Optimum Sail Material for Large Performance Cruiser, Chapter 12

[a64pilot]

Originally Posted by Dockhead

All of a sudden, and for the first time I’ve ever experienced in a lifetime of sailing – the boat is fastest on a close reach, actually just off of close hauled, where I sometimes see boat speed of 80% of the true wind speed. That’s at 40 to 45 degrees AWA.

I'm a true neophyte, with a not fast boat and crappy sails, but my boats sweet spot is at 45 to 60 degrees, not a beam reach. My Aeronautical Engineer here at work is a racer and basically his answer is, "that's not right", I had always assumed I'm not trimming correctly, and or my windex is out of wack, but I've calibarated the windex at least to direction and it still seems my boats sails fastest with the wind at 60 degrees apparent. I'm assuming it's the staysail and it's effect on the slot that's doing this, but I'm looking at it with limited aeronautical experience, no racing and very little sailing experience, but I'm guessing that the staysail really affects the slot when going to windward?

I'll never see 80% of wind speed though, if I crack 50%, I'm grinning.

[Garrettw]

Dockhead, can you remind us of the manufacturer of you furling mast?

[estarzinger]

Originally Posted by rgleason

Thanks Evans, Do you think the newer 3Di are Ok for UV? Evidently they have a paint that is applied to the exposed area and it washes/wears off over time and can be reapplied. There is not much history with these sails, and they are a little more expensive than the 3DL.

Yes, 3Di if properly specified are quite durable and uv resistant (by high end sail standards) - IMHO twice the life of 3DL. They are also expensive. They are also typically heavier than 3DL. And personally I don't think the cloth has a very nice feel/"hand" . . . . Feels a bit like heavy plastic tarp to me. But they are excellent sails.

[FLJim]

If you're on a beam reach (90 deg true wind angle) going 50% of windspeed, then apparent wind angle will be 60 deg.

[Dockhead]

Originally Posted by Garrettw

Dockhead, can you remind us of the manufacturer of you furling mast?

Selden.

[a64pilot]

Originally Posted by FLJim

If you're on a beam reach (90 deg true wind angle) going 50% of windspeed, then apparent wind angle will be 60 deg.

Maybe it's as simple as that then, at least in my case anyway, because I do usually see 50% of windspeed, sometimes a little but not much more.
It's the simple, obvious things that elude me, thanks

[Dockhead]

Originally Posted by FLJim

If you're on a beam reach (90 deg true wind angle) going 50% of windspeed, then apparent wind angle will be 60 deg.

A beam reach is when the apparent wind is approx. 90 degrees, not true.

60 AWA is a close reach.

[estarzinger]

Originally Posted by Dockhead

A beam reach is when the apparent wind is approx. 90 degrees, not true.

just out of curiosity . . . do you have an official sort of source for that definition? eg its apparent wind rather than true that is the defining metric?

I ask because my understanding is that there has never been a clarified official sort of definition, all the existing definitions I have found are ambiguous. I have previously looked, but perhaps you have found one that I have not.

[Dockhead]

Originally Posted by estarzinger

just out of curiosity . . . do you have an official sort of source for that definition? eg its apparent wind rather than true that is the defining metric?

I ask because my understanding is that there has never been a clarified official sort of definition, all the existing definitions I have found are ambiguous. I have previously looked, but perhaps you have found one that I have not.

No, I haven't, and you are correct that it there do not appear to be any authorities on point. We discussed it here:

http://www.cruisersforum.com/forums/...nd-144708.html

But -- as various people in that thread point out -- defining a point of sail by reference to the true wind is nonsense. True wind on a moving boat is a mathematical construct (as someone said) -- you don't feel it, and you don't trim your sails to it. Moreover, when term "beam reach", and other terminology for points of sail was invented, no one even had any way of calculating true wind.

You can imagine an extremely fast boat in very light wind experiencing 30 degrees AWA when the true wind is on the beam -- his sails will be trimmed in tight and he will be as hard on the wind as anyone can be. Not just a super fast boat -- an ordinary boat motorsailing could experience the same. Is that a "beam reach" -- of course not.

[Garrettw]

Originally Posted by Dockhead

Selden.

So a nice wide slot for the battens then. My previous boat had a Selden furling mast; fantastic design. I have a Z-Spar now and I'm not sure battens would be as unnoticeable as you are experiencing.

[rgleason]

Evans thanks, very helpful. Will post some other info on 3dl and 3di. I guess I should ask for weight/sf of each material and actually see the 3Di.

[BigBeakie]

Reviving an older thread here, but does anyone have feedback or informed opinion on Norths new 3Di Nordac which seems too good to be true?

Is this the perfect Dacron cruising sail?



Sent from my iPad using Cruisers Sailing Forum

[estarzinger]

Originally Posted by BigBeakie

informed opinion . . . . 3Di Nordac

yea, I have an informed opinion.

It depends a bit on what your expectations are.

If you are looking for a good looking sail (shape and no mildew) for a mix of casual racing and weekend cruising with a 3 year life for a bit of a price premium . . . . then these will most likely be a good option. To compete with radial Dacron (which may or may not be a little cheaper) and lower end laminates (which probably will be lighter) and higher end laminates (which probably will be better performance but more expensive) & Hydra-net (which probably will be more durable but more expensive).

If you are looking for a live aboard, blue water cruising sail with a 15 year life (to replace a heavy crosscut sail) then . . . . we do simply don't know - North has not/does not really understand the long life span cruising market (a volvo or vendee circumnavigation is apples to oranges to a cruising circumnavigation), and these sails require significant designer input to achieve long life and we don't know how North will make that cost/profit trade-off.

It is still Dacron. And it is still glued together, just not with mylar any more. And there is less Dacron and more glue than in a woven sail. So don't expect a miracle.

As an aside, I do not like their marketing BS. These sails are simply not 'seamless'. They have very definite scarfed seams, which is somewhat different than say paneled sail plain overlap seams, but they are still very definitely seams - some of which (in prior d3i sails) have in fact historically failed.

[BigBeakie]

"It is still Dacron. And it is still glued together, just not with mylar any more. And there is less Dacron and more glue than in a woven sail. So don't expect a miracle. "

Thanks Evans, that is much appreciated! I was hoping you'd see the post

Our need is bluewater cruising for our new 50' cat, with alot of cruising in tropical areas, and hoping for at least 5 plus years from the sails.

Since the mylar laminates seem to have such a mold issue, that has scared me off them due to the time we'll spend in the tropics eg equatorial tropics.

And since it's a performance cruiser cat, straight Dacron will just bag out too soon.

The Norths expectation seems to be greatly extended sail shape life from their thermoformed Dacron, so I was surprised to hear you say 3 years is a more realistic expectation. Correct me if I'm wrong, but I'd heard Norths would warranty the sails for shape holding longer than 3 years, but maybe that's wishful thinking. I'm not expecting miracles, such as 15 years, but more than 3 years would be not unreasonable for the cost, I would hope. I wonder what their fine print says re lifespan?

So, assuming we are open to spending the budget for really good sails, where does that leave us?

Hydranet? I thought Hydranet has the resin flog out of them, and then they lose their shape holding, plus they are very stiff hand for flaking the main?

[TheThunderbird]

I chose Contender dacron, specific for tri-radial cut (100% jib on hooks)

it can sit on deck:-)

I wasn't convinced about the merits of hydranet (stiff, heavy, expensive)

as to laminates, low end ones are vulnerable ,the upper end ones being for rich racers.

Maybe, l will go laminate with the main