The Evolution of "Condomarans"

[Bulawayo]

Hi Polux, I cannot disagree with what you are saying. Bonding is used globally as you have already pointed out - and in some very critical applications including aircraft - successfully.
Its the way it is used that leads to failures and unfortunately this where boat builders can fail miserably. I think some people were not comprehending what you wrote.
Due to failures it is probable that many people shall lay their faith in more traditional methods.
However, I keep reading of tabbing but my understanding of tabbing, learnt at several major manufacturers yards many moons ago, is the application of a small number of glassed on patches to position major items prior to the act of fibre glassing them in. If someone endorses or promotes that their bulkheads are only 'tabbed in' I would not be too comfortable on that boat.

Originally Posted by Polux

Let's cut the crap: Bonded can be superior to tabing and it all depends how it is made and materials used and it is not only a question of price. What is important is the way it is done and the materials used.

It is not only a question of price, not only entry price boats use bonding and even American quality boat builders use bonding agents to bond bulkheads for the hull even if they building methods are generally more conservative. For instance

Alerion: Structured Bulkheads: Marine grade plywood bulkheads bonded to hull and deck
http://www.alerionyachts.com/wp-cont...ist-1.1.14.pdf

C&C, older ones: A structural grid and hull pan are bonded to the hull, and the bulkheads and internal furnishings are bonded with adhesives developed for the aerospace industry.
new ones: Structural bulkheads bonded to hull and deck
Redline 41 - C&C Yachts
1999 C&C 121 Blue Hull Sail Boat For Sale - www.yachtworld.com

Jboats: GRP molded main structural bulkhead, bonded fore & aft on hull and deck.
Tech Specs

Tartan: Structural Bulkheads bonded to the hull
Tartan 4300 - Tartan Yachts - Page n° 2 - PDF Catalogues | Documentation | Boating Brochures

Regarding European ones, lots of them even if it is bad publicity talking about bonding agents because even if they are superior people tend to associate them with glue LOL

One of them is this to high end brand:

• The structural bulkheads are made from female moulds using same laminate sandwich system with core thickness of 20 mm. Bonded to hull and deck with Spabond 340 Epoxy Adhesive System (SP Systems).
• 2 x Forepeak bulkheads are watertight. The space in front of the forward bulkhead below the anchor well is filled with closed-cell PU foam.
• Longitudinal and transverse stiffeners going are built in solid laminate using Carbon/E-glass/Epoxy resin (prepreg vacuumbagging with curing at 85 degrees C) bonded to the hull and structural bulkheads with Spabond 340 Epoxy Adhesive System (SP Systems).

Bach Yachting - Shipman 50


Do you think they use bonding agents not because they are better but because they are cheaper?

I am not saying that all boats that use bonding agents use them properly I am saying that most accidents with bonding agents happen not because of their failure but because were improperly applied.

[Factor]

Originally Posted by zerompg

F Not to mention all the usable space on the solid foredeck.

No doubt that the solid foredeck (a very old idea that is reemerging) will soon be touted as the new highly safe and efficient way along with aft masts, headsail biased rigs, heavy boats, fat hulls, and low bridgedecks.

[robert sailor]

Originally Posted by Bulawayo

Hi Polux, I cannot disagree with what you are saying. Bonding is used globally as you have already pointed out - and in some very critical applications including aircraft - successfully.
Its the way it is used that leads to failures and unfortunately this where boat builders can fail miserably. I think some people were not comprehending what you wrote.
Due to failures it is probable that many people shall lay their faith in more traditional methods.
However, I keep reading of tabbing but my understanding of tabbing, learnt at several major manufacturers yards many moons ago, is the application of a small number of glassed on patches to position major items prior to the act of fibre glassing them in. If someone endorses or promotes that their bulkheads are only 'tabbed in' I would not be too comfortable on that boat.

Tabbing as a word doesn't really describe the job. Your description sounds more like what most people would expect from the word tabbing. Little bits of glass cloth here and there to hold the bulkhead in place.
In reality tabbing is a process that starts with a filet in the corner between the bulkhead and hull and a layer of glass from top to bottom of the bulkhead glassed in place. Then a wider piece of glass is added over top and then a wider piece over that etc. until the tabbing reaches out several inches on each side of the hull with each layer getting wider and wide. This makes for an extremely strong and yet flexible joint.
If your boat is a Valiant 44 the bulkheads are tabbed into place and its one tough boat you could sail anywhere. Tabbed bulkheads also mean that the boat will not be built with full liners. Cheers

[Cadence]

Originally Posted by robert sailor

Tabbing as a word doesn't really describe the job. Your description sounds more like what most people would expect from the word tabbing. Little bits of glass cloth here and there to hold the bulkhead in place.
In reality tabbing is a process that starts with a filet in the corner between the bulkhead and hull and a layer of glass from top to bottom of the bulkhead glassed in place. Then a wider piece of glass is added over top and then a wider piece over that etc. until the tabbing reaches out several inches on each side of the hull with each layer getting wider and wide. This makes for an extremely strong and yet flexible joint.
If your boat is a Valiant 44 the bulkheads are tabbed into place and its one tough boat you could sail anywhere. Tabbed bulkheads also mean that the boat will not be built with full liners. Cheers

I've seen tabbing used as just a glassing into place here an there with no more than FG tape. What you are describing is how it should be done. I would go with the first later extending the farthest and built up with layers with less width over a good fillet at the joint. Starting wide or narrow is probably a nit.

[robert sailor]

Originally Posted by Cadence

I've seen tabbing used as just a glassing into place here an there with no more than FG tape. What you are describing is how it should be done. I would go with the first later extending the farthest and built up with layers with less width over a good fillet at the joint. Starting wide or narrow is probably a nit.

OK here is a pic of what a proper tabbed bulkhead looks like.

[D&D]

G'day Andrew/retired chap!

Think the post we described as brilliant was meant to be very much tongue-in-cheek, aimed to bring smiles rather than be taken for anything substantive...or at least we sure took it that way...

Hope you and yours are all in good health & spirits?

[Skip JayR]

Originally Posted by cwjohm

Skip, you really need to get with the Cruisers forum naming methodology.

... and I thought its a mix of "flying object" like a Condor + scrambling around like a goanna (latin: "genus Varanus"). That was my first association I got.

Originally Posted by cwjohm

I hope this clears up the confusion.

Good I am out of that "cat thing business" now as I am more lurking around with Trimarans. :-)

P.S.: I was skipper professionally for the owner of a 15 meter Aluminium Catamaran (single built) during 2 seasons (with 10 berth: 2x double bed cabin + 2x double and single bed cabin). I suppose I misused this multihull and mixed up your definitions little bit as I paced around with >20 knots.

[StuM]

Originally Posted by Skip JayR

Does anybody know the origin of "Condomaran" ? When appeared this term first time in the scene of boating, yachting and sailing world ?

The oldest reference I could find with a quick google search is 1999
and it is used without explanation, so it must be a bit earlier than that.

https://groups.google.com/forum/#!ms...s/Oo4SAWzZqh0J

[Polux]

Originally Posted by Bulawayo

Hi Polux, I cannot disagree with what you are saying. Bonding is used globally as you have already pointed out - and in some very critical applications including aircraft - successfully.
Its the way it is used that leads to failures and unfortunately this where boat builders can fail miserably. I think some people were not comprehending what you wrote.
Due to failures it is probable that many people shall lay their faith in more traditional methods.
However, I keep reading of tabbing but my understanding of tabbing, learnt at several major manufacturers yards many moons ago, is the application of a small number of glassed on patches to position major items prior to the act of fibre glassing them in. If someone endorses or promotes that their bulkheads are only 'tabbed in' I would not be too comfortable on that boat.

I cannot agree more, except in what regards what you call tabbing, that if well made means to cover the junction with fiberglass as Robert had show in a photo.

Today the ones that make explicit on the boat propaganda that their bulkheads are tabbed do that for commercial reasons (because as you say bonding still looks suspicious to many).

Some high end brands use to fix bulkheads bonding agents and tabbing over it, being more the fiberglassing with vinylester to warranty them to be completely waterproof.

[Factor]

Originally Posted by D&D

G'day Andrew/retired chap!

Think the post we described as brilliant was meant to be very much tongue-in-cheek, aimed to bring smiles rather than be taken for anything substantive...or at least we sure took it that way...

Hope you and yours are all in good health & spirits?

Yeah I know, Chris and I have a different view on what constitutes Cruising and the necessary requirements.

As for me - have been spending the last few months in South America, mainly Chile and currently in Torres Del Paine national park in Patagonia. Simply stunning. Did go to the Alwoplast factory in Valdivia, they build, amongst other things, the Chris White Cats. Amazing quality of work in a very remote location. Also a stunning place.

[D&D]

Originally Posted by Factor

...have been spending the last few months in South America, mainly Chile and currently in Torres Del Paine national park in Patagonia. Simply stunning. Did go to the Alwoplast factory in Valdivia, they build, amongst other things, the Chris White Cats. Amazing quality of work in a very remote location. Also a stunning place.

Sounds beautiful...and a part of the world we are yet to explore, altho it's on that list! Enjoy!!

Also sounds a bit of a mixed work/pleasure thing? Are you actually a "retired chap"?!?

[GrahamHO]

Originally Posted by Bulawayo

Sadly too many cats are going this route to pander to the charter market. Look at Leopards with their trend of forward cockpits with a suspended hard top over them and then picture what shall happen when a big greenie sweeps over from forward, swiftly followed by his multitude of followers. If the 'lid' is not peeled off, then what happens to that nice big glass door? Or the several tons of water in the forward cockpit? As for raised helm positions.....that is another whole rant just waiting to happen.
The trouble is that this only supplying what the market demands.

Probably they are OK for the charter market where there are usually restrictions as to where they are allowed to be sailed / motored. Not for me even if I could afford one.
Plenty of other good designs....you could even have foils if you want. I'm not sure how they would cope with a "big greenie". Horses for courses.

[rabbi]

Originally Posted by robert sailor

OK here is a pic of what a proper tabbed bulkhead looks like.

Attachment 111397

Good to know that even my entry-level Mahe 36 has properly tabbed bulkheads. Some foam cored, some wood but all glassed into place.

[Cadence]

I don't think this was meant to slam all cats. Just maybe one with a house size reefer on the bridge deck. Probably nice for some, if they can afford it. I like my cold beer but don't think I can swing one. If I could I would probably be drinking cognac or not.


Just out of curiosity, I have seen no evaluation of Endeavour Cats? I had made friends with a couple that had an Endeavour Trawler Cat, over a beer. Impressive appointments for a 36 footer. Wondering about their sailing cats?

[downunder]

Originally Posted by Factor

Yeah I know, Chris and I have a different view on what constitutes Cruising and the necessary requirements.

As for me - have been spending the last few months in South America, mainly Chile and currently in Torres Del Paine national park in Patagonia. Simply stunning. Did go to the Alwoplast factory in Valdivia, they build, amongst other things, the Chris White Cats. Amazing quality of work in a very remote location. Also a stunning place.

Factor,

If you get the chance and visit Lima in Peru try and catch up with Giorgio Ballotta of Ballotta.

Have a 60ft Kelsall close to finish and about to start a Harryproa

Cheers