26M replacement daggerboard

[BOAT]

If I am reading their chart right, the largest shot is "English" size LG at 9.1 mm (In "American" talk that means "Triple Ought Buck Shot")


Let's see, . . 9.1 mm equals somewhere around . . 0.358268 inches give or take a few thousandths (my eyes on this ruler I have are not too good) . . so the decimal equivalent of .3582 is . . .lets see . . nearest 32nd of an inch so .3582 times 32 and rounding and . . . . what? Eleven?? Is that right?? ELEVEN? Eleven thirty twos? That many thirty twos?? ( gee whiz I wish I was not so stupid).

What is that? 11/32 ?? (Where the hull is Tom when you need him??)

HEY TOM!! This is bigger than 1/4 but smaller than 3/8 . . . right?

(This is why all the rest of the world went to the metric system - geeeze, let's wait for tomfoolery to figure it out for us).

[Tomfoolery]

More like 23/64".

[sailboatmike]

But you want to use the smallest balls you can so you dont lose as much space as the round balls sit on top and next too each other.

[BOAT]

But you want to use the smallest balls you can so you dont lose as much space as the round balls sit on top and next too each other.

Indeed, but at the same time you need to allow the water to drain out - that means there will be drain holes in the bottom - if the shot is too small it will fall out of the holes.

[Seapup]

Do you think you could get some #7-1/2 (2.3mm/0.09 inch diamter) lead shot into your dagger board? Something like this https://www.amazon.com/Eagle-Magnum-Lea ... =lead+shot

If it works, you can pour it out, melt it and pour it back in.

Thats exactly what I did on my centerboard.

I read every post I could find before doing it. On the centerboard there are reports of it swelling if you add too much lead, it sounds like the construction is thin.

Indeed, but at the same time you need to allow the water to drain out - that means there will be drain holes in the bottom - if the shot is too small it will fall out of the holes.

I don't think you can realistically use loose weights and water, its one or the other.

I used #8 Shot, its tiny, there is virtually no empty space when its poured in. Maybe an 1-2oz of water could disperse into a bucket of 50lbs of shot, its that densely packed.



On the centerboard I closed the drain holes with 5200 and drilled a hole at the top to pour it in. The first 25lb all fit at the very tip, maybe bottom 2-3", the next 25lb filled it to about 12", the third bag filled it almost to the top as the body of the board is pretty much solid fiberglass.

To raise and lower the board I used a cascade with a single block from a 4:1 for a total of 8:1 without too much friction, worked well. Wife could pull it up easily enough, we did not use a winch. This is a pic as I was figuring out the raising tackle (photobucket decided to keep all my mod pictures)


My thought was if I didn't like it I would redrill out the drain plug and drain the lead. I liked it and kept it.

[BOAT]

This is an X boat?? Man, my eyes must be all screwed up. So you raise and lower the centerboard on the X boat with a block on top of the deck??

I could really use your help on this, but first I need to figure out which boat we are talking about.

[sailboatmike]

Maybe more numerous but smaller drain holes Boat, maybe 4 x 1/8" holes instead of 2 x 1/4" holes

[sailboatmike]

Im still waiting for the figures of how much weight in the keel is worth in comparison to water in the ballast tank.

I sort of figure given the raw numbers that its 1 to 3, being 1lb in the keel is worth 3lbs in the ballast tank, my thought is I would like to be able to sail without the tanks full in LIGHT winds and only use the tanks if it gets up above maybe 12knts.

My X is one of the first off the production line and as such has smaller ballast tanks, the later ones hold 650 liters (650kg) mine has only 550 liters (550kg), I know many of the racing boats of the same size and carrying around a lot more sail area are ballasted to between 150 and 300Kg.

We got slaughtered last time we raced in light winds for a number of reasons (main one is I'm a crappy sailor) but many of the boats we were up against had a all up displacement of around 1000 to 1200Kg, us on the other hand are up around 2000Kg, not great in less than 5knts of wind with brand new starched sheet sails,

That wasnt all my fault, wind was predicted at 10knts variable, and the new sails we pointed and ran with all but the sport boats when the wind actually did hit 10 knts for a few minutes, in fact we were giving some of these expensive racey sailors heart palpitations as they couldnt pull away from a Mac

Alas the wind died and we just about sat still while the lighter weight boats with worn in sails kept going.

[Highlander]

Plug the D/B fill it with sand at no cost & try it & see if it work,s for u , if not un-plug it & flush the sand out ?

J

The density of sand isnt great, one would need a large volume, sand is only about 2.5 times the density of water at 2.500kg per cubic meter. Iron may be better at 7.870kg per square meter or just over 3 times that of sand but of course the winner of common metals is lead at 11.340kg per cubic meter or better than 5 times that of sand.

So if you wanted to put in say 50Kg of sand (100 odd pounds) that would need a good size bag, given the thickness of the keel you would probably struggle to get that much sand into the space.

A nice 250mm dia (10 inch) by 25mm (1inch) thick piece of steel in the bottom of the centerboard would be the most economical way to give it a go and even thats only 19kg or about 50lbs, but I would expect 50lbs 5 feet below the water would make a real difference

Yes but once the sand is wet it is heavier , fill a 5 gal pail with sand & weigh it then add water & weigh it again

J

[sailboatmike]

But water weighs nothing in water, so there goes that theory

[BOAT]

But water weighs nothing in water, so there goes that theory

True, because water floats in water.

[Highlander]

But water weighs nothing in water, so there goes that theory

It's the same thing as ur water ballast once you start to heel it will take effect
J

[sailboatmike]

But water weighs nothing in water, so there goes that theory

It's the same thing as ur water ballast once you start to heel it will take effect
J

Well this is one of the great fallacies that people that have "Real Sail Boats with tons of lead below the water line" like to throw at Macgregors, they cant self right because the water ballast is in the water.

The answer is NO the water ballast isnt in the water, the water ballast is in a sealed compartment in air and thus works (not overly efficiently) but it works, as well proven but those neanderthals dont really have the brain power to work that out

[BOAT]

But lead IS heavier than water, right? I mean the only reason I'm thinking of putting lead in the DB is to make it heavier when it's IN THE WATER - have I got that right?

[sailboatmike]

Yes Boat, LOTS of lead maybe a bulb on the end too