mast bouyancy

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Phillip Lee
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Joined: Mon Nov 02, 2009 2:48 pm

mast bouyancy

Post by Phillip Lee » Tue Dec 14, 2010 4:59 pm

Has anyone tried to seal the mast to stop or slow the ingress of water, down here in the sunny Solent especially with wind over tide a capsize quickly ends up as inversion. This effectively is game over as the righting operation can take a while.
I have sailed with a foam plug at the masthead with a halyard hole through the middle. The jib halyard slot is taped to leave only a small hole. The result is sometimes effective as this buys 30 seconds or so, but in big waves not so good. The hounds are sealed with silicone.
I wondered of anyone had a better solution than me? I could imagine the jib halyard being led round a block near the hounds and back down the luff maybe. Another line to lead up the foredeck to a cleat.
I could always practice more and not fall over....

Rob
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Joined: Fri Jul 18, 2003 7:53 am
Location: Emsworth Hants United Kingdom

Re: mast bouyancy

Post by Rob » Wed Dec 15, 2010 6:35 pm

Phil, there is a big problemb with part restricting the holes in your mast as it drastically increases the time it takes to drain the water from the mast prior to righting the boat, the mast will stick to the water for a long time as water cant drain quickly. You either need to fully plug it watertight or allow it to drain quickly. If your going to try & make the mast water tight then you'll need an external anchor plate for the shrouds & forestay. You'll also need external halyards which will give a lot more of windage. For the main hal you'll need to try & get hold of an external halyard lock that fits on the top front of the mast & locks the small wire halyard with a long rope tail that hangs down the mast. Finn's & OK's used to use them, Needlespar did them but you'll have to do a bit of hunting around to try & find one suitable for the Canoe. The Proctor(Selden) halyard locks were only suitable for internal halyards & were very twitchy & no good for an external hal. As for the jib, you'll need to swage a block & eye to the top of the forestay & run a jib hal inside the zip luff or stuff luff, back to the forestay attachment on the deck, back through a block to a cleat on the aft of the foredeck where you can keep the jib hal tale tidy. Restricting the holes the way you currently have done it is the worst of both worlds. Try & get into the habit of never leting go of the mainsheet if you fall out of the boat, it will help pull you back quickly & also pull the mainsail in slowing it from inverting & then get on the plate as quick as possible. Practice your capsizes as much as you practice your tacks & gybes, their all a big part of sailing the Canoe.

michael Brigg
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Location: Gosport

Re: mast bouyancy

Post by michael Brigg » Thu Dec 16, 2010 8:04 pm

I think the Dart catamaran employs a halyard lock. (It also has a rotating mast)

I have been told that if you keep the boat from inverting, this can cause the boat to blow away from you. (Another reason for holding on to the mainsheet.)

The Original firefly mast was sealed,(made in 1946 - 1970's by Reynolds) having a wooden topmast, and also rotating. The sealed, bouyant mast was even advocated in the firefly as a safety feature!

The wire main halyard was led back through the Luff groove. This worked OK until induced mast bend opened up the groove and the halyard jumps out, "bowstringing" in a Chord, from the masthead to the foot :evil:

It was most likely to happen if you had a wire halyard, but is solved by a modern non-stretch rope. This is thicker than a wire, and so less likely to squeeze out of the groove, but thin enough to fit back down the luff. If of course used with a masthead halyard lock, you dont need to worry about the halyard jumping out of the groove as it will not then be under excessive tension.

My IC (Torment 102) is preserved in its 1960's format, with a very pretty mahoghany centreplate, and a very heavy over-rotating Gold anodized Proctor "C," unsealed and an absolute certainty to roll bottom up. When I get her back on the water I have thought even about fitting a mast float. This will be something to look forward to as I have never sailed a canoe before!
Michael Brigg

K102 "Torment." Cold moulded Nethercott
K203 "Moonshadow" Carbon "Pyranha" Nethercott (Spare boat. Needs a polish)

mikeewart
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Location: Leighton Buzzard

Re: mast bouyancy

Post by mikeewart » Fri Dec 17, 2010 3:16 pm

I use a masthead float in bad conditions on GBR 250, I have one which fits in the luff groove so does not disturb the airflow at the top of the rig too much, also in the extreme conditions losing drive at the top of the mast isnt a concern of mine. This is my first year of IC sailing and an inversion really does give me great problems, so this seems to be a solution until I get a lot better or the wind is kinder to me.

jimc
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Re: mast bouyancy

Post by jimc » Fri Dec 17, 2010 9:14 pm

mikeewart wrote:I use a masthead float in bad conditions on GBR 250,
Just make sure you don't sail without good safety cover. A Canoe on its side will go blow downwind faster than you can swim, so unless you are sure your safety cover will spot your head whilst you are still alive...

Steve Clark
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Re: mast bouyancy

Post by Steve Clark » Fri Dec 17, 2010 11:49 pm

Last go round in the states, we tried using a sealed masthead with a peg that stuck out the top for mastheads. These were left over Optimist sprit ends, and we didn't have time to make halyard sheaves and halyard locks. We have to tip the canoes over and pull the sails down from the top and slide a loop over the hook.
It works less well than we hoped and even with a long bit of line and a block at deck level, getting the sail on is a bit of a chore.
It does win on the cost and simplicity front however. And I do like having the top mast sealed, with the T terminals gooped up, the new IC will float on it's side quite happily. The canoe doesn't blow away very fast unless you manage to get the sail up wind of the hull, but even then the seat is in the water and slows things down pretty well. If you fall off when the boat is going very fast, it will crash quite far away, and then it can be hard to catch up. In all the years of sailing an IC I have only "lost" the canoe once and that time it had a 5 0r 10 meter head start in a Force 6.

The drainage holes should be at the bottom of the mast, and they should be as big as you dare make them.
SHC
Beatings will continue until morale improves

Phillip Lee
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Re: mast bouyancy

Post by Phillip Lee » Sat Dec 18, 2010 7:48 pm

Good to get a spectrum of advice on this. Almost all of my capsizes end up with me between the hull and the boom/rig. The lazy man's route to the board is over the top, climbing on anything in the way. I have a dislike of going underwater with unseen ropes in the way, I hate swimming round as there is little to get hold of as the boat drifts downwind. Hence my preference for a rig that floats. I have drain holes in the base of the mast which work well once the rig is coming up, with 15' of water pressure behind. Rob has a good point that drainage at near horizontal angles is poor. ok, what about an inflatable bladder in the topmast? needs some thought I will admit as to how to route the main halyard through.
I think the jib halyard running up the luff might be possible and difficult to mock up for a trial. Might do that when spring arrives. A mast section with a wide luff track, built into the section would let us route the main halyard through there.
I had an Australian Moth once with a piston type of sail release, a bit like is being described. It worked very well, but rigging a canoe on the side would be a pain.

jimc
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Re: mast bouyancy

Post by jimc » Sat Dec 18, 2010 8:12 pm

Phillip Lee wrote:but rigging a canoe on the side would be a pain.
The trick to doing this is to have a specially designed launching trolley. Some of the Australian classes do this: think of a gunwhale hung type trolley, but with two cradles and and the bars going past the gunwhale and locating it sideways, while a conventional cradle takes the hull. You tie the boat down to the trolley, roll trolley and boat over, and pull the sail down from the top of the mast. With a two hander in many ways its less hassle than faffing around with halyards and stuff. With a singlehander I think on the whole its less hassle to have the halyard.

wee mcp
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Re: mast bouyancy

Post by wee mcp » Sun Dec 19, 2010 12:18 pm

I think the jib halyard running up the luff might be possible and difficult to mock up for a trial. Might do that when spring arrives.
Hi Philip,
For a number of reasons I sail with a jib roller and therefore have to have the jib halyard running back down the (inside) of the jib luff - I use a zip luff though this is not necessary, just a bit tidier.
Let me know if you're interested and I'll sketch the contraption out for you.

Mast head floation:

Have you seen this: http://www.jonti.co.uk/html/accessories ... loats.html

Two blow-up sausages attached with sailcloth .. wraps round the luffrope and gets hoisted with the sail. Total max buoyance 8kgs, more than enough for an IC. :D

Ian McP
"Sometimes its a boat, sometimes more of an accident .. It all depends" - Pooh Bear
IC GBR305

mikeewart
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Location: Leighton Buzzard

Re: mast bouyancy

Post by mikeewart » Sun Dec 19, 2010 1:21 pm

Have you seen this: http://www.jonti.co.uk/html/accessories ... loats.html

Two blow-up sausages attached with sailcloth .. wraps round the luffrope and gets hoisted with the sail. Total max buoyance 8kgs, more than enough for an IC. :D

This is what I use there is more than enough bouancy there, I can climb up the hull from the inside to the board quite easily the mast dips under but pops back up quickly it also makes the recovery quicker as the mast is on the surface the whole time.

Phillip Lee
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Joined: Mon Nov 02, 2009 2:48 pm

Re: mast bouyancy

Post by Phillip Lee » Sun Dec 19, 2010 7:06 pm

A sketch of a jib luff halyard might be useful, though I can visualise how it might work.
I must admit I was thinking of an internal bouyant bladder , or foam. I,m not sure of the aerodynamics of external devices, after all we pay sailmakers lots for a nice sail. Pity to ruin things. Plus from an ego point of view it does say 'I capsize all the time'. Not too proud to admit that but don't want it written large!

mikeewart
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Re: mast bouyancy

Post by mikeewart » Mon Dec 20, 2010 4:02 pm

Plus from an ego point of view it does say 'I capsize all the time'. Not too proud to admit that but don't want it written large!
At our place the comment is keep out of his way he's going for broke today, it does affect the sail airodynamically but when I need the float I would have that section of the sail depowered anyway, I do find the extra weight aloft feels slightly different on a fast gibe though.

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