Cadet/General Bouyancy question

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jules22
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Cadet/General Bouyancy question

Post by jules22 » Mon Jun 26, 2017 8:39 pm

My daughters Mk2 wooden cadet ( front and rear tanks) holds a huge amount of water when dunked, I had wondered about straping a couple of bouyancy bags in the open spaces under the side decks.

Plan being that the bags help fill up the big void under the side decks, that scoops up all the water when you upright the boat, so less water to bail out (theory).

However........ I do wonder if the extra bouyancy will make the cadet float much higher above the water when on its side,
making it hard for a child to get up on the dagger board !.

Anyone with any practical expierence of this ?, before the bank of Dad stumps up for a pair of bags.

Stephen Hawkins
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Re: Cadet/General Bouyancy question

Post by Stephen Hawkins » Tue Jun 27, 2017 11:59 am

You are right to be concerned, as it will sit higher in the water and be more likely to turtle, which will make recovery all the more difficult.

Compound that with the fact that the Cadet is not really fast enough for a self bailer to work, unless empty, i.e. when you do not need it.

People have often added side tanks to the original mk2 design and taken the opportunity to open the cockpit up by reducing the width of the side decks and therefore the tanks. But still the problem remains to some extent. Later marks dispensed with the rear tank.

My son had a very old Cadet Mk2 at SCSC with no self bailer. The bottom line was, stop capsizing, or learn to get over the side onto the centre board before you reach the point of no return. This he eventually got down to a fine art.

Its getting a bag that is long enough, not too wide, as you do not want to encroach into an already small cockpit. And you have to factor in the thwart. Do you put the bag above or below it.

Might be worth just putting a smaller sail on and reducing the likelihood of a capsize in the first place.

regards

Steve
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Rupert
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Re: Cadet/General Bouyancy question

Post by Rupert » Tue Jun 27, 2017 7:13 pm

My memory of the old style side decks was that the waterline was below the edge of the deck when capsized, so the boat came up dry. Old man faulty memory of teenage years?!
Rupert

jules22
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Re: Cadet/General Bouyancy question

Post by jules22 » Tue Jun 27, 2017 7:50 pm

A mark 2 defo comes up full of water ! (big bucket needed to bail), side tanks would be ideal ( mk3 conv !) but no time to do as it is sailed every week.

Rather than blow up bags , I might experiment with foam insulation cut to fit the available space, duct taped together and straped into the cadet with 25mm webbing.

I have most of the bits kicking about , so not the end of the world if its no good.

jules22
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Re: Cadet/General Bouyancy question

Post by jules22 » Fri Jun 30, 2017 5:19 pm

Anyone know if Celotex ( foam insulation with a foil backing) used in house building takes up water ?.

A mate who is a builder has some off cuts going begging, but not sure if it "soaks" up water over time. :?

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jpa_wfsc
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Re: Cadet/General Bouyancy question

Post by jpa_wfsc » Sat Jul 22, 2017 8:33 pm

If you make the cadet float very high when on its side smaller crews will definitely struggle to get up on the board if they are in the water and it will turtle very quickly - but if you feel they are nimble enough to go over the top on capsizes - then that will not be a problem. A mast head float (until they have got the over the top style sorted) will avoid you spending your afternoons de-turtling graduates.

IS Celowhatsit an expanded polystyrene type? It will not absorb any water, but, will trap water against any surface it is held close to. This will promote rot. Bags are probably better as they will give more airflow around them to allow the surfaces to dry. But as you say - you have the foam insulation available to experiment with so go ahead - maybe remove it at the end of the season?
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Ed
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Re: Cadet/General Bouyancy question

Post by Ed » Mon Jul 24, 2017 9:01 am

I don't think celotex will work well.....

although it is closed cell and hydrophobic.....I still suspect it will absorb some water and it is just pretty horrible stuff.

Some of the other foams would be ok, like jablite or jabfloor which are expanded poly boards, or the blue/pink stuff which is used for flooring. They both cut and can be shaped easily enough. the problem with the celotex is that it brakes up too easily and the surface is softish and comes off on your hands like a kind of 'grit'.

Best wishes

eib
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ent228
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Re: Cadet/General Bouyancy question

Post by ent228 » Mon Jul 24, 2017 9:20 pm

Celotex has glass fibre reinforcement. It is really itchy and horrible. I have used loads of it.

However if it is available then if you were to wrap it in tape then it might be a good idea. Maybe cut pieces to fit into Rubble sacks and tape the whole lot up?

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Nessa
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Re: Cadet/General Bouyancy question

Post by Nessa » Sat Jul 29, 2017 8:53 am

I have a Cadet. The best solution is a mast head float and a pair of big hailers, plus a bucket in the safety boat.
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