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Catalina/Capri 25/250 Sailor's Forums

Catalina 25 Specific Forum

Backstay and Forestay tension

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JanS48
Navigator

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USA
141 Posts

Initially Posted - 06/20/2015 : 21:20:46

Greetings all, today was a milestone day, the mast is now up on my 82 C25 STD rig, It's still on hard but should hit the water next weekend.
I do however have a question: How does one know when there is enough tension on the Backstay and Forestay ? The Forestay seems difficult since I have the weight of the CDI furler luff on it.
My 'guestimate' method was to sample some other boats in the yard and set to a similar tension. BTW - I didn't get the sag out of the furler luff til I tightened the backstay a significant amount. The mast looks straight but honestly I'd never be able to tell if it was a few inches either way.

Any Suggestions?

82 C25 SR FK
Sailing out of Newport Harbor.

wanderer13
1st Mate

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USA
76 Posts

Response Posted - 06/21/2015 : 05:39:44

Jan,

Not sure if it's the "right way", but I attached two plumb bobs (the pencil bobs) fore and aft on the mast, about 7 or 8 feet up. If the mast is straight, both bobs fall plumb and contact the mast slightly. I tensioned the stay turnbuckles bit by bit to achieve the right tension and a straight mast.

Glad to hear you got the mast up!

James

1981 Catalina 25 FK/TR

Steve Milby
Past Commodore

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USA
5851 Posts

Response Posted - 06/21/2015 : 06:06:36

After you have made the mast erect, then the next objective, with a jib furler, is to put just enough tension (and no more) on the forestay and backstay to take most of the sag out of the forestay. If the forestay sags too much in light to moderate winds, the boat won't point well to windward. But, don't put too much tension on the rig in search of "perfect" pointing ability. If you put too much tension on the forestay, the furler won't roll freely.

Steve Milby J/24 "Captiva Wind"
previously C&C 35, Cal 25, C25 TR/FK, C22
Past Commodore

Derek Crawford
Master Marine Consultant

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USA
3312 Posts

Response Posted - 06/21/2015 : 09:15:18

Steve, how does the name of your Cal translate?

Derek Crawford
Chief Measurer C25-250 2008
Previous owner of "This Side UP"
1981 C-25 TR/FK #2262 Used to have an '89 C22 #9483, "Downsized"
San Antonio, Texas

Stinkpotter
Master Marine Consultant

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Djibouti
9013 Posts

Response Posted - 06/21/2015 : 09:48:28

FWIW, I found that I got the slight weather helm I preferred on my SR with a furling 130% by raking the mast back slightly, so that the main halyard would hang about 4-5" behind the mast at the boom level. The upper shrouds and forward lower shrouds were just barely tight enough to not go slack on the leeward side, while the leeward aft lower would wave a little in the breeze. But all were tensioned when the boat was at rest so the mast was "in column". If I grabbed the non-adjustable backstay and tried to wave it, I could get it to oscillate by maybe a foot. (That was my substitute for a Loos gauge.) All of this was based on the advice of a rigger who had a serious off-shore racing sailboat and a Finn class boat that he also raced (but no C-25).

If you change the rake, you generally need to make some slight adjustments to the lower shrouds--the uppers aren't affected. (The latter is probably not true on a C-250.)

Dave Bristle
Association "Port Captain" for Mystic/Stonington CT
PO of 1985 C-25 SR/FK #5032 Passage, USCG "sixpack" (expired),
Now on Eastern 27 $+!nkp*+ Sarge

Edited by - Stinkpotter on 06/21/2015 10:01:14

Steve Milby
Past Commodore

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USA
5851 Posts

Response Posted - 06/21/2015 : 11:47:42

quote:
Originally posted by Derek Crawford

Steve, how does the name of your Cal translate?

Fahrvergn�gen was an advertising slogan used by Volkswagen in a 1990 U.S. ad campaign that included a stick figure driving a Volkswagen car. The word means "driving enjoyment." My boat is black with a white deck. The stick figure is painted on both quarters in bright yellow, and it's also printed in black on the bright yellow mainsail cover. The PO named it, and I haven't changed it, although I admit that I still have to google it to spell it correctly. I've been thinking about having a battle flag made for it, with a bright yellow VW Beetle rampant on a field of black.

Steve Milby J/24 "Captiva Wind"
previously C&C 35, Cal 25, C25 TR/FK, C22
Past Commodore

Steve Milby
Past Commodore

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USA
5851 Posts

Response Posted - 06/21/2015 : 12:01:53

Regarding the rake, the owner's manual says to get the mast erect, fore and aft as well as laterally, and then to sail the boat in about 10 kt winds and take notice of the amount of weather helm it has. If it has too much, tilt the mast slightly forward to reduce the weather helm. If it has too little weather helm, tilt it slightly aft. After my C25 was commissioned by the dealer, it had too much weather helm, so I adjusted it gradually forward until it had a nice, light weather helm that didn't make me arm weary when sailing closehauled in a breeze.

The more weather helm the boat has, the more rudder you need to apply to keep the boat from heading to windward, and applying rudder creates drag, which slows the boat and prevents it from pointing high. Don't overdo it in search of more speed and pointing, because lee helm is just as bad as weather helm. To correct lee helm, you also have to apply the rudder, which also creates drag. The ideal is a light weather helm.

Steve Milby J/24 "Captiva Wind"
previously C&C 35, Cal 25, C25 TR/FK, C22
Past Commodore

Stinkpotter
Master Marine Consultant

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Djibouti
9013 Posts

Response Posted - 06/21/2015 : 20:37:14

I hate to disagree with Steve, but lee helm is much worse. It's dangerous (if you let go of the tiller, the boat falls off the wind and eventually jibes instead of luffing up), and, in moderation, it's slower than a neutral helm (according to my aforementioned rigger-racer). A little weather helm is a very important safety feature, and makes the boat somewhat faster to windward (according to several experts I've heard and read). The combination I appreciated was a little weather helm and the balanced rudder I bought from Catalina Direct, which greatly reduced the pressure on the helm. The tiller was still a few degrees to weather from on-center on a beat, but with one-finger pressure. "Power steering!" But let go (or fall overboard), and the boat stops. That, to me, is as good as it gets! (Although I never fell overboard.)

Dave Bristle
Association "Port Captain" for Mystic/Stonington CT
PO of 1985 C-25 SR/FK #5032 Passage, USCG "sixpack" (expired),
Now on Eastern 27 $+!nkp*+ Sarge

Edited by - Stinkpotter on 06/21/2015 20:42:28

Steve Milby
Past Commodore

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5851 Posts

Response Posted - 06/22/2015 : 07:43:17

There's no disagreement when one is talking about apples and the other is talking about oranges. I was talking about boat performance and you're talking about safety.

When we were first learning to sail, our instructors told us that, if the boat was heeling too much and we thought we were losing control, all you had to do is let go of the tiller, and the boat would head into the wind and go into irons. If you tune the rig so as to create lee helm, you will eliminate that effect. Letting go of the tiller will cause the boat to bear off the wind until it gybes, causing the situation to go from bad to worse. That's another good reason to not tilt the rig so far forward as to create lee helm.

Steve Milby J/24 "Captiva Wind"
previously C&C 35, Cal 25, C25 TR/FK, C22
Past Commodore

Stinkpotter
Master Marine Consultant

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Djibouti
9013 Posts

Response Posted - 06/22/2015 : 12:26:36

quote:
Originally posted by Steve Milby

There's no disagreement when one is talking about apples and the other is talking about oranges. I was talking about boat performance and you're talking about safety...

...and performance. It's been explained to me that a boat is slightly faster to weather with slight weather helm than neutral or lee helm--my understanding was weather helm adds some pressure to the windward side of the keel, improving its lift, and maybe also its righting force. But of course too much will add enough drag to negate that. How much is too much? The answers I've heard are over about 4-5 degrees of tiller deflection. I think of it as too much if I'm hearing turbulence from the rudder, and I generally had about 3 degrees. (But I didn't race my C-25 except when another boat was on the same heading...

)

Of course sail trim can affect the helm--we're talking about behavior with "ideal" trim for speed and pointing to windward.

Dave Bristle
Association "Port Captain" for Mystic/Stonington CT
PO of 1985 C-25 SR/FK #5032 Passage, USCG "sixpack" (expired),
Now on Eastern 27 $+!nkp*+ Sarge

Derek Crawford
Master Marine Consultant

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USA
3312 Posts

Response Posted - 06/22/2015 : 13:29:48

Thanks Steve. I knew that I had heard that word before, but couldn't remember where. I remember VW's ad campaign very well.

Derek Crawford
Chief Measurer C25-250 2008
Previous owner of "This Side UP"
1981 C-25 TR/FK #2262 Used to have an '89 C22 #9483, "Downsized"
San Antonio, Texas

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