Foam Core Hull

[baycruiser]

I have had 3 different airex foam boats over last 30 years all have been and still are VERY sound airex is definately a closed cell foam all foams are NOT the same currently my cat is epoxy over airex and I know that it is bulletproof lite and very easy to repair .Read lock crowthers engineers testing of airex over 30years ago still true and as for so called boat surveyors the less I know them the better there are exceptions but not the rule be very careful who you listen too .Rely on good sound practical boatbuilders(also hard to find) and owners who do or supervise their own work and dont be afraid to sack incompetence so stay close to any repairs and in control ..osmosis,wood rot are definately in almost all cases repairable on any good design and well made boat .There are different resins and different foams be aware of their differences and use them accordingly But as a type of constuiction material airex foam laminate is far superior on any multi /boat for strength durability repairability or any thing else

[OrangeCrush]

Originally Posted by robert sailor

I doubt it was a mistake on the hull thickness...

You're probably right but I was just repeating what I'd read. I found the source, Cruising World called it a "miscalculation": http://www.cruisingworld.com/sailboa...e-stern-beauty

Then again they are talking about the SC 35, but I think they're both great boats.


Sent from my iPhone using Cruisers Sailing Forum

[StuM]

Originally Posted by Van Der Beek

Sailboats are all monohull double u. Anything else is either a catamaran or a trimaran, also known as glorified rafts / party barges with sails.

Sailboats have a grace, a charm, a history and elegance about them that catamarans and trimarans all lack.

Sometimes, it's so hard to tell.

[StuM]

smj's post:

Do some research, you will find the catamaran came way before the monohull.

Van Der Beek's alleged quote:

Originally Posted by smj
Do some research, you will find the catamaran came way before the sailboat.

Originally Posted by Van Der Beek

I'm not a moderator so I cannot edit your posts.

Changing the wording in a quote without acknowledging that you have done so is rude, ignorant, deceptive, offensive and indicative of character.

[Polux]

Originally Posted by smj

Thanks for that wonderful insightful post. Do some research, you will find the catamaran came way before the monohull. Just a little history!
..

Why do you say that? The first boats were monohulls namely dugout canoes and they date from prehistoric times (45 000 years ago). Even if you are only talking about sailboats it seems logic that have been the first boats monohulls they would be the first to use sail.

The first references to trade routes that imply the use of sailboats come from India (6000 years ago) but the Island of Crete was colonized 12 000 years ago and they probably used some form of basic sail. Minoic civilization that was based in sea trading flourished 5500 years ago and made extensive use of sailboats.

I believe that proas and catamarans were only used by the culture that colonized the pacific Islands and that started "only" 4000 years ago.

Anyway this is only relevant for the history of boats and sail.

[smj]

My mistake, ballasted monohulls.

[Celestialsailor]

Originally Posted by rourkeh

There is no way I would own a hull that is manufactured with core below the waterline. It is a disaster waiting to happen, and because you cannot see it does not mean water ingress has not occurred.
This is an excellent summary of why not to use coring below the waterline.
Cored Hull Bottoms
it is the end to any argument in favor of this idea.

I was just going to post that site when I saw your post. I had been looking for a Corbin before my Hallberg-Rassy. It was my understanding (but I could be wrong) that Corbin builder did built a few hull solid. The owner of the boat I was looking at in Emeryville, Ca. was furious that I didn't want the boat because it was cored.
Rogers and Associates Marine Surveyors even suggested that I stay away from cored hulls as they had seen delam situations.
My hallberg-Rassy is solid f/g hull and deck with divinycell cabin top. Yes coring a hull does make a stiffer boat. But it's not the only way to achieve stiffness...it's just the cheapest way. My Hallberg has two longitudinal stringers running the full length of the hull. They are a glass channel measuring 2"X4"s and laid up 1/2" thick. Then the bulwarks are used as a stiffener also...See picture below>
They run the entire deck length, 4" to 6" high and 1 1/2"s thick. The boat does not flex with that set up and no one makes boats like this anymore.

[Celestialsailor]

Originally Posted by SailingFan

Normally I would stay out of this specific conversation, but as I read the thread today, and checked up on the articles linked, something becomes painfully obvious, yet nobody seems to have made the clear distinction between single layer hulls of today versus their grandparents of the 70's, that the older hulls of real thickness were heavier in weight, but did not oilcan and are very easy to repair, where the ones of today are nothing of that type, are excessively flexible, and require a tray insert to use in even relatively benign conditions on inland waters.

This was my thinking also when it was mentioned that core was equally exspensive or more so, compared to solid glass...of today. A 1'4" thick hull on a 40 footer oil cans easily. My hull is thick and well stringered. To do that these days it would put a boat company out of business.
In short a quality built. Hallbergs were originally built for the North Atlantic.
And to address another point, there is a Dufour 35 in the yard no which the keel bolts were leaking. Apparently the aft bolt is tucked away in some sort of inaccessible pocket. So they are merely filling it with an epoxy mix.

[robert sailor]

Originally Posted by Celestialsailor

I was just going to post that site when I saw your post. I had been looking for a Corbin before my Hallberg-Rassy. It was my understanding (but I could be wrong) that Corbin builder did built a few hull solid. The owner of the boat I was looking at in Emeryville, Ca. was furious that I didn't want the boat because it was cored.
Rogers and Associates Marine Surveyors even suggested that I stay away from cored hulls as they had seen delam situations.
My hallberg-Rassy is solid f/g hull and deck with divinycell cabin top. Yes coring a hull does make a stiffer boat. But it's not the only way to achieve stiffness...it's just the cheapest way. My Hallberg has two longitudinal stringers running the full length of the hull. They are a glass channel measuring 2"X4"s and laid up 1/2" thick. Then the bulwarks are used as a stiffener also...See picture below>
They run the entire deck length, 4" to 6" high and 1 1/2"s thick. The boat does not flex with that set up and no one makes boats like this anymore.

Longitudinal stringers running full length is not an uncommon way to strengthen and stiffen the hull, many builders dI'd it that way but these days on larger boats it's more common to core the hull. Either way is just fine, better in my opinion than thin hulls with glued in full liners.

[44'cruisingcat]

Originally Posted by Van Der Beek

Sailboats are all monohull double u. Anything else is either a catamaran or a trimaran, also known as glorified rafts / party barges with sails.

Sailboats have a grace, a charm, a history and elegance about them that catamarans and trimarans all lack.

Surprised anyone would use such poor quality bait these days.

Anyway, my experience has been that all monohulls are motorboats. Some have sails, apparently for decorative purposes.

They can be attractive, as dive sites especially with a few years coral growth on them.

[44'cruisingcat]

Originally Posted by Polux

Why do you say that? The first boats were monohulls namely dugout canoes and they date from prehistoric times (45 000 years ago).

Yes, the first were hollowed out logs which proved to be very unstable.

Two approaches were taken to improve stability. The low tech way was to half sink the canoe with rocks.

The more advanced method was to attach another hull or outrigger.

[Matt Johnson]

Originally Posted by a64pilot

Yes and unprotected spade rudders

How much protection and strength does that little bar really add to an Island Packet's rudder? Always thought it was just to deflect crab pots.... no way that's adding strength.

Matt

[StuM]

Originally Posted by Celestialsailor

This was my thinking also when it was mentioned that core was equally exspensive or more so, compared to solid glass...of today. A 1'4" thick hull on a 40 footer oil cans easily.

A 1 foot 4 inch thick hull?

[Van Der Beek]

Originally Posted by StuM

Changing the wording in a quote without acknowledging that you have done so is rude, ignorant, deceptive, offensive and indicative of character.

If you refer to sailboats they are all monohulls, and catamarans and trimarans are all multihulls. Monohulls are refered to as sailboats, because that's what they are. Multihulls are refereed to as either catamarans and trimarans, because that's what they are.

If you find it rude, ignorant, deceptive and offensive to change the term in order to make a point with a twinkle in your eye that's up to you, StuM. Point was I was in no position to change his posts and point is changing the term was done in an open way for everyone to see. Assuming you take the time to actually read the posts people make. Take a chill pill.

Post 111 I actually missed last night, had I seen it I would have catched up to what he meant. I was still in the frame of mind of him saying I had changed his post which confused me. It was late last night I was tired, not using it as an excuse just saying.

Originally Posted by 44'cruisingcat

Surprised anyone would use such poor quality bait these days.

I'm surprised anyone would bite which such poor quality bait, sometimes that's all that's needed

[downunder]

Originally Posted by Van Der Beek

If you refer to sailboats they are all monohulls, and catamarans and trimarans are all multihulls. Monohulls are refered to as sailboats, because that's what they are. Multihulls are refereed to as either catamarans and trimarans, because that's what they are.

If you find it rude, ignorant, deceptive and offensive to change the term in order to make a point with a twinkle in your eye that's up to you, StuM. Point was I was in no position to change his posts and point is changing the term was done in an open way for everyone to see. Assuming you take the time to actually read the posts people make. Take a chill pill.

Post 111 I actually missed last night, had I seen it I would have catched up to what he meant. I was still in the frame of mind of him saying I had changed his post which confused me. It was late last night I was tired, not using it as an excuse just saying.




I'm surprised anyone would bite which such poor quality bait, sometimes that's all that's needed

Rather i believe all vessels with sails are sailboats be that monohull, catamaran, trimaran or proa.

Catamarans or trimarans without sails are power or motor catamarans and trimarans.