Reply
 
Thread Tools Search this Thread Display Modes
 
Old 01-21-2019, 09:05 PM   #41
Guru
 
BruceK's Avatar
 
City: Sydney
Vessel Name: Sojourn
Vessel Model: Integrity 386
Join Date: Oct 2011
Posts: 13,331
Because the boat fits most of our needs(except I can`t find space for solar panels),I have persisted with it, perhaps to perseverative error, but I have my eyes open. We`ve spent 3.5 hours going all through the boat. As David says, the riser raw water injection/turbos problem may be manageable, and certainly can be dealt with at survey, by tear down if necessary, as Sunchaser wisely suggested.
The hull construction is different, it`s permanent. A simple error with a thru hull can bring on a wet rotting core. And what if it developed osmosis? Against this, there doesn`t seem to be history of Beneteau hull failures, and as the video shows they are built to a program, not cobbled together in unpredictable conditions.
I`ve raised the 2 main issues, there are others which would not deter me. We both like it as a boat,but I`m having trouble pulling the trigger. In real estate(my short post retirement fun "career") a colleague would sometimes ask "Is there a price at which you would buy it"? That`s the question,sometimes the answer is "no",I`m very close to that. I may have a chat with the broker and see if he volunteers another price. He`s entitled to the courtesy of a " thank you but no thanks".
The boat has been for sale a while, hull may be why, though trawlers don`t sell so well in Sydney. Price is not far off a Riv 40 of similar age, they`re not giving it away. I`ve a feeling they`ve lost buyers before due to the hull construction,and they may well lose another.
__________________
BruceK
2005 Integrity 386 "Sojourn"
Sydney Australia
BruceK is offline   Reply With Quote
Old 01-21-2019, 09:12 PM   #42
Guru
 
BruceK's Avatar
 
City: Sydney
Vessel Name: Sojourn
Vessel Model: Integrity 386
Join Date: Oct 2011
Posts: 13,331
Quote:
Originally Posted by Ka_sea_ta View Post
.. As far as the ST goes the salon and galley layout on the ones we on weren't my cup of tea. But I've haven't heard or read anything about water intrusion issues in the hull either.
Beneteau should have followed the Clipper 40/Mariner 40 layout. The worst design aspect imo is 2 tiny adjacent bathrooms,one large one would be better. But in general, the design suited us. We figured to use one bathroom as head, the other as shower. Our IG separates the two completely.
__________________
BruceK
2005 Integrity 386 "Sojourn"
Sydney Australia
BruceK is offline   Reply With Quote
Old 01-21-2019, 09:55 PM   #43
Guru
 
Ka_sea_ta's Avatar
 
City: Puget Sound
Join Date: Jun 2016
Posts: 631
[QUOTE=

If you're buying or building a smaller "glass" in the water all the time yacht, stick with the herd in avoiding any chance of hull saturation - go solid FRP and do it well - makes sense to me.[/QUOTE]



I think you would be surprised at the number of in water boats that are cored below the waterline. Among them Viking, Cabo, Bayliner, Carver and Lindells just to name a few. The real problem with coring is two fold improper installation of thru hulls and failed bedding of penetrations above the waterline. Even our Defever suffered from delamination around the Windlass where the sealing to the hull failed. That is the reason to always have a boat surveyed
Ka_sea_ta is offline   Reply With Quote
Old 01-21-2019, 10:01 PM   #44
Member
 
Reformed-sailor's Avatar
 
City: Bicoastal
Join Date: Jan 2019
Posts: 22
Benneteau isn’t following the 1970s era techniques. In fact one of the advantages of a large producer like this is they can optimize and use modern techniques and technology.
My understanding of their process:
- they are using vacuum bagged infusion
- the balsa is perforated to support resin take up.
- the balsa is pre-infused with a resin designed for this process
- the balsa appears to be saturated before its ever placed in the mold or under the vacuum bag
- I can’t imagine they don’t leave extra space around thru hull locations and probably use carbon fiber or Kevlar reinforcement when needed.

Boat tech does advance more slowly than some other areas but composite technology has been continuously evolving for over a century.

All general rules of thumb based on construction techniques should be specific to a time period when the problem happened, and we shouldn’t assume that manufacturers never update their technology.

Horror stories about 20+ year old boats seem inappropriate.
Reformed-sailor is offline   Reply With Quote
Old 01-22-2019, 12:07 AM   #45
Guru
 
City: Here
Join Date: Sep 2012
Posts: 2,940
Quote:
Originally Posted by Reformed-sailor View Post
- the balsa is perforated to support resin take up.

- the balsa is pre-infused with a resin designed for this process

- the balsa appears to be saturated before its ever placed in the mold or under the vacuum bag

- I can’t imagine they don’t leave extra space around thru hull locations and probably use carbon fiber or Kevlar reinforcement when needed.
1. The balsa is not perforated, it is kerfed.The purpose of the kerfs is that the sheets of balsa on scrim are flexible for forming in the mold. Even vacuum processes do not ensure all kerfs are filled. If all kerfs were filled as many mfg's have claimed, there would be no migration of moisture to adjacent kerfed blocks and we all know that happens frequently.

2.The balsa cannot be saturated. This would require evacuating the lignin which is about 40% of the balsa by weight and also filling all the cells which is not possible with any of the several current vacuum systems. Even if possible this would defeat the benefits of balsa altogether i.e. light weight and strength. Resin barely penetrates the end grain of balsa but does bond exceptionally well even better than it bonds to foam cores.

I've never seen a Beneteau with carbon fibre or Kevlar (which is added for abrasion resistence not strength as it is tough but too flexible).

I'm not a fan of balsa below the waterline but still like to keep the facts straight.
boatpoker is offline   Reply With Quote
Old 01-22-2019, 04:20 AM   #46
Member
 
Reformed-sailor's Avatar
 
City: Bicoastal
Join Date: Jan 2019
Posts: 22
Cored Hull Underwater

The video mentions they use other materials, besides fiberglass and balsa for strengthening. It’s not a kerf they showed, and elsewhere it has been claimed they are perforated.

Given that plastic foam is relatively inexpensive there must be some reason for choosing balsa instead. I don’t believe it is a cost saving measure these days.
Reformed-sailor is offline   Reply With Quote
Old 01-22-2019, 07:25 AM   #47
Guru
 
City: Here
Join Date: Sep 2012
Posts: 2,940
Quote:
Originally Posted by Reformed-sailor View Post
The video mentions they use other materials, besides fiberglass and balsa for strengthening. It’s not a kerf they showed, and elsewhere it has been claimed they are perforated.

Given that plastic foam is relatively inexpensive there must be some reason for choosing balsa instead. I don’t believe it is a cost saving measure these days.
They use balsa because resin bonds to it better than foam and it is stronger (when dry) than most available foam cores.

I just realized what you mean by perforated. There is a balsa core available with a one or two small holes punched through each square of kerfed balsa (a marginal bonding improvement).
boatpoker is offline   Reply With Quote
Old 01-22-2019, 07:52 AM   #48
Guru
 
Boat's Avatar
 
City: SchoolHouse Branch
Join Date: Jul 2018
Posts: 551
Intentional Oversimplification

Balsa cored boats are wood boats with some fiberglass on the outside. Been trying to change that view and can't. The thread about wood rot porn is not going away. You peel the fiberglass off one to do structural work and take the paint off the other.

Someone posted a link to a yacht survey website. Those cored boat articles on that site are eye-openers too.
Boat is offline   Reply With Quote
Old 01-22-2019, 09:16 AM   #49
Valued Technical Contributor
 
DavidM's Avatar
 
City: Litchfield, Ct
Join Date: Aug 2012
Posts: 6,785
Quote:
Originally Posted by Boat View Post
Balsa cored boats are wood boats with some fiberglass on the outside. Been trying to change that view and can't. The thread about wood rot porn is not going away. You peel the fiberglass off one to do structural work and take the paint off the other.

Someone posted a link to a yacht survey website. Those cored boat articles on that site are eye-openers too.

I couldn't disagree more with that viewpoint. Wood boats are structurally sound with or without paint or outside coatings. Balsa cored fiberglass is an engineered composite structure where each component interacts with the other to provide its structural strength. A balsa cored hull would fall apart without the fiberglass on the sides.


I don't know any work that requires you to "peel off the fiberglass to do structural work" on balsa cored hulls. You do have to recreate the three layers if the structure is compromised, usually by tapering back the fiberglass layers, laying in new core and glassing back the outside layers.


David
DavidM is offline   Reply With Quote
Old 01-22-2019, 09:40 AM   #50
Guru
 
Codger2's Avatar
 
City: San Diego
Vessel Name: Circuit Breaker
Vessel Model: 2021..22' Duffy Cuddy cabin
Join Date: Oct 2007
Posts: 6,691
Quote:
Originally Posted by Ka_sea_ta View Post
The hull is composed of a closed-cell foam core from deck to waterline. The underlying hull below the waterline is an end-grain balsa-cored superstructure.


seems strange you're so vehemently against coring
just sayin
Sorry I couldn't respond to this sooner but I had more pressing problems with a medical issue.

Hull specs are in paragraph 5 of the below link.

"just saying!"

Ocean Alexander 42 Altus Review - CLASSIC ECONOMICS by Kevin Falvey
Attached Thumbnails
OA Specs 2.png  
__________________
Done with diesel power boats! Have fallen in love with all electric!
Codger2 is offline   Reply With Quote
Old 01-22-2019, 09:59 AM   #51
Guru
 
BandB's Avatar
 
City: Fort Lauderdale. Florida, USA
Join Date: Jan 2014
Posts: 21,449
In my opinion it's not coring or not, it's the quality of coring. There are some of the finest boats on the market that have cored for decades with Airex and never had an issue. There are balsa cored boats with no problems. Coring or not would not by itself make my decision for me. I'd look at the builder's reputation and experience and all the other factors of the boat. All the issues I've heard of regarding Swift Trawlers and none of them have been regarding the coring. I'd definitely have a moisture check in survey and I'd be concerned about other things you've mentioned.

Now, as to you and this boat. Sounds to me like you posted thinking we'd discourage you from a purchase you're not comfortable with. I have one piece of advice, "When in doubt, don't." I can't discourage you because the coring doesn't bother me, but seems like enough other things have you concerned.

As to Pascoe, I dismiss him on this like I do on 90% of his reviews and comments. He had a mindset from decades before he was even born and no objectivity as far as boats that didn't fit it or new ideas of anything else.
BandB is offline   Reply With Quote
Old 01-22-2019, 10:02 AM   #52
Guru
 
City: gulf coast
Join Date: Jun 2014
Posts: 3,440
Quote:
Originally Posted by Ka_sea_ta View Post
I think you would be surprised at the number of in water boats that are cored below the waterline. Among them Viking, Cabo, Bayliner, Carver and Lindells just to name a few. The real problem with coring is two fold improper installation of thru hulls and failed bedding of penetrations above the waterline. Even our Defever suffered from delamination around the Windlass where the sealing to the hull failed. That is the reason to always have a boat surveyed
You paint with too broad a brush, just like Pascoe.

Not all boats by those or any makers were built the same. many , many changes happened over the years including complete takeover of the company. My Carver for example had a solid bottom.
bayview is offline   Reply With Quote
Old 01-22-2019, 10:24 AM   #53
Guru
 
City: Northport
Join Date: Aug 2015
Posts: 2,046
I have owned boats with Balsa core although not below the water line.
I have owned boats with closed cell foam core as well.

The 3 boats with balsa coring (not below water line) all had some spots which eventually were compromised with water. The balsa in those area turns to something the consistency of "oatmeal' ….it has no strength,, the affected area expands quickly , it is harder tp repair correctly.
With the foam core problems I have seen (which are rare) there is a much smaller affected area, strength is not as easily compromised and they are more easily repaired correctly.
My experience only - I cannot say what I have not seen.
smitty477 is offline   Reply With Quote
Old 01-22-2019, 10:50 AM   #54
Guru
 
Ka_sea_ta's Avatar
 
City: Puget Sound
Join Date: Jun 2016
Posts: 631
Quote:
Originally Posted by bayview View Post
You paint with too broad a brush, just like Pascoe.

Not all boats by those or any makers were built the same. many , many changes happened over the years including complete takeover of the company. My Carver for example had a solid bottom.



Sorry I didn't mean to get anyone's knickers in a knot. What I should have said is these builders have built certain models of boats using coring as a construction method.... My apologies to those that may have found fault with my generalized statement. And please don't compare me to Pascoe, he was much more knowledgeable about boats then I ever will be
Ka_sea_ta is offline   Reply With Quote
Old 01-22-2019, 11:32 AM   #55
Moderator Emeritus
 
Comodave's Avatar
 
City: Au Gres, MI
Vessel Name: Black Dog
Vessel Model: Formula 41PC
Join Date: Jul 2015
Posts: 21,189
I would assume that Beneteau would know how to properly lay up a cored hull. My concern would be who has done what with the hull since new and has there been any damage to the hull inside or out and how was it repaired? If there is one place for water to get in it may run a long way and then you have balsa mush.
Comodave is online now   Reply With Quote
Old 01-22-2019, 12:47 PM   #56
Valued Technical Contributor
 
DavidM's Avatar
 
City: Litchfield, Ct
Join Date: Aug 2012
Posts: 6,785
Quote:
Originally Posted by Comodave View Post
I would assume that Beneteau would know how to properly lay up a cored hull. My concern would be who has done what with the hull since new and has there been any damage to the hull inside or out and how was it repaired? If there is one place for water to get in it may run a long way and then you have balsa mush.

Well, they sure don't know how to design and install an exhaust system, so I would be suspicious. But I think that you can see if there is solid fiberglass around the thru hull penetrations- it is thinner than the surrounding cored hull. If I could check all thru hull penetrations and see solid glass I would be confident it was built right.


But you are also correct that any non factory installations would be suspect. Those wouldn't be easy to check as any core dug out around penetrations and filled with thickened epoxy would be impossible to see without removing the thru hull.


A moisture meter reading around those new penetrations might give you a good clue though.



David
DavidM is offline   Reply With Quote
Old 01-22-2019, 01:19 PM   #57
Guru
 
Boat's Avatar
 
City: SchoolHouse Branch
Join Date: Jul 2018
Posts: 551
Quote:
Originally Posted by Boat View Post
Balsa cored boats are wood boats with some fiberglass on the outside. Been trying to change that view and can't. The thread about wood rot porn is not going away. You peel the fiberglass off one to do structural work and take the paint off the other.

Someone posted a link to a yacht survey website. Those cored boat articles on that site are eye-openers too.
I said this is an intentional oversimplification.

For the same reasons people fear wood boats they should also fear cored boats.

The initial designs and quality control are important and equally important are any modifications and maintenance.

I'll venture a step further out on this limb. Foam cored boats should feared for voids created by economy of materials. If there is room for water to take up space in a hull, it will. Problems ensue. Stuff they use to fill the voids is sometimes just stuffing. All it does is take up space, until it doesn't.

Foam tears. Strap me down to piece of foam and I'm not feeling very secure.

All this being said I have trusted boats and aircraft with foam cores, wood, metal. It's all good with reservations. I think a generation of Corvettes had a foam core floor. (it's wood, I checked)

Anything humans build, nature can dismantle. "History shows again and again how nature points out the folly of man."
Boat is offline   Reply With Quote
Old 01-22-2019, 02:05 PM   #58
Moderator Emeritus
 
Comodave's Avatar
 
City: Au Gres, MI
Vessel Name: Black Dog
Vessel Model: Formula 41PC
Join Date: Jul 2015
Posts: 21,189
Well, in looking at the question in general, what are the benefits of a cored hull? The main benefit as I see it is weight savings. I have a “trawler”. I really don’t care that much about weight. But I do care about whether my hull comes apart. So put me in the camp of rather having a solid core, unless a boat I just really really have to have comes along, then I might roll the dice...
Comodave is online now   Reply With Quote
Old 01-22-2019, 02:27 PM   #59
Veteran Member
 
CptnPete's Avatar
 
City: Scituate
Vessel Model: Morton & Hersloff Webbers Cove 40
Join Date: Jun 2018
Posts: 48
I had a sailboat i bought new that had balsa coring below the water line. It was made by a reputable builder known for their glass building technology, but not necessarily their cored glass technology.

For 25 years I had the boat hauled and transported by truck 50 miles for winter storage on stands and blocks in my yard. Most of the weight was on the keel.

It had solid glass for all factory thru hulls, but the dealer installed electronics through the cored part of the hull.

When i sold it the only moisture noted by the surveyor was where the dealer put the thru hull.

That said, i always wondered/worried about damage from transport and storage, although never noticed any.

And it was not a boat i would have ever wanted to leave in year round.

I followed that with a sailboat with foam coring above the water line. It felt more robust and rock solid.

Give me thick solid glass and i think i sleep better.
CptnPete is offline   Reply With Quote
Old 01-22-2019, 03:02 PM   #60
Member
 
Reformed-sailor's Avatar
 
City: Bicoastal
Join Date: Jan 2019
Posts: 22
Cored Hull Underwater

Quote:
Originally Posted by CptnPete View Post
Give me thick solid glass and i think i sleep better.
I would too.

I’m glad you mentioned sleep quality, because that’s what this is really all about. It’s psychological. There are so many variables, not just in production practices but in the experience the boat has had.

The fact water damage can be hidden in fiberglass emphasizes the psychological factor here.

The only solution is to switch to all aluminum hulls. This way we can watch the zincs and know for sure. Plus it’s lighter and stronger.
Reformed-sailor is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Trawler Port Captains
Port Captains are TF volunteers who can serve as local guides or assist with local arrangements and information. Search below to locate Port Captains near your destination. To learn more about this program read here: TF Port Captain Program





All times are GMT -5. The time now is 08:42 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012