Association Forum - Flattening Reef

Assn Members Area · Join

Home.

Association Forum

Ships Store

Cruising

Racing

Technical Tips

Photo Gallery - New

Boat Search - Updated

Manuals & Brochures

Swap Meet

Links

Officer Flag Line & Staff

Bylaws & Constitution

Members Area

Join the Association

Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.

Association Forum

Username:	Password:
Save Password
Forgot your Password?

All Forums

Catalina/Capri 25/250 Sailor's Forums

Catalina 25 Specific Forum

Flattening Reef

New Topic

Topic Locked

Printer Friendly

Author

Topic

Bill Holcomb
Admiral

Member Avatar

USA
769 Posts

Initially Posted - 03/15/2002 : 10:43:46

In answer to Duane's question regarding the flattening reef point in Snickerdoodle's mainsail.........
http://c25c250.best.vwh.net/restricted/sdflatreef.html

The flattening reef is a particularly nice option for a tall rig C25. The boat can handle a large jib well into moderate winds, but something needs to be done with the mainsail early on to avoid what many skippers call "form weatherhelm". That is, when the boat heels more than 20 or so degrees, the shape of the leeward side of the hull is so much rounder than the windward side that the boat wants to spin into the wind. (see my discussion of weatherhelm in the tech tips section http://c25c250.best.vwh.net/restricted/snkhelm.html )

One of the best ways to adjust the amount of heel is to flatten the mainsail. Start with the Cunningham and clew outhaul. If the boat is still heeling too much, the next step often is to tuck in a first reef. But, at 12 or 13 knots, this seems too early for many skippers and they fight the boat's weatherhelm. So, the addition of a flattening reef point on the mainsail's leech will flatten the bottom 1/3 to 1/2 of the sail quickly and efficiently, while not cutting back on the drive of the sail.

So Duane, is this a reefing system or a trimming system??? I don't know for sure. But, I do know that with the flattening reef tucked in at around 12 knots of breeze, I can sail faster and flatter than others who don't have the flattening reef available to them.

Bill Holcomb - C25 Snickerdoodle #4839

Edited by - on

Champipple
Master Marine Consultant

Members Avatar

USA
6855 Posts

Response Posted - 03/15/2002 : 13:22:34

Bill,

So here is the next question then. With the flattening reef, does the sail have to be cut for it, or is it as simple as having the loft put in another kringle?

Duane Wolff
"The Flying Wasp"
C-25, #401 std,sk
Chief Measurer C-25/250 national Org.
<img src="http://im1.shutterfly.com/procserv/47b2dc20b3127cce9cd2f45b211a0000004010" border=0>

Edited by - on

dlucier
Master Marine Consultant

Members Avatar

Virgin Islands (United Kingdom)
7583 Posts

Response Posted - 03/15/2002 : 14:56:07

From his picture in Tech Tip's, it looks like he has a double reef main that he tensions using one or two of his reef points to flatten out his main to depower the sail when a breeze freshens. When the wind increases more he could tuck in the first reef to depower the main.

Don Lucier, Northstar
C25 SR/FK

Edited by - on

John Mason
Admiral

Members Avatar

USA
687 Posts

Response Posted - 03/15/2002 : 19:26:11

The flattening reefs on the boats I've sailed (that had them) were at about the same position vertically as the cunningham. Think of it as the cunningham's opposite. It doesn't really reduce sail area as much as it just really flattens the bottom of the sail. Tension the cunningham and then tension the flattening reef and watch the boat stand back up. Just have the loft put in a cringle.

John Mason - Ali Paroosa
1982 - FK/SR #3290

Edited by - on

dlucier
Master Marine Consultant

Members Avatar

Virgin Islands (United Kingdom)
7583 Posts

Response Posted - 03/15/2002 : 19:41:00

Now I understand. Thanks.

Don Lucier, Northstar
C25 SR/FK

Edited by - on

Bristle
Admiral

Members Avatar

USA
834 Posts

Response Posted - 03/15/2002 : 20:35:24

<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>
From his picture in Tech Tip's, it looks like he has a double reef main that he tensions using one or two of his reef points to flatten out his main to depower the sail when a breeze freshens. When the wind increases more he could tuck in the first reef to depower the main.

Don Lucier, Northstar
C25 SR/FK
<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

Don: From the picture, I'd say Bill's flattening reef cringle is barely a foot above the foot of the sail--not the level of a normal first reef point. However, since he then shows it pulled all the way down to the boom, I have to wonder whether it should be just a little higher to allow for Father Time's inevitable stretching. (Or maybe it once did allow for that.)

Dave Bristle, 1985 C-25 SR-FK #5032 "Passage" in CT

Edited by - bristle on 03/15/2002 20:37:18

Edited by - on

dlucier
Master Marine Consultant

Members Avatar

Virgin Islands (United Kingdom)
7583 Posts

Response Posted - 03/15/2002 : 21:18:20

So if the flattening reef cringle is an altogether separate cringle from the regular reef cringles and it is only a foot up from the boom, could this be considered the ".5" reef point since it is before the 1st reef point????????

Don Lucier, Northstar
C25 SR/FK

Edited by - on

Steve Milby
Past Commodore

Members Avatar

USA
5908 Posts

Response Posted - 03/16/2002 : 10:46:49

The flattening reef is very useful, and can be added very inexpensively to an existing mainsail. The flattening reef helps keep the boat upright as the wind increases. It works in several ways. It slightly reduces the sail area, it slightly lowers the center of effort on the mainsail, it moves the center of effort of the entire sailplan slightly forward, and it takes some of the excess sailcloth out of the pocket along the foot of the sail, so that you can flatten the mainsail. All of those changes help the boat point to windward, and relieve the pressure on the tiller. One of the best advantages of a flattening reef is that you can tuck it in much more quickly and easily than a full reef, and you can shake it out in a flash. When your opponents are laboring to windward under too much mainsail, but they don’t want to take the time to tuck in a full reef, and when a full reef really is not needed, you can quickly tuck in a flattening reef, keep your boat upright, and out point and out foot your opponents.

On a tall-rig C-25, the flattening reef is also useful when cruising, to lift the boom a foot, and give you more boom clearance in the cockpit. As Dave pointed out, it doesn't drastically reduce the drive of the sail, but, when you're cruising, speed isn't a top priority anyway. You can relax and not worry so much about someone getting clobbered by the low-hanging boom of the tall rig.

If you are buying a new mainsail, I suggest you get both a flattening reef and a shelf foot. A mainsail with a shelf foot has such a deep pocket along the foot of the sail that it looks like you could set your drink on the shelf foot without spilling it. It gives you more power in light air, and while reaching and running. It helps you drive through waves and boat wakes. When the windstrength increases, and the boat begins to heel excessively, the flattening reef flattens the mainsail by taking the deep pocket out of it, and helps you stay upright. Using the two together gives you a broad, adjustable power range from light air to moderate air, when sailing both on and off the wind. They are not expensive options on a new sail.

Also, the shelf foot looks really cool, it gives you one more adjustment to play with, and your cat can sleep on the shelf foot, until you tack!

Steve Milby "Captiva Wind" C-25 T/FK #2554

Edited by - steve milby on 03/16/2002 15:24:18

Edited by - on

Bill Holcomb
Admiral

Members Avatar

USA
769 Posts

Response Posted - 03/17/2002 : 07:43:27

<Duane, "Does the sail have to be cut for the flattening reef?">

No, I had the flattening reef included when I ordered the new mainsail a few years ago. Gary Swenson at Ullman of Ventura made the sail and put the flattening reef in at a point about the same height up from the boom as the Cunningham grommet on the sail's luff. So, John Mason's description is right on. Any mainsail could have the flattening reef added.....inexpensively - as Steve mentioned.

So, my mainsail has the flattening reef that flattens the bottom 1/3 of the sail allot for when the breeze gets into the 11 to 13 range. The flattened main still drives the boat really well and is plenty powerful. But, the boat doesn't heel as far and develop weatherhelm. If the wind gets up in the 15 to 16 knot range, I usually tuck in a first full reef........and a second full reef at about 22 to 25 knots.

Bill Holcomb - C25 Snickerdoodle #4839

Edited by - on

Topic

New Topic

Topic Locked

Printer Friendly

Jump To:

Association Forum

Notice: The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.