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21-01-2019, 05:56
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#16
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Registered User
Join Date: Apr 2013
Location: Md
Boat: 2013 FP Lipari 41
Posts: 1,298
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Re: Owner Built Boats and Builders
As suggested, there are several sources and lots of resources for home builders out there, as well as some great designers. I started building Bernd’s KD 122 Voyager until a health issue ceased the project. Your posts all have an angry inflection, and I’m not sure why.
You don’t want to build a boat, and you don’t want to buy a production boat so you only have one choice - create or buy a design that fits your needs and find somebody to build it. The fellow in Florida that has built the Wharrams seems open to one-offs and different projects.
Regards,
__________________
LeeV
Lipari 41
s/v AMERICAN HONEY
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21-01-2019, 08:41
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#17
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Registered User
Join Date: Dec 2014
Location: New Franklin, Ohio
Boat: Homebuilt schooner 64 ft. Sold.
Posts: 1,486
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Re: Owner Built Boats and Builders
Quote:
Originally Posted by LeeV
As suggested, there are several sources and lots of resources for home builders out there, as well as some great designers. I started building Bernd’s KD 122 Voyager until a health issue ceased the project. Your posts all have an angry inflection, and I’m not sure why.
You don’t want to build a boat, and you don’t want to buy a production boat so you only have one choice - create or buy a design that fits your needs and find somebody to build it. The fellow in Florida that has built the Wharrams seems open to one-offs and different projects.
Regards,
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“Angry inflection”, I like that. It sometime occurs when a person hears something that doesn’t agree with their own line of reasoning.
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21-01-2019, 08:44
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#18
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Registered User
Join Date: Jul 2008
Location: Satellite Beach, FL
Boat: Brewer 44' Steel
Posts: 394
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Re: Owner Built Boats and Builders
Join the Metal Boat Society. Exclusively dyi group but had ads for builders in steel and aluminum
Easier than wood or frp to make a hull. After that interior etc is all the same.
__________________
Russ
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21-01-2019, 08:44
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#19
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Senior Cruiser
Join Date: Jan 2010
Location: PORTUGAL
Posts: 30,586
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Re: Owner Built Boats and Builders
Quote:
Originally Posted by boatman61
I'm not playing a game.. theres a different set of mechanics (for immediate want of a better word) between a keeless V hull that relies on the hull for directional stability and a U hull which relies on a lump bolted on the bottom which increases weight and reduces payload.. not to mention draft Tiki 0.75,m.. Lagoon 380 1.15m.
On the Lagoons U the waterline runs near level to the decks beam width.. with the V hull its considerably inside the overall beam width by comparison.. you may not think this makes a difference but I do..
Also hobby horsing is largely down to poor loading/storage balance.. balance the load properly and it decreases significantly.
We will now return to conventional thinking..
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Dynamics.. thats the word I woz looking for..
Damn Als Hymer...
__________________
It was a dark and stormy night and the captain of the ship said.. "Hey Jim, spin us a yarn." and the yarn began like this.. "It was a dark and stormy night.."
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21-01-2019, 08:47
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#20
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Registered User
Join Date: Dec 2014
Location: New Franklin, Ohio
Boat: Homebuilt schooner 64 ft. Sold.
Posts: 1,486
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Re: Owner Built Boats and Builders
Quote:
Originally Posted by Russ
Join the Metal Boat Society. Exclusively dyi group but had ads for builders in steel and aluminum
Easier than wood or frp to make a hull. After that interior etc is all the same.
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Metal, even aluminum is too heavy for that sized multi- hull.
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21-01-2019, 08:56
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#21
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Registered User
Join Date: Apr 2013
Location: Md
Boat: 2013 FP Lipari 41
Posts: 1,298
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Re: Owner Built Boats and Builders
Quote:
Originally Posted by captlloyd
“Angry inflection”, I like that. It sometime occurs when a person hears something that doesn’t agree with their own line of reasoning.
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There was no disrespect intended; I was merely puzzled by the tone of displeasure, which by the way, was somewhat evident from the initial post.
__________________
LeeV
Lipari 41
s/v AMERICAN HONEY
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21-01-2019, 09:50
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#22
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Registered User
Join Date: May 2017
Posts: 810
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Re: Owner Built Boats and Builders
BM61:
This started out with a comment on how absurd a 30' catamaran with an 18' beam would look, not about stability dynamics. Here is an example. We can talk about length / beam ratio if you want, and I do understand that this should really be about LWL versus hull centerline beam..... But that's a different topic. Most of the older small factory built cats didn't even make the 50% figure using total beam. They also carried solid deck all the way forward, and took the bridge deck cabin too far forward. Fine for coastal sailing, but not something I'd want to be in a storm in the open ocean in.
No offense intended, but I totally fail to understand what you are trying to explain in the statement below, and would appreciate if you could rephrase it in a way that my simple mind can make sense of it:
"On the Lagoons U the waterline runs near level to the decks beam width.. with the V hull its considerably inside the overall beam width by comparison.. you may not think this makes a difference but I do.."
I'm well aware of the importance of proper weight distribution when it comes to hobby-horsing. I also know that a great deal of work has been done with hull shape to help with this. In any case, the same effect could be achieved with some "creative modification" The stern shape of the Wharram seems more appropriate for a proa. You could lop 3 or 4 feet off without losing much of value, except that the transom would be submerged, and that would be a drag liability.
H.W.
Quote:
Originally Posted by boatman61
I'm not playing a game.. theres a different set of mechanics (for immediate want of a better word) between a keeless V hull that relies on the hull for directional stability and a U hull which relies on a lump bolted on the bottom which increases weight and reduces payload.. not to mention draft Tiki 0.75,m.. Lagoon 380 1.15m.
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Quote:
Originally Posted by boatman61
On the Lagoons U the waterline runs near level to the decks beam width.. with the V hull its considerably inside the overall beam width by comparison.. you may not think this makes a difference but I do..
Also hobby horsing is largely down to poor loading/storage balance.. balance the load properly and it decreases significantly.
We will now return to conventional thinking..
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21-01-2019, 10:02
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#23
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Registered User
Join Date: May 2017
Posts: 810
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Re: Owner Built Boats and Builders
Quote:
Originally Posted by LeeV
There was no disrespect intended; I was merely puzzled by the tone of displeasure, which by the way, was somewhat evident from the initial post.
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I will be more careful about the use of caps..... I didn't intend it to be taken as yelling ;-) If there is displeasure on my part, it is based on the choices available in the size range I'm focusing on. There are indisputably good boats out there in that range, but in various respects they do not meet my criteria. Again, payload, beam, bridge deck too far forward, and poor clearance, too much windage, etc. Technology has come a long way, but at the same time, factories are building for the big money, and building charter boats, where it's a given that people will motor sail.
H.W.
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21-01-2019, 10:36
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#24
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Registered User
Join Date: Nov 2010
Location: Most of time on Boat, occassionally in Nevada
Boat: Custom Brewer Miami 45 45' - Quetzalcoatl
Posts: 97
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Re: Owner Built Boats and Builders
After building my 45' monohull using plans drawn by a renowned Naval Architect, I offer this advice. If you are primarily a sailor, then scrap this idea. Find a boat that you can tolerate and go sailing. If your interest is in building, construction and creating, then continue on. It took me eleven years from plans to departure and during that time I sure got lonely for the sea.
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21-01-2019, 10:36
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#25
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Registered User
Join Date: Apr 2013
Location: Md
Boat: 2013 FP Lipari 41
Posts: 1,298
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Re: Owner Built Boats and Builders
Quote:
Originally Posted by owly
I will be more careful about the use of caps..... I didn't intend it to be taken as yelling ;-) If there is displeasure on my part, it is based on the choices available in the size range I'm focusing on. There are indisputably good boats out there in that range, but in various respects they do not meet my criteria. Again, payload, beam, bridge deck too far forward, and poor clearance, too much windage, etc. Technology has come a long way, but at the same time, factories are building for the big money, and building charter boats, where it's a given that people will motor sail.
H.W.
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Not a problem. Regardless of our own situation that limits our selection, if I had the means I’d look at something like 44’CruisingCat’s boat, which I believe is a Bob Oram design. Brilliant boat. Take a look at his gallery.
I won’t even consider getting into complicated design features/theory discussions; way beyond me and they make my head hurt, much like Chemistry in h.s. and college. 🤪
__________________
LeeV
Lipari 41
s/v AMERICAN HONEY
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21-01-2019, 10:52
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#26
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Senior Cruiser
Join Date: Jan 2010
Location: PORTUGAL
Posts: 30,586
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Re: Owner Built Boats and Builders
Quote:
Originally Posted by owly
BM61:
This started out with a comment on how absurd a 30' catamaran with an 18' beam would look, not about stability dynamics. Here is an example. We can talk about length / beam ratio if you want, and I do understand that this should really be about LWL versus hull centerline beam..... But that's a different topic. Most of the older small factory built cats didn't even make the 50% figure using total beam. They also carried solid deck all the way forward, and took the bridge deck cabin too far forward. Fine for coastal sailing, but not something I'd want to be in a storm in the open ocean in.
No offense intended, but I totally fail to understand what you are trying to explain in the statement below, and would appreciate if you could rephrase it in a way that my simple mind can make sense of it:
"On the Lagoons U the waterline runs near level to the decks beam width.. with the V hull its considerably inside the overall beam width by comparison.. you may not think this makes a difference but I do.."
I'm well aware of the importance of proper weight distribution when it comes to hobby-horsing. I also know that a great deal of work has been done with hull shape to help with this. In any case, the same effect could be achieved with some "creative modification" The stern shape of the Wharram seems more appropriate for a proa. You could lop 3 or 4 feet off without losing much of value, except that the transom would be submerged, and that would be a drag liability.
H.W.
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The stern shape of the Tiki to my mind aids her in that it cuts through the water better..
My 21ftr could make 11kts over the ground in a decent breeze and my 26 made 17kts, no surfing involved in a F7 with full sail.
Another beniefit is they can be sailed in reverse, just head into wind, hold her in irons and she'll go into reverse gear.. very useful when engineless and sailing through mooring fields where 3 point turns are needed on occasion.
Regarding your comment about early production cats like Iroquois, Bobcats etc.. yes they were designed with narrower beams.. as a result were prone to capsize giving cats their bad name and leading to various ideas mounted on the top of mast to stop complete flips and aid righting..
Then they clicked.. the bulb lit and they follwed Wharrams lead to wider beams and lower aspect rigs for cruising.
As to my reasoning on the difference between a U and V hull.. if you cant see my reasoning from before I doubt I can make you see it now..
A common failure of mine..
__________________
It was a dark and stormy night and the captain of the ship said.. "Hey Jim, spin us a yarn." and the yarn began like this.. "It was a dark and stormy night.."
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21-01-2019, 11:41
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#27
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Registered User
Join Date: May 2017
Posts: 810
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Re: Owner Built Boats and Builders
As to my reasoning on the difference between a U and V hull.. if you cant see my reasoning from before I doubt I can make you see it now..
A common failure of mine.. [/QUOTE]
It was a communication problem I think.... I've read and reread those words.... and I'm far from dense. I simply could not figure out what you were trying to say. Perhaps someone else could clarify it for me.
I take your point about sailing in reverse, however cats with transoms do not normally drag the transom unless overloaded, and we know nobody overloads their cat ;-) Thus they should sail in reverse also. I've been an admirer of Rob Denney's innovative Harry Proa designs with their fore and aft rudders. I can see significant benefits to be gained from this on an ordinary catamaran.... for for leeway control, rapid turning for tacking, and for backing up.
H.W.
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21-01-2019, 11:55
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#28
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Registered User
Join Date: Jan 2017
Location: On the boat!
Boat: Moody 42 CC ketch
Posts: 71
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Re: Owner Built Boats and Builders
You might be interested in a friends blog - ‘Gleda’, a wharram Cat.
Website ‘ thegledaproject.com’.
Actually sailed it.
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21-01-2019, 15:02
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#29
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Registered User
Join Date: Dec 2014
Posts: 687
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Re: Owner Built Boats and Builders
Actually I am no boat designer but I have heard so many times that hobby horsing is largely a consequence of having similar bow and stern shapes. It's a bit like a see-saw with springs under both ends of the plank. If the loading and springs are the same at both ends, then expect resonance with an inducing wave pattern. I understand that this was an issue with lots of earlier catamarans (and monohulls as well). The changes to wider aft sections and/or bulbous bows were partly attempts to modify this feature. I guess that designers thought that to exceed the normal hull speed constraint of conventional displacement hulls then a very clean water/hull departure with minimum water acceleration producing a minimum stern wave was a good idea. Not to mention the fact that most Wharram cats were home built and simplicity of construction was a big issue. I am also sure that poor loading won't help, but the hull shape can't easily be modified once the boat hits the water. It is obviously a complex matter involving surface area minimization and other issues, but I believe that most designers juggle the features so their product hits the market place intended.
However, it's good to see someone exploring the issues for their own potential home project.
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21-01-2019, 15:20
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#30
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Registered User
Join Date: Feb 2010
Location: USA , NC
Boat: Catalina ??? To be decided
Posts: 15
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Re: Owner Built Boats and Builders
I did build my own boat , a Rival 41. Hull and deck built by Rival Bowman to Lloyd’s hull construction certificate.
This is very important for a home builder or home fitter outer .
To start with a recognised certified hull .
You are going to be putting a great deal of time and money into the project , you must safeguard your investment.
It took me 7 years , start to launch , working every minute I could .
All I can say is , you must be crazy to even think of doing this . I was . Would do it again NO .
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