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17-06-2015, 19:16
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#286
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Senior Cruiser
Join Date: Aug 2009
Posts: 4,033
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Re: Bestevaer 49ST
I am assuming they are getting a carbon mast?
If so, the best of all worlds is a keel stepped one with a deck level plug/drain. That gives you the engineering advantages of the keel step (and I believe there are definitely some) with (almost - not quite complete because of a likely wire conduit in the mast thru the plug) the water resistance of deck stepped.
With an aluminum mast, I am not sure if there are adhesion and corrosion issues with the plug approach or not - the fact is the plus is hard to get perfectly way up in there . . . . unless you use a splice/butt joint, which we did in order to add a (tapered) internal sleeve from below the deck to just above the boom goose neck. We did that for two reasons - (1) because we wanted extra meat where the vang and gooseneck attached, because we have always found those parts under engineered for continuous water sailing">blue water sailing (and the wave cycling fatigue that involves), and (2) because we wanted that section to "always' be standing even if some other part above crumpled.
With a carbon mast you can just build the extra stiffness into the laminate schedule, and it is easier to get a perfect bond (and no corrosion concerns) with a deck level plug.
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18-06-2015, 01:32
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#287
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Registered User
Join Date: Mar 2011
Location: Caribbean
Boat: Oyster 66
Posts: 1,332
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Re: Bestevaer 49ST
Quote:
Originally Posted by estarzinger
I am assuming they are getting a carbon mast?
If so, the best of all worlds is a keel stepped one with a deck level plug/drain. That gives you the engineering advantages of the keel step (and I believe there are definitely some) with (almost - not quite complete because of a likely wire conduit in the mast thru the plug) the water resistance of deck stepped.
With an aluminum mast, I am not sure if there are adhesion and corrosion issues with the plug approach or not - the fact is the plus is hard to get perfectly way up in there . . . . unless you use a splice/butt joint, which we did in order to add a (tapered) internal sleeve from below the deck to just above the boom goose neck. We did that for two reasons - (1) because we wanted extra meat where the vang and gooseneck attached, because we have always found those parts under engineered for continuous blue water sailing (and the wave cycling fatigue that involves), and (2) because we wanted that section to "always' be standing even if some other part above crumpled.
With a carbon mast you can just build the extra stiffness into the laminate schedule, and it is easier to get a perfect bond (and no corrosion concerns) with a deck level plug.
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The plug is a great idea and without the mast join a real challenge too. I am sure the spar makers will find every reason why it can't be done! Actually I think the conduit part should be easy to seal. There are good external waterproof glands that will be used and the conduit can run to the base without sealing being necessary.
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18-06-2015, 06:34
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#288
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Moderator
Join Date: Jul 2007
Boat: Bestevaer.
Posts: 14,678
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Re: Bestevaer 49ST
Quote:
Originally Posted by estarzinger
I am assuming they are getting a carbon mast?
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Only a few of the Bestevaers I have seen have been built with a carbon mast.
My preference is for aluminium for a few reasons:
1. There seem to be more failures of carbon masts. However, many of these are on highly stressed racing boats where the mast has been built for absolute minimum weight, so it is hard to make a direct comparison of carbon and aluminium. Even so, I am not convinced the carbon alternative is as reliable.
2. Maintence.
It is very hard to get first hand reports of the maintenance issues. Epoxy has very poor UV resistance and I understand the mast is coated with a clear finish to protect the resin from UV. This needs to be reapplied. Every 4-5 years?
3. Cost.
We will not spoil the boat for a "ha'porth of tar", but cost is always a consideration.
Currently the mast is specified as an anodised keel stepped Selden. It has been specified by K&M/Selden as:
Mast section C304
Boom section B250
Total length is 22.29m. Above deck 20.02m
It has "compact" standing rigging (I presume this is Dyform).
Forestay 12mm.
Inner forestay 10mm
Back stay 10mm
Shrouds are 12mm
Intermediate shrouds are 12 and 10mm
I have requested a beefier gooseneck than normal (this seems a common failure point), but have not heard back how this will be done.
Quote:
Originally Posted by estarzinger
unless you use a splice/butt joint, which we did in order to add a (tapered) internal sleeve from below the deck to just above the boom goose neck.
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I like the idea of the tapered sleeve to strengthen the gooseneck vang. I agree these are weak points.
I am realising I don't know as much about mast construction as I should. Any other recommendations for the perfect cruising mast for this yacht?
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18-06-2015, 07:41
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#289
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Moderator
Join Date: Mar 2009
Location: Denmark (Winter), Helsinki (Summer); Cruising the Baltic Sea this year!
Boat: Cutter-Rigged Moody 54
Posts: 33,750
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Re: Bestevaer 49ST
Quote:
Originally Posted by noelex 77
Only a few of the Bestevaers I have seen have been built with a carbon mast.
My preference is for aluminium for a few reasons:
1. There seem to be more failures of carbon masts. However, many of these are on highly stressed racing boats where the mast has been built for absolute minimum weight, so it is hard to make a direct comparison of carbon and aluminium. Even so, I am not convinced the carbon alternative is as reliable.
2. Maintence.
It is very hard to get first hand reports of the maintenance issues. Epoxy has very poor UV resistance and I understand the mast is coated with a clear finish to protect the resin from UV. This needs to be reapplied. Every 4-5 years?
3. Cost.
We will not spoil the boat for a "ha'porth of tar", but cost is always a consideration.
Currently the mast is specified as an anodised keel stepped Selden. It has been specified by K&M/Selden as:
Mast section C304
Boom section B250
Total length is 22.29m. Above deck 20.02m
It has "compact" standing rigging (I presume this is Dyform).
Forestay 12mm.
Inner forestay 10mm
Back stay 10mm
Shrouds are 12mm
Intermediate shrouds are 12 and 10mm
I have requested a beefier gooseneck than normal (this seems a common failure point), but have not heard back how this will be done.
I like the idea of the tapered sleeve to strengthen the gooseneck vang. I agree these are weak points.
I am realising I don't know as much about mast construction as I should. Any other recommendations for the perfect cruising mast for this yacht?
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As a data point, my mast is about the same length (23 meters), but much heavier standing rigging -- backstay, forestay, lowers, capshrouds, all 14mm. 10mm backstay seems really skinny to me. But I guess they should surely know what they're doing. What's the sail area?
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18-06-2015, 08:10
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#290
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Moderator
Join Date: Oct 2008
Boat: Bestevaer 49
Posts: 16,151
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Re: Bestevaer 49ST
Quote:
Originally Posted by Dockhead
As a data point, my mast is about the same length (23 meters), but much heavier standing rigging -- backstay, forestay, lowers, capshrouds, all 14mm. 10mm backstay seems really skinny to me. But I guess they should surely know what they're doing. What's the sail area?
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Thanks for the info. It is great to have a comparison.
Is that 14 mm Dyform that you have? And is the 23m mast height from deck or total height?
Our sail area will be:
Main: 66.5 m2
Yankee: 49.2 m2
SWL
__________________
SWL (enthusiastic amateur)
"To me the simple act of tying a knot is an adventure in unlimited space." Clifford Ashley
"The cure for anything is salt water: sweat, tears or the sea." Isak Dinesen
Unveiling Bullseye strops for low friction rings
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18-06-2015, 08:32
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#291
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Senior Cruiser
Join Date: Aug 2009
Posts: 4,033
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Re: Bestevaer 49ST
Quote:
Originally Posted by noelex 77
I am realising I don't know as much about mast construction as I should. Any other recommendations for the perfect cruising mast for this yacht?
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I have been convinced that a 'properly built' carbon mast is better (but yes, rather more expensive) in all regards than aluminum (note: I consulted to southern spars for a while, and was CEO of a niche extreme modulus carbon pre-preg company). BUT the builders mostly don't understand the cruising application and many actually don't really understand carbon construction all that well.
regarding aluminum - I would suggest there are two common 'actionable/avoidable' problem points - the gooseneck/vang fittings, and all the stainless machine screws. You just can't do much to stop them from simply messing up something like a compression fitting.
I am guessing you have well formed opinions on the common design debates . . . . trysail tracks, checkstays/jumpers, reefing details, etc.
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18-06-2015, 08:33
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#292
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Moderator
Join Date: Mar 2009
Location: Denmark (Winter), Helsinki (Summer); Cruising the Baltic Sea this year!
Boat: Cutter-Rigged Moody 54
Posts: 33,750
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Re: Bestevaer 49ST
Quote:
Originally Posted by Seaworthy Lass
Thanks for the info. It is great to have a comparison.
Is that 14 mm Dyform that you have? And is the 23m mast height from deck or total height?
Our sail area will be:
Main: 66.5 m2
Yankee: 49.2 m2
SWL
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Ah, yes, from deck, and my sail area is more than that. That explains it.
My standing rigging is stainless wire, not dyform.
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18-06-2015, 08:36
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#293
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Moderator
Join Date: Mar 2009
Location: Denmark (Winter), Helsinki (Summer); Cruising the Baltic Sea this year!
Boat: Cutter-Rigged Moody 54
Posts: 33,750
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Re: Bestevaer 49ST
Quote:
Originally Posted by estarzinger
. . ..
I am guessing you have well formed opinions on the common design debates . . . . trysail tracks, checkstays/jumpers, reefing details, etc.
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We discussed jumpers earlier in the thread -- something I wish I had.
What is your view of them? Do they work?
As to trisail tracks -- Selden masts come with them as standard.
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18-06-2015, 09:35
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#294
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Moderator
Join Date: Oct 2008
Boat: Bestevaer 49
Posts: 16,151
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Re: Bestevaer 49ST
Quote:
Originally Posted by Dockhead
Ah, yes, from deck, and my sail area is more than that. That explains it.
My standing rigging is stainless wire, not dyform.
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The difference in breaking strength of Dyform compared to conventional SS wire rigging is substantial:
10mm: 9770 vs 7250 kg
12mm: 14400 vs 10400 kg
(14mm: 14100 kg for wire)
__________________
SWL (enthusiastic amateur)
"To me the simple act of tying a knot is an adventure in unlimited space." Clifford Ashley
"The cure for anything is salt water: sweat, tears or the sea." Isak Dinesen
Unveiling Bullseye strops for low friction rings
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18-06-2015, 09:58
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#295
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Moderator
Join Date: Mar 2009
Location: Denmark (Winter), Helsinki (Summer); Cruising the Baltic Sea this year!
Boat: Cutter-Rigged Moody 54
Posts: 33,750
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Re: Bestevaer 49ST
Quote:
Originally Posted by Seaworthy Lass
The difference in breaking strength of Dyform compared to conventional SS wire rigging is substantial:
10mm: 9770 vs 7250 kg
12mm: 14400 vs 10400 kg
(14mm: 14100 kg for wire)
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Cool, so less windage.
Any downside?
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18-06-2015, 10:10
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#296
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Moderator
Join Date: Oct 2008
Boat: Bestevaer 49
Posts: 16,151
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Re: Bestevaer 49ST
Quote:
Originally Posted by Dockhead
Cool, so less windage.
Any downside?
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Cost .
__________________
SWL (enthusiastic amateur)
"To me the simple act of tying a knot is an adventure in unlimited space." Clifford Ashley
"The cure for anything is salt water: sweat, tears or the sea." Isak Dinesen
Unveiling Bullseye strops for low friction rings
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18-06-2015, 10:14
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#297
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Senior Cruiser
Join Date: Aug 2009
Posts: 4,033
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Re: Bestevaer 49ST
Quote:
Originally Posted by Dockhead
We discussed jumpers earlier in the thread -- something I wish I had.
What is your view of them? Do they work?
As to trisail tracks -- Selden masts come with them as standard.
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yes, they 'work'. In fact I believe they are not 'popular' because they work so well that the various racing rules penalize them.
The only drawback I have seen to them is that they can restrict how closely a masthead code zero or similar sail) can be sheeted in.
my personal favorite 'solution' for trysail track and mainsail car is the harken switch track ( Harken). It allows a low stack height, convenient trysail with the minimum number of extra machine screws/holes, and high reliability.
We had dyform on Hawk . . . very nice . . . .only downside is you need 'special' fittings/cones for the terminals (unless you are using swaged, which I don't much like) and they have a minor increase in chafe potential.
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18-06-2015, 10:30
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#298
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Registered User
Join Date: Mar 2010
Location: Annapolis MD
Boat: Building a Max Cruise 44 hybrid electric cat
Posts: 3,194
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Re: Bestevaer 49ST
I have photos the helicopter boat's carbon boom snapped in half when in Las Palams if you'd like. Might want to find the details on why the Seldon boom snapped if you do go carbon instead of aluminum.
Matt
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18-06-2015, 12:15
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#299
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Moderator
Join Date: Oct 2008
Boat: Bestevaer 49
Posts: 16,151
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Re: Bestevaer 49ST
Quote:
Originally Posted by funjohnson
I have photos the helicopter boat's carbon boom snapped in half when in Las Palams if you'd like. Might want to find the details on why the Seldon boom snapped if you do go carbon instead of aluminum.
Matt
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That would be very interesting to see.
Failure modes are always instructive.
SWL
__________________
SWL (enthusiastic amateur)
"To me the simple act of tying a knot is an adventure in unlimited space." Clifford Ashley
"The cure for anything is salt water: sweat, tears or the sea." Isak Dinesen
Unveiling Bullseye strops for low friction rings
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18-06-2015, 12:33
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#300
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Registered User
Join Date: Jan 2014
Posts: 1,829
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Re: Bestevaer 49ST
This is one of the best threads I have read on CF.
I would repeat the recommendation to read the Dashew's boating encyclopedia book. It is loaded with information including information on rudders, in spades, pun intended.
Pretty sure I had to order the Dashew book from their website, it was expensive, but well worth the money. The book also has a section of building a boat that discusses, contracts, specifications, loans, etc.
Also, John Rousmaniere Desirable and Undesirable Characteristics of the Offshore Yachts, http://www.amazon.com/gp/product/B00...ilpage_o05_s00, has quite a few suggestions for boating details.
Both books have specifications and design details for dorades but SWL's, NL77's, and Evan's arguments AGAINST dorades are danged interesting. NOT having dorades would really clear up the deck...
I have not finished Evans book, Amazon.com: Singlehanded Sailing: Thoughts, Tips, Techniques & Tactics eBook: Andrew Evans: Kindle Store Andrew Evans book that is, on single handed sailing, but it does have some ideas that might be worth while to read.
Later,
Dan
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