Jeanneau 40’+ sailboat hull/grid construction – is this correct?

[The Wolf]

As I understand (per other posts here on CF), the Jeanneau method of hull construction consists of a “… liner with grid of structural ribs that formed boxes: they cut out the bottoms of the boxes during assembly and then glue in the rib/box matrix to the hull just like a liner; after the grid is glued and cured they then go back and layup fiberglass over where the grid contacts on the hull.”

Is this correct?

Are the actual hulls all glass construction, or a balsa/foam core & glass?

How is any moisture/water that accumulates between the grid and the hull dispersed? Are there limber holes in the grid that drains down to the bilge? Or does moisture/water accumulate and, through the magic of evaporation, is not of concern?

Have Jeanneau owners ever had issues with moisture between the grid/hull?

I understand Bene just drops in a glued liner - no internal access to the hull unless you cut through the liner. X-Yachts have a heat-galvanized steel keel frame and an epoxy resin/glass/cellular foam sandwich. Oyster hulls seem to be of a solid composite/glass laminate using vinylester resin with stringers, bulkhead landings and floors formed over a non-structural, inert polyurethane foam.

Cheers!

[Jimbo2010]

the hulls are all glass on mine, built in '17.

they aren't glued the are fiberglassed to the hull, there are weep holes

I had a Bene before it had weep holes as well

What boat do you own?

[The Wolf]

Originally Posted by Jimbo2010

What boat do you own?

Currently boatless in Florida.

[Loredo]

They're not all created the same. Jeanneau has gone through a few different ways to build their boats over the years. At first it was a glued in liner, then they had a liner but with large cut-outs to access the the hull. I wouldn't know what changed in which year, you need to check out the boat you're interested in. I'm almost certain that until very recently all hulls were build in solid fiber glass. My previous Jeanneau had an issue with water between the liner and hull (water came from the shower sump) but is was an easy fix. Drill a small hole in the lowest part of that liner section and let the water drain out.

[coopec43]

I wasn't aware of this

"Since 1995, the Jeanneau shipyard has belonged to the Bénéteau Group, specialised in the construction of motorboats and sailboats, as well as prefabricated homes:

Sun Odyssey
"The hull is solid fiberglass, while the deck is balsa-cored, all with a ISO 9002 gelcoat. It has a masthead sloop rig with anodized aluminum spars, a raked stem"

[coopec43]

Well you won't have to worry if you hit a rock and lose your keel!

https://wavetrain.net/2010/12/24/cha...o-one-noticed/

[Pete7]

Originally Posted by Loredo

They're not all created the same. Jeanneau has gone through a few different ways to build their boats over the years.

Indeed, go back a few more years and some of the Jenneau's like the Sunrise 34/35 were built with layers of Kevlar in the bow and keel box areas. Nearly bought one but a total lack of paperwork explaining how it arrived in the UK and if import duty was paid including the uplift for the new engine, put and end to that one.

Pete

[The Wolf]

Originally Posted by coopec43

Well you won't have to worry if you hit a rock and lose your keel!

https://wavetrain.net/2010/12/24/cha...o-one-noticed/

Jeanneau's latest cost saving measure - direct to the customer!

[Loredo]

May I remind you about the Oyster that lost its keel and sunk without hitting anything?
Besides the fact that I have a hard time figuring out how ANY sailboat could possibly sail without its keel attached to where it belongs without capsizing... The Jeanneau got the crew back to port save and sound even without a keel.

Is the glass half full or half empty?

[Bowdrie]

Originally Posted by Loredo

Is the glass half full or half empty?

Neither, the engineers would say that the glass is twice as big, (or strong,) as it needs to be.

[Kd9truck]

Ok gonna warn you ahead of time, this may sound like I’m trying to sell my boat but that could not be further from the truth.

I own a 2010 SO 44i built at the Jeanneau factory in Vende’e France acquired in 2018.
The (i) in 44i was explained recently to me as”injection molded” With epoxy like a vacuum bag system for the exposed smooth inside surfaces of the cabin top, (no balsa).
I have the performance hull that draws 7.5 ft it is the 3 cabin 3 head “owners” version. The performance hull is all glass and kevlar no balsa.
The grid system is Kevlar reinforced 1 in thick, the hulls skin is Kevlar reinforced at the critical points ie: bow, stern, toe rail where the cabin/deck is glued and screwed together around the fairleads and winches. Inside in the bilge area, the Kevlar reinforced grid is glassed in fully with several layers Kevlar though out. The grid is carried up as high as the toe rail in many critical places and the hull skin is built out in this concern as well.

We’re the top meets the bottom ther is not 8 inches that does not have some form of SS attachment with backing plates toe rail screws, fairleads, stanchion bases all have access points for inspection and rebeding.

There are some small portions of the grid that have fiberglass pans that create a false bottom like a shower pan they all have drainage holes. All points of the vessel drain to the bilge when the vessel is at anchor.
I have drilled small 1/2 inch inspection holes in the grid and sent an articulating camera into them (I do this periodically) I have forced air though them to try to smell out and Oders, and they look as if the grid was set yesterday. There was a solid slightly bulging bead (where the grid meets the skin) of 5200 and it was clean and dry throughout.

I do all my own repairs as I have spent a life working with my hands in construction of many things i have had a look and regularly inspect and clean every nook and cranny. I occasionally spray Lysol 99% disinfectant into these voids because I can.

My vessel is dry and has seen no salt water intrusion, I have fitted water tight storage bins in the salon/galley recently as the space is so clean and accessible.

I can’t speak to other years or models but all the above I know to be true.
It’s light it’s fast it’s fun to sail for a day or make passage.

Oyster hulls are 4 inch’s thick throughout at least the 56s are.

Cheers

[boatpoker]

Originally Posted by Kd9truck

Ok gonna warn you ahead of time, this may sound like I’m trying to sell my boat but that could not be further from the truth.
I own a 2010 SO 44i built at the Jeanneau factory in Vende’e France acquired in 2018.
The (i) in 44i was explained recently to me as”injection molded” With epoxy like a vacuum bag system for the exposed smooth inside surfaces of the cabin top, (no balsa).

I'd suggest you have been misinformed. That model like all Jeanneau boats is built with polyester resin, not epoxy and the cabin trunk and decks are balsa cored just like every other Jeanneau. Only smaller molded parts are injection molded some hulls are resin infused but decks and cabin trunks are hand laid.
All easily confirmed with Jeanneau's own literature.

[Kd9truck]

Originally Posted by boatpoker

I'd suggest you have been misinformed. That model like all Jeanneau boats is built with polyester resin, not epoxy and the cabin trunk and decks are balsa cored just like every other Jeanneau. Only smaller molded parts are injection molded some hulls are resin infused but decks and cabin trunks are hand laid.
All easily confirmed with Jeanneau's own literature.

I in 2018 when I took ownership, I looked for what the (i) in 44i meant and to that point what constituted the term “performance version” as it pertains to the construction of the hull. I consulted a Jeanneau dealer and they could not offer printed info to these specific points, the verbal description I outlined in the content you challenged. I was told there was no balsa, I have found no balsa.

I can not speak to the literature you suggest, I can only defend my statement with my personal experience, for me it’s the proof of my dulled drill bit to several of my statements. I am familiar with what it looks like in drilled laminated fiberglass layers I have added hardware to the deck and to my hull I found no balsa wood shavings or dust

. Apologies on my lose use of the term epoxy I consider 2 part solutions under the epoxy umbrella,
Goggles def:
(Vinyl ester resin, or often just vinyl ester, is a resin produced by the esterification of an epoxy resin with acrylic or methacrylic acids.)

I have worked with Aramids in many different applications and in my life xperience. I use the property name Kevlar because it’s familiar to most people ,idk 100% that that is what my drill bits have hit but I know what it’s like to drill into an aramid and that is what I experienced.

I was sharing my own personal experience in the context of the construction of my vessel discovered buy me. If you have specific data to my model by all means please share, I am sure the OP would love the confirmation, I would love it as well.

All forums run on shared experiences, I offered my own personal experience with my boat. Just answering the OPs question. I would love a construction blue print of my specific model year, this is not a challenge to you or your integrity boatpoker just an ernest request.

[Loredo]

I have not found any balsa core in the deck either. At least not in the areas where I drilled holes for new hardware. What I did find as reinforcing under the sheet blocks for example is marine grade plywood embedded into the fiberglass. +/- an inch thick.

Look, a Jeanneau might not be the best of the best but if you compare the price of a new Jeanneau with a new "best of the best" boat you understand why there are so many Jeanneaus out there and not so many best of the best boats. The price is roughly like 1:4?