ferro-cement

[D'ARTOIS]

I have this book, additional some Australian and New Zealand GAP's.

Lately I have seen some Ferro yacts and they look good if they are professionally built. Still, living in the Philippines, where there is plenty of very useful hardwood available at low cost, I would stay with the making of a wooden vessel.
It's not the labour that couns, it is the professional labour that makes the boat. The ferro yacht's making, the application of the mix of cement (with it's additions) is a continuous process - irreversible and requiring specific knowledge.

PAR hits the nail on the head with his summary of the Ferro yacht's history - that the pro-made boats might last long whilst the hippie style of working has probably disreputed the material.

I have only one experience in a yach that was built by a pro company and that was build like a brick ####house and moved that way also, and that is too slow for part of my Irish blood.

(BTW Mike, if you follow this post, did you own a Hartley Fiijan 50 ' junk rigged two-master?)

[JonathanCole]

Originally Posted by tdw

Was wondering if anyone knows about using ferro-cement over insulfoam (expananded polystyrene) as a frame?

I notice that this original inquiry got kind of glossed over as various experinces with ferro-cement were related.

I think from the various input so far on this thread, though, we can see that it is possible to build a good, long lasting hull with ferro-cement as long as it is done correctly.

How about catamaran-style pontoon hulls? If a solid foam core is made, like they do with surfboards, then you coat the core with epoxy to seal it and lay the wire mesh over the epoxied core ( I would prefer corrosion resistant stainless mesh or vinyl-coated as zinc coated wire reacts with the alkaline cement causing the zinc coating to fail and eventually rust to begin in the wire) before applying the cement.

This way, the inside of the hull requires no finishing. The foam core can be hollowed out after curing leaving a few inches which can be glassed.

Is there something wrong with this approach? If it worked you get a "bullet proof" hull with low maintenance and long life.

[D'ARTOIS]

Jonathan, I don't think that the usefulness of ferro goes in that direction. Although, a good many houseboats in Holland do have concrete basements, for obvious reasons. Long during resistance against waste-flooded inland waters, polluted with all kinds of wastewater, chemicals etc.

I have looked up a book I have: The Ferrocement Yacht, In Introduction; by Baugh, Bowen & Kenyon, maybe published in the mid '80s.

Loolking through it after some 15 years, I reconsider my opinion.
Graeme Kenyon, one of the authors, states that the emphasis of ferrobuilding is primarily to understand the material, rather than being an expert yachtbuilder.
The more I look into the subject the more convinced I am that this is another way of yachtbuilding, specifically useful for displacement and heavy displacement yachts. Many fine yachts were built this way:among among a stunning replica of L. Francis Herreshof's Tioga, named Okere, built by Jack Hargreaves in Auckland.

This book I have was published by "The Journal of Ferrocement" POBox 15-447 - Auckland 7, New Zealand.

There is a wealth of information to be found in this booklet and helps to underatnd the material considerably. Before you start such a project, get as much information as possible. There are a few loopholes in this process and
again, understanding of the material is of vital importance.
All of the comments of Paul (PAR) are to be considered seriously before one start such a project. Specifically in a country where so many alternative materials are available.

[JonathanCole]

Originally Posted by D'ARTOIS

Jonathan, I don't think that the usefulness of ferro goes in that direction.

Is your opinion on this based on the weight of the ferrocement compared to the displacement of each cat hull? I know light hulls are best, but also good is a tough, low-maintenance structure.

Although, a good many houseboats in Holland do have concrete basements, for obvious reasons. Long during resistance against waste-flooded inland waters, polluted with all kinds of wastewater, chemicals etc.

If your houseboat is actually designed to cruise, then you also have the issue of floating debris and dangerous sharp objects below the water surface (sunken boats, cars, and any kind of junk that might end up in the water).

All of the comments of Paul (PAR) are to be considered seriously before one start such a project. Specifically in a country where so many alternative materials are available.

Well, that is exactly to the point. When so many materials are available which ones make the most sense for a durable, low maintenance, cost-effective hull. Also nice if it would be a recycleable material which may become a big issue in the not too distant future. So far my bet is on HDPE, but the technique has not yet been developed to make hulls over 26 feet (< 8 meters). I am in discussions with a rotomolding expert about developing larger machines.

[MikeJohns]

I have some experience with ferro.

The durability of the material for the prudent careful seaman is 2nd to none.

The impact resistance is poor with brittle failure at yield. However the strength is suprising.
A 40 foot hull sold by the insurance that was washed up high and dry here was purchased by a gentleman who stripped all the worthwhile parts, part of the deal was that he was to dispose of the hull, large men with large heavy hammers made no impact on the hull at all it took a large excavator to break her up.

Designers using this material should be aware of the weight issue and design accordingly, there are many successful and beautiful ferro sailing boats in this part of the world, but a designer who understands the material is paramount in the choice of a design.

Survey I have done by chipping away the inside and or by industrial x-ray. The material usually shows any internal corrosion by spalling. Diesel soaks through the plater and destroys the zinc off the mesh leading to loose mesh and subsequent water capillaries.

I just surveyed a concrete 100 foot 100 tonne explosives storage barge that was badly fractured from ships coming hard alongside, this was poured concrete and reinforcing bar with pre-stressed cables fully grouted into the base, almost impossible to survey adequately without demolishing it.

Hartley in NZ have recently released a new book on the repair of ferro hulls, I do not possess it but it is said to be the definative reference for builders and repairers alike.

[FOsorio]

I intend to start work on my ferro cement boat. Can I somehow get a copy of a ferro cement boat construction manual.

[CGN]

For reference

http://www.fao.org/DOCREP/003/V9468E/V9468E00.HTM

[cyclops]

Are we in agreement? Ferro-cement hulls may crack in a collision, but they only leak. The bilge pumps are never stressed to keep the boat afloat till repairs can be done. Sounds like the right hull material to be mandated for all Offshore Racing Boats. Let the captains push the daylights out of them.

Ferros this, Ferro's that!

Answer me this!

Were the twin towers in NYC (You know the ones that two jets flew into on 9/11, which subsequently collapsed), or were they not - built of concrete over steel reinforcing?

If it's such a strong material, etc etc etc - how come - it collapses under it's own weight like it did on 9/11?

I can't help beleiving the designers of those two buildings, knew all about the strengths of cement over steel, they probably wrote university thesis on just such things, before they were qualified to design / build to build the two towers.

Now to the chase, - why did that small 6 story building next door to the twin towers, which wasn't hit by any planes - and didn't have any part of the two towers collapse on it (remember - they went down almost as if an expert in demolition had imploded them perfectly), why did it collapse a few hours after the other two went down?

Why didn't the pentagon self implode and collapse?

You can all sail anywhere you like in steel and concrete - but not this little black duck!

Cheers!

[gonzo]

They were office buildings, not bunkers. The heat of the burning fuel fractured the metal beams. It was a "glass and steel" building, not ferrocement.

[PAR]

You should speak what you know, Trouty.

The Twin towers of the WTC were a revolutionary design in the early 1970's when it was conceived and a rather brilliantly executed testament to the designer's engineering skills.

The buildings were built around a central steel frame core, which housed the mechanical chases, elevators, stairs, etc., and a lighter steel frame outer shell. This was clad with light weight alloy panels and glass of matching color. This construction permitted the building to be considerably lighter (read cheaper, just as strong and faster to build) and free of the columns typically seen in the grid style of construction in other tall buildings. The open floor plans allowed much freedom in the interior design elements.

Of course, much concrete was used in the foundation and first 100 feet of the structure (over half of this was underground) which saved on dimensional steel costs and speed of construction (not to mention, hold back the near by waters, surrounding the island). The floors were stressed concrete panels, specifically designed for the building and common in free span areas.

The buildings fell down because the floor support beams sagged as they reached near the melting point of steel, from the 100's of thousands of gallons of burning #2 aviation fuel. When they had sagged enough to pull their fasteners or other structural members out of column, they fell to the floor below. This generated a classic cascade failure, easily understood by watching the footage in slow motion. As each floor impacted the lower one, a slight hesitation can be seen in the first several floors below the beginning of the collapse. This was the lower floor bending and then giving way, under the much higher then ever expected loading.

Around a dozen buildings came down that day, Trouty. Many from the heat of a very intense fire, cooking their outer skeletons off. Others from the debris that fell a fifth of a mile to the ground, plunging through surrounding building like they weren't even there. Any object, if dropped from any height, at or above sea level, will fall at 32 feet per second until it reaches it's terminal velocity, which will vary with it's aerodynamics, (humans max out around 120 MPH in the spread eagle position). Dropping from say several hundred feet, an office chair will smash a car flat, a pad of Post-Its will kill a man, etc. Imagine what a 12" x 24" x 50' steel "I" beam would do, upon impact with anything.

As for the designer of the WTC, he was a Japanese man of particular note, well regarded in the industry, though a bit of a surprise when his name was selected. He wasn't a kid toying on graduate work. He's masterful effort in the many elements of the WTC structure showed a wise, cautious, inventive and highly skilled individual.

This same idea of speaking what you know applies to ferro cement construction techniques also. Because you don't understand the dynamics of the engineering involved doesn't mean it's no good. It just means you don't understand.

Par, - with no malice intended, i could easily shoot your melted steel theories to hell n back - with just one good paste from any of the conspiracy websites about 9/11.

Fpr example - Jet fuel doesnt burn anywhere NEAR the melting point of steel and so on...(roughly half on a good day!),, BUT - with mooderation what it is here - your political comments would be acceptable while mine wouldn't.

This simply means theres no point me countering your post - I would be in effect wasting yours mine - the readers and mooderators time.

Frankly - my times worth more to me.

Cheers!

[gonzo]

Par correctly says that it reached near the melting point. The metal deformed and cause the failure.

[Wynand N]

Originally Posted by trouty

Ferros this, Ferro's that!

Answer me this!

Were the twin towers in NYC (You know the ones that two jets flew into on 9/11, which subsequently collapsed), or were they not - built of concrete over steel reinforcing?

If it's such a strong material, etc etc etc - how come - it collapses under it's own weight like it did on 9/11?Cheers!

trouty, what do you smoke
A Building is a building and a boat a boat, both have totally different design and engineering diciplines - I cannot see what you are getting at.
That said, no damn Boeing is going to crash deliberately into one's boat...

Par and Gonzo did reply in good faith and looking at the standard of PAR's reply to the tone of yours, no contest. Rather go spend your worthy time constructively at conspiracy web sites.

trouty, what do you smoke

I only smoke in bed and then only on a good night!

Although...this area is renowned for it's hooch...no doubting that!

Anyone know where a mountain man like me can rustle up some good ol hillbilly info on makin his own moonshine still?

Funny thing that - we aren't allowed to make grain alcohol - coz - being a part of the commonwealth, when we were settled - the Queen wanted to protect Bergalia's beloved distilleries in Scotland, and so - distilling of grain alcohol, in Aus was prohibitied (Prohibition...I can see Luke 'n Daisy Duke just gassin up the General E Lee, right now!).

BUT - funny thing - I "discovered" (having a good nose for a wee dram) that a crowd in Tasmania called "Sullivans Cove" make an Australian Whiskey!!!!!

How the heck - do they get around prohibition?

Now - if I'm not wrong, we have ourselves an Australian constitution, somewhere in which it states - that No State of the Commonwealth - can enact a state law, that puts a member of an industry in that state at a competitive disadvantage to a competitor in another state in the same commonwealth.

Ergo - if Tasmania's a state of Australia, and THEY are allowed to brew whiskey - then the Australian constitution guarantees me that very same right!

So - moonshine here I come - just point me in the right direction fellers - some one heres gotta know how one goes about setting up a moonshine still?

Can't be that hard can it?

Anyone sees a big mushroom cloud, waaaay down south - it's Just ol trouty tooling around in his bark hut down by the river, pay it no attention!

Blue Moon Brew!

Ahhhhh - course I'll be needing Bergalia's assistance for a while, strictly for for quality control purposes you understand!!!!

Cheers!