Is my 150 genoa too much sail for my CD25D?

[Andy Denmark]

I don't mean to insult your intelligence here but your own words say you're new to sailing and the boat. It sounds like one of your problems might result from improper setup. Set the car by bisecting the clew angle and moving it aft one hole. This is the initial position and it should be close to correct. For light air, set halyard tension so there are barely discernable horizontal wrinkles along the luff -- no tighter. The sail should trim in to 2 -4 inches off the spreader. Telltales should all be spaced aft of the luff tape 8 inches; three evenly spaced along the luff is fine and not close to a seam. The leech should be a smooth curve with its max depth roughly at 50% height but roughly straight with no twist.

Mainsail: set the traveller amidships, halyard tension to just enough to pull out the scallops. Outhaul loose enough so there are no horizontal wrinkles or folds. Topping lift loose and floppy. Vang loose. Trim the main in until it has a "bubble" at the luff that goes roughly 30% up from the boom. DO NOT trim until there is no bubble or flutter as this is seriously overtrimmed and will result in excessive weather helm because the sail is stalled and will result in heavy weather helm. A single telltale on the leech at the end of the second batten from top should stream aft

Helm: (very basic here) Should have slight weather helm with tiller 4" or so from amidships. Steer to keep telltales streaming parallel with constant angle of heel. If necessary, EASE the traveller down to flatten the main. Sail to keep angle of heel constant & telltales streaming. Do this enough and this will become unconscious (a sort of muscle memory, I guess) and takes a while to master.

Two pictures here: first is a CataHuntaTeau from astern looking straight up the slot from astern. This is good sail trim for wwd in light air. Note smooth curve of leech and the main bubble is (barely) visible.

Second picture is my boat, Rhiannon, showing the "bubble" more clearly (hard to visualize white-on-white sometimes). Note shape of slot. Outhaul is too tight (large foot wrinkle), and angle of heel. This pic is in 6-8 kts wind and boatspeed is 4.4 mph. Note forward placement of crew.

Try these and see if they help. I hope so.

Andy

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[David Morton]

Andy, thank you for your insight. While my trimming skills are probably not going to win me any serious races, I think I pay pretty good attention and all the things you mentioned are on my mind as I sail. The issue, I don't think, is not so much the details of my trimming skills, but rather the question of whether or not the sail plan for my CD25D can make good use of a 150 genoa. So far I'm hearing arguments for both sides and clearly it depends on the particular sailing conditions where one lives. I'm just concerned that I seem to sail 90% of the time with the jenny partly furled and wonder if that is the most efficient use of this size headsail. Perhaps as the summer wears on, and I find myself sailing in lighter air more often, I'll be able to make better use of the sail. In addition, I think earlier mainsail reefing may allow me to keep more headsail out. Right now, though, it seems that I might have been better served with a 120 or 130, rather than the 150. But, ENOUGH WHINING!! I think I'll just go sailing!

David

[Andy Denmark]

Okay, david,

To address your question I'll give you my opinion from experience as a sailmaker.

With their relatively small foretriangles, a 150% genoa is a good sail for the CD-25 -- providing you use it within its design parameters. It will work fine up to ~15 kts before reefing the main and a second reef tied in at ~22 kts. Where these break points occur largely depends on the sail cut, trim, and the way you sail the boat. Above these "break points" you can start to furl the genoa. Note that the first step is to tie in reefs, not to furl the headsail

The problem with a large furling headsail is this. In order to be an effective light air sail it must be constructed of lightweight sailcloth. The material is usually too light to hold up under the loads put on the sail in higher winds. It stretches excessively, especially the aft part of the sail that isn't furled, the portion of the sail that's actually working. Enough of this loading in excess of the loads the material is designed to withstand and the sail loses its shape, i.e., "blows out." The material loses elasticity and is permanently stretched. For all practical purposes the sail is now virtually useless as an upwind sail that's trimmable. When the luff is flat the leach is flogging. When the leach is controlled, generally by moving the car forward or with a leach line, the sail is luffing at front or has so much hook in the leach as to disrupt laminar flow across the sail. The net result of all this is inability to "point'" excessive weather helm, or increase in heeling moment.

IMHO, the better choice for an all-purpose sail is a 125% or 130% genoa of heavier material (for obvious reasons). The general rule for furling down is a 15% reduction in LP. For example, if you have a 115% LP headsail that means you should furl it down no further than 100%. Often reinforcing patches are put in on the leach and foot at these selected furling percentage points as the edges are where the loads are highest. Be sure to move the car forward as you furl down to keep decent sail shape.

So, there you go. Hope this is helpful.

Andy

[Joe Myerson]

IMHO, the better choice for an all-purpose sail is a 125% or 130% genoa of heavier material (for obvious reasons). The general rule for furling down is a 15% reduction in LP. For example, if you have a 115% LP headsail that means you should furl it down no further than 100%. Often reinforcing patches are put in on the leach and foot at these selected furling percentage points as the edges are where the loads are highest. Be sure to move the car forward as you furl down to keep decent sail shape.

I agree with Andy, and my own genoa is a 130%, which I often sail furled when the wind pipes up on Buzzards Bay.

However, it also depends on where you're sailing. On Long Island Sound, for example, I wouldn't hesitate to have a 150%. I'm not sure what your conditions are, David, but I wouldn't get too afflicted with second-thoughts.

Remember to reef your main at about 15kts and 22kts (approx.), and you'll really enjoy your 25D.

Good luck,

--Joe

[Neil Gordon]

I'll just point out that if you look around to the other boats to see if it's time to reef, you'll reef too late. I'm often the first (and only) to reef as the wind passes the mid-teens, with no loss of speed.

[David Morton]

Thank you all for helping me sort this out. I have gone out several times since this thread started and have been making adjustments as suggested. I believe I probably have been over sheeting my main and not reefing in a timely manner. Since I'm such a lousy judge of wind speed ( anemometer on my wish list) I think I'll just let the boat tell me when to reef. If I seem to have to let out the mainsheet beyond just the bubble that Andy suggests, in order to keep her on her feet, I think it probably is time to reef. This seems to be working for me now and allowing me to make use of more headsail, which the SOG really seems to like. Planning on a week cruise starting this weekend to give me plenty of time to play with sails and trim. Look for me on Muscongus and Penobscot Bays.