Shocked by hull material catamaran

[chala]

Originally Posted by jimbunyard

Hardly the fault of the designer

Apparently at that time, an over use of the hydraulic backstay adjuster.

[SVNeko]

Originally Posted by Just Another Sa

It is infused with vinylester resin.
I don't know what surface paint is on it or not, but nothing prevents the buyer to add any protective paint he/she feels should be there before antifouling.

I doubt very much Lagoons are built with vinylester resin - I didn't even think they were infused. Even Outremers do not use all vinylester.

[yeloya]

Originally Posted by SVNeko

I doubt very much Lagoons are built with vinylester resin - I didn't even think they were infused. Even Outremers do not use all vinylester.

Agree on Lagoon and FP, disagree on Outremer and Catana..

[SVNeko]

Originally Posted by yeloya

Agree on Lagoon and FP, disagree on Outremer and Catana..

From what I know, which usually aint much, Outremers are poly resin with vinylester gelcoat. Relevant to this thread, I believe they have single skins below the waterline, which seems to be the way the French do it.

[44'cruisingcat]

Originally Posted by Redreuben

If it doesn't break it's too heavy,
If it breaks it was too light.

So we are now at the point where owners after driving down the European quality to a Chinese price, now want their floating Condos to be idiot proof so they can survive reef groundings ?

No, it seems the "condo" owners are happy with their boats as they are.

It's the owners of the heavily built "reef crushers", who think 10 foot think fibreglass should be the MINIMUM, who are telling them they're wrong.

[Just Another Sa]

Originally Posted by SVNeko

I doubt very much Lagoons are built with vinylester resin - I didn't even think they were infused. Even Outremers do not use all vinylester.

There you go:
Discover the technical choices for Lagoon catamarans

Structure

The infusion-moulding technique enables us not only to optimize the proportion of resin in the fibreglass (comparable to the pre-impregnated technique), but also to improve the bonding properties of the composite. The isolation of each balsa square by mechanical ties between the inner and outer skins improves the quality and reliability of the structure, and saves weight too. The systematic use of a very high-quality anti-osmotic resin ensures durability for all Lagoon catamarans.

and
Construction of Lagoon

Lagoon catamarans are built on two sites:


Belleville sur Vie, in the Vendée region

This factory, one of the latest generation of Groupe Bénéteau production sites, is totally devoted to the construction of Lagoon catamarans ranging from 38 to 45 feet in length.

With its computer-controlled equipment, infusion-moulding facilities, advanced mechanical, electrical and plumbing installation processes, and pool for testing the boats systems , the Belleville factory sums up the globally acknowledged technical expertise of the Groupe Bénéteau.

[minaret]

Originally Posted by Just Another Sa

There you go:
Discover the technical choices for Lagoon catamarans

and
Construction of Lagoon

How is infusion going to provide more control over resin ratio than pre-preg? Pre-preg in my experience provides by far the most control over this crucial factor. Hand laminated vacuum bagging second. Then very high quality hand lam by experienced crew, and then infusion. The only thing which provides less control over resin ratio in every portion of a large part is a chopper gun, IMHO. I've done a lot of high end bagging and infusion, started doing infusion on a production factory floor in '95,very early for that process. Parts with complex geometry are very difficult to create with the same resin ratio over the entire part, hydraulic lock at radii often creates areas which end up surprisingly rich. No gauging in most infusion set ups either, unlike in high end bagging. Only way to tell how much vacuum you are pulling in different areas of the bag is pinch test. This is fine for core bagging but insufficient for laminate, IMHO. Typical reliance of the advertisers on the consumer's ignorance of the technical process. I regularly do field burn tests of my own laminates, would love to do some on Lagoon samples; PM me to send one if you have it and would like to know for sure what the resin ratio in the layup is.

[noelex 77]

Originally Posted by SVNeko

From what I know, which usually aint much, Outremers are poly resin with vinylester gelcoat. Relevant to this thread, I believe they have single skins below the waterline, which seems to be the way the French do it.

Outremer are an interesting case. I agree, the hull underwater seems to be solid, not cored glass. In my view this is an excelent choice for a cruising boat but a rather surprising for a lightweight high performance cat.

If they are using as you suggest what seems to me a very basic structure of polyester resin with vinylester gelcoat, and solid glass underwater how are they producing lightweight boats?

It would be interesting to hear details of the layup and coctruction methods used. Do they perhaps use epoxy or at least vinyester rather than polyester resins? Does anyone know?

[smj]

Originally Posted by noelex 77

Outremer are an interesting case. I agree, the hull underwater seems to be solid, not cored glass. In my view this is an excelent choice for a cruising boat but a rather surprising for a lightweight high performance cat.



If they are using as you suggest what seems to me a very basic structure of polyester resin with vinylester gelcoat, and solid glass underwater how are they producing lightweight boats?



It would be interesting to hear details of the layup and coctruction methods used. Do they perhaps use epoxy or at least vinyester rather than polyester resins? Does anyone know?

The older Outremer's had solid glass hulls, no core whatsoever, and were still a great performance boat. I'm talking below as well as above waterline.

[44'cruisingcat]

Originally Posted by noelex 77

Outremer are an interesting case. I agree, the hull underwater seems to be solid, not cored glass. In my view this is an excelent choice for a cruising boat but a rather surprising for a lightweight high performance cat.

If they are using as you suggest what seems to me a very basic structure of polyester resin with vinylester gelcoat, and solid glass underwater how are they producing lightweight boats?

They have comparatively small accommodation for their length, and even then, they're not (IMO) particularly light boats.

[PaulinOz]

If you do a wet layup then bag and completely seal and pull the correct vacuum the resin is curing as you work and if difficulties occur in the sealing the vacuum bag (and this does happen) may cause issues. Especially if you have just done a wet layup on a complete 50 foot long 30 foot wide pair of hulls and underwing, which is the size boat that the discussion started about. Not such a big issue on something the size of a single hull sea canoe for example.


In the vacuum infusion process the part to be made is layed up dry, then bagged and a vacuum pulled on the assembly. Once and only once the assembly is completely sealed and correct vacuum archived (All the infusion process I was involved in had ample gauging both mechanical or electronic not a lot of pinching going on) then the resin is infused into the assembly and cured. The manufacture in this process has total control of the amount of resin injected into any dry assembly.

Pre-preg is supplied by the manufacture of the composite fibers already infused with a Thermo/pressure set resin that needs to be kept cold prior to use and has a limited shelf life at higher ambient temperatures. Control of the resin qty is handed over to the supplier of the composite fiber material.

The vacuum bagging takes place within a heated and pressurized autoclave. This works very well for smaller assemblies and even for larger assemblies where there is way less cost restrictions, read Aero-Space industry etc . An autoclave capable of accepting an 50 x 30 x 5 foot assembly would cost at a guess (been out of Vacuum Industry now for 12 years) 10's of millions of dollars. There are some developments I believe with ambient temperature, while under vacuum curing pre-pregs but I do not know if these are even commercially available yet.

The other big advantage of infusion is with today's OH&S issues the vapors are contained within the bag then exhausted via the vacuum pumps to scrubbers.

[noelex 77]

Originally Posted by 44'cruisingcat

They have comparatively small accommodation for their length, and even then, they're not (IMO) particularly light boats.

That makes more sense given the construction teqniques (although there is not much detail that I can find)

[weavis]

Broadblue Catamarans.

Broadblue touts its line of boats as "true bluewater cruisers" and builds to Category A (Oceangoing) standards in the European Union. Below the waterline, the hulls are solid glass reinforced with Kevlar in loaded areas. Above the waterline, hulls and deck are balsa-cored laminates with marine-grade-plywood reinforcement at hardware locations.

These are not mass produced boats. They however are made with care and precision and properly. Im not always a lover of their interiors but did manage to fall in love totally with one of their larger vessels for lots of reasons.

https://www.youtube.com/watch?v=3Pem-4H1qg0

[Just Another Sa]

Originally Posted by 44'cruisingcat

They have comparatively small accommodation for their length, and even then, they're not (IMO) particularly light boats.

That, and more internal stiffeners than cored hulls usually have, reducing required bending strength and stiffness, and thus thickness for hull laminates.
Lots of work to build those stiffeners increase prize to produce (labor cost) thus limiting how light is practicable. I don't think all their models (both current and past) use the same number of stiffeners, hence some are lighter than others, but none are anywhere near like MC2 60 in lightness.

[smj]

Different from all the other Broadblues as it is designed and built by Darren Newton, designer and builder of the Dazcats.