Ok, I need to ask here....
I just bought an '05 Nacra F18 which has several new features...duh, I haven't sailed a beach cat for over 20 years...I will have a session with the previous owner soon but this dagger board thread interests me.
I noticed in videos several leeward daggers in the air and partially inserted...but never thought the windward one (ie both) was in question. So, sailing tight, no prob...but if you head off the wing on a beamy reach, you need to partially raise it??
Thanks for this info, great stuff to know.
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Bert Scott
Niceville, FL
Nacra F18
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Snapped dagger
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Posted: Jul 19, 2011 - 02:39 PM
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Posted: Jul 19, 2011 - 03:29 PM
News to me also. I know that you raise the leeward dagger just to cut down on the drag but I have never heard of raising the windward dagger. I would have thought that they were designed to counteract the forces with the full length specifically on a beam reach. I know I certainly wouldn't design something that would fail when it encounters a design limit you know it will encounter... Everyone who owns a cat would have snapped a dagger by now.
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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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Posted: Jul 19, 2011 - 05:07 PM
A '76---'81 Nacra 5.2 is 30-35 years old. That leeward dagger (ie either dagger) has been bending back/forth well over a thousand times in that life span--and in the same spot!!! Take almost any material & do the same and you're bound to get a failure rate of 5-15%. It's only in the past maybe 10 years we.ve begun to see this problem. Same thing with hulls. I do not take my La Paz P-16 (with 350 injection holes in the hull) out in 5-6 foot waves in 15 knots cause I want to have it for a few more years. A new boat would be different. Pete -
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Posted: Jul 19, 2011 - 05:33 PM
Oh I agree, anything on a 30+ year old boat subject to fatigue loading is liable to break at some point.
But my point is, there is a line between being cautious and paranoid (everyone has to decide where it is). You have a boat that you, enjoy but you know there are problems with it and what they are so you compensate for that by sailing accordingly.
I have my 1981 Nacra 5.2, its my only boat and I have replaced darn near everything on her. As far as I know it only has two or three seasons of sailing on in and was stored the rest of the time, or the previous owner could have sailed the piss out of it (although it doesn't show it). So should I treat it like a 30 year old boat with 30 seasons under its belt or a 30 year old boat with 3 seasons? If I treat her like the former I am going to miss out on some great sailing! The only thing I know for sure is that I regularly check my boards and they are rock solid.
I'm not going to pull them up and lose performance just because they 'could' break. It is just about as likely that I am going to break a rudder or even the nose off of one of my hulls one day. If they break I will replace them or reconstruct them, same as with a new boat. They are expensive and/or a pain to make but that is part of owning a boat.
I guess what I am trying to say is that I would be more worried about keeping the regular maintenance up because preventing the a mast coming down on me is more important than preventing breaking a daggerboard by pulling it up on a reach. And I would sail the boat as intended (provided it is in good repair) until it breaks down. Then part it and buy a new one. :)
And if anyone knows of a source for cheap Weta boards, let me know.
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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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Posted: Jul 19, 2011 - 07:14 PM
OK, I like that logic and I'm glad this is a topic of aging not of normal performance. I believe my 05 boat will not need any concern in this area....but I will work to define, for myself, what is 100% and what is 80% for those years that are just around the corner.
Thanks for the discussion.
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Bert Scott
Niceville, FL
Nacra F18
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Posted: Jul 21, 2011 - 10:40 PM
$778 ?!?! I'm sitting on a stack of these. I'd say early retirement time...except:
They break.
I know of no upside to putting one down all the way on a reach, but I'm no expert.
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Rob
OKC
Pile of Nacra parts..
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Posted: Jul 22, 2011 - 07:53 AM
Yep that tears it. This winter I'm going to learn how to make a mould and start making them out of foam and carbon fiber/kevlar. I figure, I can make them and sell them for $350 and still be making about double my investment.
D.
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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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Posted: Jul 22, 2011 - 10:31 AM
Any way you can speed up production,and cut a brother at arms a deal?bulk rate?west coast distributor?or just bro deal .. I was thinkin all black hulls ,with the jolly roger painted on the daggers. yeah stick to the code.We should get in touch, a contractor i sub for has a cnc machine and set op for 2and 3 pound stucco foam.Need to research ,what density foam how much cloth and glass.Boards need to break not dagger trunk ,am having issue with that taking on water not a lot.Just a thought,on the other side of the coin . With boards at 350 a pop,and whole sleds for 700 ,looks like a chrisning party sat for the pearl.Oh still down one board!
one board willie(79 nacra 5.2)
the pearl(81 nacra 5.2-saturday)
hulls-up boards80%-down
,,, ...
fillmore , ca -
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Posted: Jul 22, 2011 - 10:37 AM
Damm,I just read that i'll never be a writer! at least i'm good on the phone.
see above,,,... -
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Posted: Jul 22, 2011 - 10:47 AM
What about dagger board do it yourself kit? five blanks,directions,cloth,even a 20 min dvd ! wolf whats my cut
cat of the brain syndrome
no seeds no stems
hulls and boards
and a good idea every now and then -
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Posted: Jul 22, 2011 - 12:45 PM
Unfortunately I'm too busy doing real work right now. :(
You can buy the structural closed cell poly foam (airex or other brand) from many sources (don't have any handy right now). Or make a mold and use the 2 part expanding foam stuff from US composites. http://www.uscomposites.com/index.html
Cheaper alternative is to get some western red cedar or balsa blanks for the main body and glass it with fiberglass, carbon or carbon/kevlar. Its denser than the foam, but with a 30 year old boat weight isn't the most critical problem. In the case where you are glassing the blanks having a CNC router would be a huge advantage over having to sculpt them yourself!
There are some good instructions and videos on how to build the foils here: [url]http://www.uk-cherub.org/doku.php/tech/howto. Toughest thing would be if you want to vacuum bag them to get more strength out of the fiberglassing. Again probably not essential if you put a couple more layers on. I have a guy here who does sailboards that I might try and sucker (convince) into making a set of foils for me.
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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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Posted: Jul 22, 2011 - 06:08 PM
Here is the supply place i was thinking of to get the foam and other supplies: http://www.noahsboatbuild…ahmain/index.asp?url=IND Of course it's in Toronto.
D.
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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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Posted: Sep 25, 2011 - 09:52 PM
I've gotta reneg on this.. My 5.5 clearly steers better, with much less chance of the rudders breaking free of the water (cavitation?) if I have the dagger 80% or more down. I solo it all the time, which means I'm trying to depower a bunch, but its still a much better sail with the daggers down.
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Rob
OKC
Pile of Nacra parts..
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Posted: Oct 04, 2011 - 02:04 PM
I've had the centerboards on my boat flip up while on a beam reach a few times.
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Matt
P19MX #1055
Gulfport, MS
Matt922,
Loosen the set screw in the little puck at the top of your centerboard until the fit is tighter and your board won't pop up on you.
