21th Century Ferrocement Yacht Hull Technology

[Kayoko Monk 33]

My father has built two, a 46'6 Ketch and a barge, "Ferro-Cement, Design, Technique and Application" is an excellent reference book and was written by Bruce Bingham, the hull shown in this book to be the proper way to complete a hull was his Andromeda Design (Amphora) built by my father and sailed from SF to Newport RI with a run into South America. I sailed the boat from RI for 7 yrs after that, ended in Florida where she was sold. The barge is still in use as an office for Bowens Wharf, Newport RI. The cement is engineered with specific additives as to not react and gas with the 7 layers of wire mesh (galvi) and spring steel rod that tranverses the hull from port to stbd and Vice versa and crosses approx every two square inches and is tied with a very high strength high carbon bobby pins, twisted and cut with face cutting type pliers then struck flush, originally built on wooden frames which are removed once the armature is completed. Its suspended now by that 1/4 wire in a box frame. The engineered cement is sprayed from the inside and troweled smooth from outside, done by a company specializing in boats, then it is cured for 30 days with soaker hoses keeping the hull wet until it becomes cures and remains very flexible and plastic. The cement is coated below water lines with coal tar epoxy isolating and insulating the hull from sea water just like a steel vessel, bottom paint over that. The project is very labor intensive (7yrs) and when done properly is very sturdy as evidenced by the time we smashed into a full sized bouy, dead on the bow at 8 knots in SF bay resulting in a chip in the bow. I ran the boat aground on more than one occasion on the ICW, Fire Island NY, zero damage other than my pride. If you contact me direct my father is still living and very sound of mind, he is a wealth of information on Ferro Cement. Many bad hulls were done by inexperienced home builders in 60-70's giving Ferro-Cement a bad name.

[geoleo]

Originally Posted by HopCar

I wonder if using chopped glass fibers instead of steel wires might provide the same tensile strength that the steel provides but without the rust issue?

Au Contraie Sir! In late seventies glass fibers were tries as precast building wall panels. Some on very hi rise buildings. This proved a DISASTER! The fibers were also inevitabley at the outer surface of the panels. Over time (it started within 6-12 months)-- water started creeping up the FG fibers to the inside--- the winter came----POW-- the water expanded and spalled off the concrete. Every single building had to have all the FG panels replaced at a cost of hundreds of millions. :banghea d:

[leftbrainstuff]

Originally Posted by MtUmutSarac

Hello there,

This is my first post to the Forum and I want to present my best. My name is Umut , an archaeologist from Istanbul and want to build myself a ferrocement danish double ender yacht to myself.

I researched the concrete technologies for a very long time , even since DUCTAL from Lafarge invented.

Long story , short , the highest strenght concrete is reactive powder concrete.

That concrete consists lots of materials inside plus steel wires. These wires are few milimeters long. It uses only very fine powder materials

That concrete invented for bunkers , military facilities etc. Least 15 times stronger than ordinary concrete for hull construction. I dont know it makes 15 times thinner or lighter hulls also , get an technical advise.

I thought I can make a double flexible plywood sided shape changing mold for casting hull panels out of that concrete without using any traditional hand lay mesh,net or bar.

japanese and Italian Engineers invested lots of time and Canadian scientists to cast clean and basic out of textile flexible molds.

Than I want to epoxy or silicone fill each panel to other.

I want to get your opinions on that subject.

I found ISTON RPC or PRC is manufactured in Istanbul and next week I will get a technical analysis document plus price quote about that concrete

Cement based technologies have been completely displaced by much higher specific stiffness composites for structures that move.

An engineering trade study will not show concrete based technologies as being superior. As an engineer I can't see any benefits worth chasing. I see even less benefits in terms of marketing. Who would want to buy a concrete boat in this era?

Key parameters are specific stiffness, knowledge of the product by fabricators, fatigue resistance, ability to bond interfaces and load carrying elements, impact resistance, etc. Concrete technologies don't solve a problem for sailboat manufacturers.

Ferrocement was only a thing back in the 70s becauses boat builders couldnt source grp technologies. It was recognized as inferior back then.

There are some interesting membrane mold technologies for use with aerated concretes. They create structural arches and dome shapes. I can't see how they are a viable technology for building complex hull shapes.

You mention flexible molds. Stiff molds are needed to form complex hull shapes. Are you planning on bonding them together? I fail to understand the engineering rationale here.

Eventually we'll 3D print vessels. That is the disruptive technology i would be investing in.



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[Cadence]

Originally Posted by Jim Cate

Somehow, casually mentioning gluing panels together leaves me thinking that this methodology has not reached the state where a sound hull could be built. I can sorta believe that very strong panels could be built, but then convincing them to stay stuck together in heavy sea conditions... well, I wouldn't care to do a passage in such a hull!

There are so many well proven hull materials that putting ones fortune and ones life at risk with a totally unproven construction seems a bad choice to me.

YMMV, of course, and I suppose that the first folks to build in GRP suffered similar comments...

Jim

The whole idea seems like folly. Precast panels for buildings is great not for boats. JMHO I had done as much research in ferro before building in C-flex and glass. The plans seemed to be a big deal with an outfit in Alaska mainly for fishing vessels I think there was an outfit pushing it Down Under.

If someone was so disposed to build that way, I would suggest the conventional method.

[Bulawayo]

I have bought several hull, deck and bulheads and fitted them out myself and subsequantly sold them for tidy sums. 44' cruising cat looks an incredible product from what I have seen.
A thought occurred to me; why not encourage this new ferro boat building venture? - we might all learn something new and maybe, just maybe, it might work. If it doesnt, we have not lost anything - as long as the rescue services are not called out. After all, it was only a few hundred years ago that it was believed the world was flat.
I personally have strong doubts, but rather than voice this again, it having been already stated by those better qualified than myself, that we simply request regular progress reports and see what happens. My bet is on nothing ever happening. This project shall simply peter out.

Originally Posted by 44'cruisingcat

Seriously, why don't you just stick to talking about subjects you have some knowledge of?

People WHO HAVE BUILT BOATS are telling you about their real life experience of it. Why do you keep arguing from a knowledge base of ABSOLUTELY F***ING ZERO?

IMO you're a prime example of what's wrong with this forum. People who are unable to distinguish between what is merely their opinion and what is fact.

[Bulawayo]

Totally agree......

Originally Posted by 44'cruisingcat

Nope, I'm not being way too modest.


- Cruisers & Sailing Photo Gallery


It's really not that hard, technically. IMO any reasonably competent person could do it. If you call a plumber to change a tap washer, then no, probably not.

The most difficult part of building your own boat is simply staying motivated, and sticking to it to the end. People don't get the reality of a multi-thousand hour commitment. But the work itself isn't particularly mentally taxing at all. Just the opposite, in fact. It's the monotony and boredom that can be the biggest problems.

[atoll]

Originally Posted by Bulawayo

I have bought several hull, deck and bulheads and fitted them out myself and subsequantly sold them for tidy sums. 44' cruising cat looks an incredible product from what I have seen.
A thought occurred to me; why not encourage this new ferro boat building venture? - we might all learn something new and maybe, just maybe, it might work. If it doesnt, we have not lost anything - as long as the rescue services are not called out. After all, it was only a few hundred years ago that it was believed the world was flat.
I personally have strong doubts, but rather than voice this again, it having been already stated by those better qualified than myself, that we simply request regular progress reports and see what happens. My bet is on nothing ever happening. This project shall simply peter out.

potentially this could be a very interesting concept for building cheap bullet proof production hulls,probably better suited to larger fishing or commercial cargo type vessels,couple this with using a female mould, a non ferrous armature and infusion technology with the poly propylene reinforced cement,and it could be a winner

even cheaper than steel,and more durable,with no need to paint,apart from antifouling

[Djarraluda]

Originally Posted by leftbrainstuff

Cement based technologies have been completely displaced by much higher specific stiffness composites for structures that move.

An engineering trade study will not show concrete based technologies as being superior. As an engineer I can't see any benefits worth chasing. I see even less benefits in terms of marketing. Who would want to buy a concrete boat in this era?

Key parameters are specific stiffness, knowledge of the product by fabricators, fatigue resistance, ability to bond interfaces and load carrying elements, impact resistance, etc. Concrete technologies don't solve a problem for sailboat manufacturers.

Ferrocement was only a thing back in the 70s becauses boat builders couldnt source grp technologies. It was recognized as inferior back then.

There are some interesting membrane mold technologies for use with aerated concretes. They create structural arches and dome shapes. I can't see how they are a viable technology for building complex hull shapes.

You mention flexible molds. Stiff molds are needed to form complex hull shapes. Are you planning on bonding them together? I fail to understand the engineering rationale here.

Eventually we'll 3D print vessels. That is the disruptive technology i would be investing in.



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We used to have people sprucing Alloy boats as best - on the basis that this is what they built the 12m boats with, so.....
They seem to have forgotten the 12m class rule of no extra thickening of the hull. The Kiwis then showed us all how to engineer composites - despite the Americans wanting to drill holes to prove it, they dominated the actual real races on the water.
Now we have understanding of technology and perhaps, more of a capability to analyse the forces, so we can build in the appropriate materials for the size and style of vessel we want. That may be ferro, steel, alloy, cedar, or whatever composite we can develop. Isn't technology great, we get options.
Go with the research, good luck accessing the materials and achieving your dreams - but trust the engineers and naval architects to play their part in making it safe and durable for you.
AND - let us all know how it goes, you have obviously attracted the interest!

[barnakiel]

Yes, you have attracted some interest, and some comments from people who are never happy to see others try something new. Please disregard such people in the name of sanity.

A Chinese proverb goes that those who can't should not interfere with work of those who are doing.

Go ahead with your project see what happens. If it does not work while you believe it should, improve and try again.

Failure is a lesson and success this one is very sweet. Trust me on this, I have.

;-)

Do let us know how it is going. Do not think anything is wrong with this forum, any forum. It is just another social media place with all its pros and cons, like any other material. It is 'agora'. Every one has their say. Nothing wrong with that. We cannot have free speech without some involved inconveniences. Use the material (social and chemical) according to its properties and you end up finding ways and building things where others fail.

You are the man.

Cheers,
barnakiel

[Jim Cate]

Originally Posted by barnakiel

Yes, you have attracted some interest, and some comments from people who are never happy to see others try something new. Please disregard such people in the name of sanity.

A Chinese proverb goes that those who can't should not interfere with work of those who are doing.

Go ahead with your project see what happens. If it does not work while you believe it should, improve and try again.

Failure is a lesson and success this one is very sweet. Trust me on this, I have.

;-)

Do let us know how it is going. Do not think anything is wrong with this forum, any forum. It is just another social media place with all its pros and cons, like any other material. It is 'agora'. Every one has their say. Nothing wrong with that. We cannot have free speech without some involved inconveniences. Use the material (social and chemical) according to its properties and you end up finding ways and building things where others fail.

You are the man.

Cheers,
barnakiel

Hey Barney, how did you feel about the Flyin' Hawaiian? Did you encourage that fellow to disregard well reasoned cautions about his unusual methodology?

Just wondering...

Jim

[barnakiel]

Originally Posted by Jim Cate

Hey Barney, how did you feel about the Flyin' Hawaiian? Did you encourage that fellow to disregard well reasoned cautions about his unusual methodology?

Just wondering...

Jim

Jim,

I can't remember. I googled up Flying Hawaiian and an ugly boxish catamaran came up. Likely a fine liveaboard though!

If I did discourage that builder, I was wrong. I can't remember discouraging him though and it would be pretty rare of me to do so. I am much more in the 'try and see what results' club. No intention in this, this is just how I am mentally wired: an encourager far more than a discourager.

You may hear me at times sounding somewhat more cautious when it comes to actual sailing. But I think risks from building a poor boat are far fewer than risks from sailing one, esp. offshore. Building boats should not me mistaken for sailing oceans.

Others may be wired in other ways and feel more inclined to discourage things unusual, new, or apparently odd. I have such people in may natural family too, but not in the extended one.

Had Columbus asked everybody for advice, we would not have this conversation and this server would have been in China not in Phoenix, Arizona. As one person said: 'ask forgiveness, not permission'. This one, I think, applied judiciously, is the motto of anyone trying to achieve something new, something not achieved before.

So, to sum up, I think an inventor, a builder, an entrepreneur must at times explore the possibilities rather than listen to 'what they say'.

I have seen plenty of ugly ferrocement boats and if you look up an older thread on this forum you will likely find one of my less famous openers:

OP: Can we finally have a reasonable conversation on ferrocement boats.
B: Yes, provided you do not have one.

But I will be happy to see one day a well built and pretty ferrocement boat. OP intends to get rid of the mesh matrix and apply new (to me) molding methods. I think it makes sense to build a small proto and see what comes up. Just in case something does!

OK, so this is pretty much my answer even though if not 100% to your original question. It is OK with me if you bring up what I thought back then when that catamaran was being build. Maybe I was more pessimistic but I simply do not remember that boat too well. Put this on my age.

b.

[barnakiel]

I have just noticed I said 'him' where I should have said 'them'. I am not sure why I thought that an ugly boat could be build only by a male. Old, bearded one ... ;-)

b.

[tikirawker]

i hope you build it and take many photos along the way.
This sounds like a fun project to watch!
good luck

[darylat8750]

I hope you give it a go. I think it would make big sense to build a small boat first to keep the financial risk down. Keep us up to date on your progress.

Active experimentation with so idea of what you are trying to accomplish and the risks involved are way different than the Flying Hawaian. That project was a pipe dream by someone with an extremely small chance of success and a very poor idea what a development cycle is.

[rpaul]

Please excuse me, I do not know much about this technology BUT I do know about boat building.When considering this project, do start with the "end in mind" - if you are trying to prototype something and make a living / profession from it is one subject but if you are just thinking of building a boat for your own use and selling (potentially) later on, completely different subject.
And so on, and on.
Analyze VERY carefully what you want to achieve, forget technology and refrain CONSISTENTLY your desire to build so that you can be (if possible) realistic.
Desire to build is a dangerous call.
It all comes down to the "value" that this project will represent after a number of painful and costly years. Think of the overall monohull (crowded) market today and in a few years and so on. Consider the risks of project and specially associated to end result.
Assess yourself as a person able to commit to long term projects.
By the way, I completely agree to what was mentioned before as to hull construction being a small part of total cost and timing of boat building project. Having whatever hull fabrication technology will not provide substantial benefits for cost, labour and time . It can be a game changer for overall weight, esthetics (wood for ex.), future buyer perception, etc.