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T O P I C R E V I E W
AlMo
Posted - 06/25/2019 : 08:14:13 Has the mainsail (appears to be the original one) on my 1978 Catalina 25 actually shrunk? It goes up to full hoist, but lacks a good 18-24" with full outhaul. Maybe the boom itself is from a larger boat?
6 L A T E S T R E P L I E S (Newest First)
Steve Milby
Posted - 06/25/2019 : 11:47:29
quote:Originally posted by AlMo
I wonder if any sailmaker has had the challenge of building a main that goes all the way out the boom?
When I ordered my new C25 in 1980, I ordered it without sails (At that time Catalina sails didn't have a very good reputation. Now they're much better.) and then I ordered a set of sails from North. The North mainsail was cut for racing with a very full roach, a racing shelf foot and a flattening reef. The roach was so big that, for a long time, every time I tacked, the batten ends snagged on the backstay, and I had to stand on the cockpit seat and shake the backstay to get it free. After a few years the sailcloth softened and the sail didn't snag very often.
Under the racing rules, the length of the foot of the C25 mainsail cannot exceed 9' 7". There is no limit on the length of the leech or the size of the roach. North pushed those measurements to their limits. My point is that there are limits, both mechanically as well as under the racing rules, to how big you can make the mainsail. The backstay is a limiting factor. The sails North made were legal under the rules, and very fast.
quote:Really I am getting used to a 135 Genoa that I bought with the roller furler last year, and I am trying to get the two sails to work together better in light air.
Sailing well in light air has much more to do with sail trimming and boat trimming techniques than with the size of your sails. If you think about it, in light air you want to maximize your sail power and minimize drag. You maximize sail power by powering up your sails in every possible way. Ease both halyards (it deepens the drafts of both sails), ease the mainsail outhaul (which also deepens it's draft), ease the backstay adjuster if you have one, move the genoa cars far forward, then move all your crew weight to leeward and forward, next to the shrouds. By moving crew weight to leeward, you cause the boat to heel. When the tip of the mast leans to leeward, gravity causes the sailcloth to hang in the smooth, curved shape that drives the boat, instead of hanging straight down like a sheet on a clothesline. By moving crew weight forward to the shrouds, the boat's fat transom is partially lifted out of the water. By reducing the boat's wetted surface, you significantly reduce drag, and with less drag, the boat goes faster.
If you use all these techniques, you'll sail well in light air.
Stinkpotter
Posted - 06/25/2019 : 10:53:24
quote:Originally posted by AlMo
...I wonder if any sailmaker has had the challenge of building a main that goes all the way out the boom? Guessing that may overpower the boat in stronger winds, though.
Really I am getting used to a 135 Genoa that I bought with the roller furler last year, and I am trying to get the two sails to work together better in light air. Seems like the new jib rides up a good foot or two higher than the prior, non-furled version (a 150 so longer and lower foot).
If the main reached the end of the C-25 boom, its center of effort (CE), and thereby the CE for the whole rig, would be further aft--that would increase weather helm. Our C-25 standard rig with 130% roller furling genoa had just about perfect, light weather helm.
The roller genny typically has a higher clew to help it roll more compactly on the furler. You don't want the foot of the sail rolling on top of itself--that would create more of a bundle at the bottom and poorer shape when the furler is used to reef.
islander
Posted - 06/25/2019 : 10:23:18 If you want to measure, The boom extrusion not including the two end castings is 10'4" The stock Catalina sail has a foot of 9.58 Extending the sail farther aft might create a conflict with the roach of the sail and the backstay every time you tack.
AlMo
Posted - 06/25/2019 : 10:10:57 Thanks for the replies, Bill. In my non-naval-architect mind, this "boom authority" and the short, aft-located traveler probably go hand in hand with the small-looking mainsail? I wonder if any sailmaker has had the challenge of building a main that goes all the way out the boom? Guessing that may overpower the boat in stronger winds, though.
Really I am getting used to a 135 Genoa that I bought with the roller furler last year, and I am trying to get the two sails to work together better in light air. Seems like the new jib rides up a good foot or two higher than the prior, non-furled version (a 150 so longer and lower foot).
Thanks, Alex
Bill Holcomb
Posted - 06/25/2019 : 08:24:50 Of course, cabin top sheeting would get in the way of the pop-top... Bill Holcomb
Bill Holcomb
Posted - 06/25/2019 : 08:23:31 The boom and sail are probably the right size. Catalina designed the boom to extend farther aft over the cockpit so that the mainsheet would have better mechanical advantage. If we had cabin top sheeting like some of the C27s or Capri 26s, the boom could be shorter. Bill Holcomb - C25 Snickerdoodle #4839
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.