Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 14-12-2014, 17:53   #271
Registered User

Join Date: Jun 2014
Location: San Diego, CA
Boat: Beneteau Oceanis 38
Posts: 563
Re: Beneteau 38

I'm not saying it's superior, I'm saying its stiffer at the same strength in GRP. Whether or not that's a good thing depends on a lot of design variables.

In carbon fiber, vacuum bagging is mandatory because trapped gasses, excess resin, and improper wet-out dramatically reduce the strength properties of the resulting laminate. In GRP the differences are far less dramatic and it's easy to compensate for with just an extra layer.

The downside of stiffness is lower resistance to impact damage.

Vacuum bagging also allows for more consistency in mechanical properties because the resin to glass ratio can be precisely controlled.

Open-mold Is cheaper and its stiffer. Neither of those necessarily imply that it's better.

Think of it as the difference between a softwood and a hardwood of the same weight but different thickness. The hardwood will take more flex before splintering, and the softwood is stiffer but will break suddenly. Which is better depends on your application.

In the case of these large, semi-frameless (there are moulded-in ribs under the deck) boats whose hulls provide the structural integrity, stiffness is critical.



Sent from my iPhone using Cruisers Sailing Forum
__________________

__________________
mstrebe is offline   Reply With Quote
Old 14-12-2014, 18:09   #272
Registered User
 
Polux's Avatar

Join Date: Nov 2011
Location: Portugal/Med
Boat: Comet 41s
Posts: 5,757
Re: Beneteau 38

Quote:
Originally Posted by mstrebe View Post
I'm not saying it's superior, I'm saying its stiffer at the same strength in GRP. Whether or not that's a good thing depends on a lot of design variables.

In carbon fiber, vacuum bagging is mandatory because trapped gasses, excess resin, and improper wet-out dramatically reduce the strength properties of the resulting laminate. In GRP the differences are far less dramatic and it's easy to compensate for with just an extra layer.

The downside of stiffness is lower resistance to impact damage.

Vacuum bagging also allows for more consistency in mechanical properties because the resin to glass ratio can be precisely controlled.

Open-mold Is cheaper and its stiffer. Neither of those necessarily imply that it's better.

Think of it as the difference between a softwood and a hardwood of the same weight but different thickness. The hardwood will take more flex before splintering, and the softwood is stiffer but will break suddenly. Which is better depends on your application.

In the case of these large, semi-frameless (there are moulded-in ribs under the deck) boats whose hulls provide the structural integrity, stiffness is critical.

...
Ok! Nice explanation The stiffness as the lesser flexibility are linked to the bigger resin content, if I understand correctly.
__________________

Polux is offline   Reply With Quote
Old 14-12-2014, 18:10   #273
Registered User

Join Date: Jun 2014
Location: San Diego, CA
Boat: Beneteau Oceanis 38
Posts: 563
Re: Beneteau 38

And trapped gas bubbles as well, acting as a "foam" in the resin.


Sent from my iPhone using Cruisers Sailing Forum
__________________
mstrebe is offline   Reply With Quote
Old 14-12-2014, 21:19   #274
Registered User
 
RKsailsolo's Avatar

Join Date: Mar 2013
Location: St Paul, US
Boat: Jeanneau 349 2015
Posts: 706
Beneteau 38

Controlling the Resin to glass ratio and void removal IS the object of vacuum bagging a polyester laminate. I don't see how that process necessarily reduces laminate thickness by almost one third. Higher resin to glass ratios makes the laminate brittle and less flexible. The end result of a bagged laminate vs the same layup schedule in open molded contact layup is that the bagged laminate will have a higher glass to resin content making that laminate more resistant to fracture.

I see this as a decision to ensure the engineered specs are maintained vs. a cost savings method. It's easier to hire a semi skilled chopper gun operator and layup crew to slam in the layup versus going through the effort to bag it.
__________________
RKsailsolo is offline   Reply With Quote
Old 15-12-2014, 09:03   #275
Registered User

Join Date: Jun 2014
Location: San Diego, CA
Boat: Beneteau Oceanis 38
Posts: 563
Re: Beneteau 38

Quote:
Originally Posted by RKsailsolo View Post
Controlling the Resin to glass ratio and void removal IS the object of vacuum bagging a polyester laminate. I don't see how that process necessarily reduces laminate thickness by almost one third. Higher resin to glass ratios makes the laminate brittle and less flexible. The end result of a bagged laminate vs the same layup schedule in open molded contact layup is that the bagged laminate will have a higher glass to resin content making that laminate more resistant to fracture.

I see this as a decision to ensure the engineered specs are maintained vs. a cost savings method. It's easier to hire a semi skilled chopper gun operator and layup crew to slam in the layup versus going through the effort to bag it.
You are saying exactly the same thing I'm saying.

Vacuum bagging creates external pressure equal to atmospheric pressure that puts the laminate under constant compression as it sets. This forces the glass fibers to pack together more tightly than they would under no pressure, thus forcing out excess resin and trapped bubbles of gas. Because the glass is more tightly packed, considerably less resin remains, and so the glass to resin ratio is much higher. The hull consists of more glass than resin, and therefore takes on more of the material properties of glass than resin which endows it with greater flexibility and higher strength before cracking.

As a function of that compression, the laminate necessarily looses volume (the volume of the expressed resin, air bubbles, and more compact packing of the glass fiber all summed) and is therefore thinner. If you think about it, this is necessarily the case: What is going to occupy the volume of the removed resin, bubbles, and loosely packed fiber when you bag? Answer: nothing. It's thinner than unbagged laminate.

Finally, stiffness is a function of the cross-sectional thickness of a material. Thinner = less stiff in flexure, for all materials, always. You are correct that it is more fragile as well: It's less likely to flex, but when it does, its more likely to break.

This is why I said it's not better, its just stiffer.

By adding additional layers of GRP, they get the stiffness they need and the strength they require without bagging. The hull is heavier than it could have been, but the cost is much lower and it is cost that they are optimizing for.

Beneteau actually refers to these hulls as "polyester" and "plastic" rather than "fiberglass" in their marketing materials in Europe.
__________________
mstrebe is offline   Reply With Quote
Old 16-12-2014, 21:11   #276
Registered User
 
Fluer de Mer's Avatar

Join Date: Sep 2014
Location: San Francisco
Boat: O38 & J24
Posts: 164
Images: 2
Re: Beneteau 38

Update:
Wow.
Beneteau is now involved and the response has been great.
Also the dealer is bending over backwards to make this a positive experience.
I will explain more once the boat is delivered.
In the meantime, thank all of you for your input and advice.
__________________
Fluer de Mer is offline   Reply With Quote
Old 16-12-2014, 21:13   #277
Registered User

Join Date: Jun 2014
Location: San Diego, CA
Boat: Beneteau Oceanis 38
Posts: 563
Re: Beneteau 38

Quote:
Originally Posted by Fluer de Mer View Post
Update:
Wow.
Beneteau is now involved and the response has been great.
Also the dealer is bending over backwards to make this a positive experience.
I will explain more once the boat is delivered.
In the meantime, thank all of you for your input and advice.
Fantastic! That's the best possible response at this point. Keep us posted.
__________________
mstrebe is offline   Reply With Quote
Old 16-12-2014, 23:14   #278
Registered User
 
Finnsail's Avatar

Join Date: Jul 2013
Location: San Diego, CA
Boat: Oceanis 35
Posts: 38
Re: Beneteau 38

Quote:
Originally Posted by mstrebe View Post
But then the dealer got their model and I had a look and I'm glad I didn't wait. It's a fine boat, but it's only 32' long (not sure why they call it a 35), forward berth is much too small for me, there's also no space at the foot of the berth to the removable bulkhead, and most importantly, the boat is nearly the same price as the 38'.
Which dealer received an Oceanis 35? I guess the first ones are getting delivered now.
__________________
Finnsail is offline   Reply With Quote
Old 16-12-2014, 23:23   #279
Registered User

Join Date: Jun 2014
Location: San Diego, CA
Boat: Beneteau Oceanis 38
Posts: 563
Re: Beneteau 38

Southcoast in San Diego & Newport.


Sent from my iPad using Cruisers Sailing Forum
__________________
mstrebe is offline   Reply With Quote
Old 17-12-2014, 05:07   #280
Registered User
 
Polux's Avatar

Join Date: Nov 2011
Location: Portugal/Med
Boat: Comet 41s
Posts: 5,757
Re: Beneteau 38

Quote:
Originally Posted by Fluer de Mer View Post
Update:
Wow.
Beneteau is now involved and the response has been great.
Also the dealer is bending over backwards to make this a positive experience.
I will explain more once the boat is delivered.
In the meantime, thank all of you for your input and advice.
Really happy for you When you can tell us the all story, including that defect.
Polux is offline   Reply With Quote
Old 17-12-2014, 07:58   #281
Registered User
 
RKsailsolo's Avatar

Join Date: Mar 2013
Location: St Paul, US
Boat: Jeanneau 349 2015
Posts: 706
Beneteau 38

Quote:
Originally Posted by Finnsail View Post
Which dealer received an Oceanis 35? I guess the first ones are getting delivered now.

When I engaged FL Beneteau dealers at Annapolis they did not have the 35 but both offered discounts if I would order. I imagine they've each got one now.
__________________
RKsailsolo is offline   Reply With Quote
Old 17-12-2014, 08:01   #282
Registered User
 
RKsailsolo's Avatar

Join Date: Mar 2013
Location: St Paul, US
Boat: Jeanneau 349 2015
Posts: 706
Re: Beneteau 38

Quote:
Originally Posted by Fluer de Mer View Post
Update:
Wow.
Beneteau is now involved and the response has been great.
Also the dealer is bending over backwards to make this a positive experience.
I will explain more once the boat is delivered.
In the meantime, thank all of you for your input and advice.

That's good news for prospective buyers. Now we can get a first hand experience through your eyes of the depth of the commitment that Beneteau has made to their service capability.
__________________
RKsailsolo is offline   Reply With Quote
Old 17-12-2014, 23:03   #283
Registered User
 
Finnsail's Avatar

Join Date: Jul 2013
Location: San Diego, CA
Boat: Oceanis 35
Posts: 38
Re: Beneteau 38

Quote:
Originally Posted by RKsailsolo View Post
When I engaged FL Beneteau dealers at Annapolis they did not have the 35 but both offered discounts if I would order. I imagine they've each got one now.
I checked with our local dealer today (South Coast Yachts) and their first Oceanis 35 has not yet arrived, but should be arriving in time for the San Diego Boat Show in January. The second one to arrive will be ours. We don't have an estimated delivery date yet. We ordered one after Annapolis.
__________________
Finnsail is offline   Reply With Quote
Old 18-12-2014, 05:18   #284
Registered User
 
RKsailsolo's Avatar

Join Date: Mar 2013
Location: St Paul, US
Boat: Jeanneau 349 2015
Posts: 706
Re: Beneteau 38

Quote:
Originally Posted by Finnsail View Post
I checked with our local dealer today (South Coast Yachts) and their first Oceanis 35 has not yet arrived, but should be arriving in time for the San Diego Boat Show in January. The second one to arrive will be ours. We don't have an estimated delivery date yet. We ordered one after Annapolis.

Congratulations! Awesome choice Finnsail. I am not quite there yet myself.

After my fifteen month investigation of the next boat, my wife and I sat on the foredeck of the Oceanis 35 at the Annapolis show and said "This is it. This is our boat." We sat there for five minutes discussing how much we liked it over the Jeanneau 349 and other mono hulls at the show, but ten minutes later we moved to the Oceanis 38 and left the show thinking the 38 is the better value due to more boat size for less than $50k additional cost.

Today, I am favoring the 35 once again but need to thoroughly study how my six foot frame fits in the forward and rear quarter berths.

Why did you go with the 35 vs. the 38?
__________________
RKsailsolo is offline   Reply With Quote
Old 18-12-2014, 09:26   #285
Registered User
 
Finnsail's Avatar

Join Date: Jul 2013
Location: San Diego, CA
Boat: Oceanis 35
Posts: 38
Re: Beneteau 38

Quote:
Originally Posted by RKsailsolo View Post
Why did you go with the 35 vs. the 38?
Thanks RK!!

We were in a process of buying a much larger boat but run into to some unforeseen complications in my plan to make it happen this year. Instead of delaying the purchase by 2 years, we decided to go with the "smallest big boat" that we really liked. We had the Bavaria Cruiser 33, Jeanneau 349, Catalina 315, the new Hunter 31, and the Oceanis 35 on our list to checkout when we went to Annapolis. The list was quickly reduced to the J-349 and OC-35.

Regarding the 35 vs 38: I'm married but we don't have kids. We don't anticipate many overnight guests. We don't need a large forward berth since the aft cabin is huge in the 35. I'm 6 feet tall and the aft cabin feels massively large (the aft cabin in the J-349 felt tiny and was one of the main reasons we didn't choose it). In my opinion, if you need a large forward berth, the 38 is the way to go. Otherwise, the 35 gives you practically the same boat with lower slip fees etc. For the two of us, we saw no reason to go with the 38.

Good luck with your selection process!
__________________

__________________
Finnsail is offline   Reply With Quote
Reply

Tags
beneteau

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 09:59.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.