, 10:40   #3
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Re: Dual furling headsails - minimum separation & other concerns

I have decided to go ahead with this change, but have one more decision to put before the group.

The old removable stay was attached to a large stainless tang that is bolted to the mast. The external halyard block is attached to a 1/2" thick welded aluminum tang about 8" lower on the mast. I intend to run an internal halyard so this tang would be redundant if I use the stainless tang.

I am inclined to remove the stainless fitting and use the aluminum tang to attach the upper end of the new furling. This gives me double the separation from the fore-stay at the top.

My concerns are if the tang is strong enough and will be an adequate attachment point. I'm also more than a bit nervous about getting the 1/2" hole close to perpendicular. The existing hole is a 5/16" that took the shackle pin for the halyard block. It will need to be cut away since it is too close to the edge of the material to be enlarged.

I'm attaching photos of the existing set up, and the proposed mods to the aluminum tang. All thoughts will be appreciated.
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Old 10-03-2015, 11:05   #4
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Re: Dual furling headsails - minimum separation & other concerns

I put my money in the SS tang, but anyway the other one looks fine to me to if is thick enough and have a good Weld around, a good trick is to fabricate a slot window in aluminium and brace the actual plate with rivets and a Weld line around, like many multi rigs outh there with the aluminium uppers tangs, that way the risk of cracks around the Weld is eliminated ... Cheers,
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Old 10-03-2015, 19:13   #5
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Re: Dual furling headsails - minimum separation & other concerns

OK. But if you go for the alloy tang then where do you attach the halyard?

Is there another halyard entry below this alloy tang?

PS I would make this tang stronger too - say extra plates, riveted onto the extrusion.

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Old 10-03-2015, 22:27   #6
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Re: Dual furling headsails - minimum separation & other concerns

Quote:
Originally Posted by neilpride View Post
I put my money in the SS tang, but anyway the other one looks fine to me to if is thick enough and have a good Weld around, a good trick is to fabricate a slot window in aluminium and brace the actual plate with rivets and a Weld line around, like many multi rigs outh there with the aluminium uppers tangs, that way the risk of cracks around the Weld is eliminated ... Cheers,
I'm not sure I understand. Are you suggesting a plate around the tang that is welded to it? If so, I'm afraid I don't think I can get a welder up the mast.

The aluminum tang is 1/2" thick, and the weld looks beefy and clean, all the paint damage and corrosion is where the shackle beat up the paint over the years.

I do intend to run a new internal halyard.
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Old 10-03-2015, 23:00   #7
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Re: Dual furling headsails - minimum separation & other concerns

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Originally Posted by romanystar View Post
I'm not sure I understand. Are you suggesting a plate around the tang that is welded to it? If so, I'm afraid I don't think I can get a welder up the mast.

The aluminum tang is 1/2" thick, and the weld looks beefy and clean, all the paint damage and corrosion is where the shackle beat up the paint over the years.

I do intend to run a new internal halyard.
Hard to explain, is like a chainplate cover as a example, in aluminium, the edge sides are riveted to the mast and the inner slot edges are welded to the tang, i know you cant Weld up there, but i see few of this aluminium uppers tangs with cracks in earlys Zspar or older marechal now Z difusión spars, now those Multis are hig loaded in the uppers shrouds , now they fit a aluminium cover around the tang and Weld the inner part with the edges riveted, i have a old Lagoon mast in the shop , probably i can take a pic tomorrow and post it here, bt im not sure if it have the tangs improved with the cover, i check tomorrow.... probably your tang should be fine with the inner furler..

And i guess your actual shackle tang is the OEM furler or inner forestay tang, then dont make any sense to make such a beefy tang for just a shackle with a block .. and the SS tang plate is just add it for someone??

Cheers..
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Old 11-03-2015, 07:35   #8
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Re: Dual furling headsails - minimum separation & other concerns

I believe half an inch thick alloy plate is great news.

This is your inner forestay so you will be able to keep eye and (if necessary) improve. You can also see alloy strength in tables and see if this is enough. On our boat the plates are 200% strength of the wire (but I do think a higher margin is better).

You may, however, like to improve corrosion protection around the hole: maybe a new ss inset and then very thorough clean and new paint job. Mind there will be a toggle there now - plenty of SS to react with this thick alloy tang. A stay, because of the load and constant movement, could try to chew on the alloy plate.

I am not sure how the ss insets are set. I have seen them blown in on production tangs but sure there is also some mechanical gimmick that could be used, perhaps thread and "loctitite" method (???)

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Old 11-03-2015, 11:01   #9
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Re: Dual furling headsails - minimum separation & other concerns

I'm actually responsible for both tangs.

I had the stainless one fabricated 25 years ago when I originally installed the inner fore-stay. It has two holes in the tang, one for the stay the other for the halyard. This proved to be a problem with the halyard too close to the stay.

Ten years ago I had the mast pulled and refinished. The shop in Seattle that did that work added the aluminum tang. I have a vague memory of them saying the tang was fabricated with a T base internal to the mast before instalation, but wouldn't bet more than a beer on it.

What do you think of making a press/locktite in SS insert that is a tight fit on the pin and extends a bit on both sides of the tang? A piect 5/8" long, 1/2" ID, 5/8" OD?
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