Ferro Cement hulls

[JanusMatzen]

Dear Shipmates,

I am looking to build a motoryacht for living on with a family of 4.

One idea is to have a shipbuilder build a hull in Ferrro Cement as it should be very low maintenance if done correctly.

But where do I find a shipbuilder that has the know-how?

The size should be around 20 meters long and 6 meters wide.

Anyone with info - please help.

JANUS

[Raggi_Thor]

Search this forum :-)
For example http://www.boatdesign.net/forums/sea...earchid=862795
and
ferrocement

I don't think ferrocement is as good as wood, grp or steel.

[darr]

An alternative product would be Fer-A-Lite. Same concept as Ferro-cement, however it is a polyester based mortar mix. More information can be found at www.fer-a-lite.com.

As a testament to the strength and durability of Fer-A-Lite, the schooner Anne, a fer-a-lite hulled 70' Schooner is currently engaged in a 1000 day non stop voyage. Approximately two weeks into the cruise she was hit by a freighter and only suffered damage to the steel bowsprit. You can find out more information at www.1000days.net

there has been so much said and done abt ferro in the site
Look, ferro has the strength of an egg, exactly that, its ok as long as you hit nothing,
I have seen people afraid to move down here in the Pacific, with coral around
You ferro resale is ZILCH
but if youa re set on it, and you have enough liferafts)
google up SAYER, from NZ , he built the best in the world, and if you could find a second hand one, you would get a cheap boat
As Raggi says, go steel if you want an amatuer built boat

[jehardiman]

The boatbuilder you are looking for is the

Fibersteel Corporation
West Sacramento, CA, USA

I was aquainted with the owner, but I don't think they are in business anymore. They had molds to do exactly what you are asking for.

The owners website http://home.att.net/~miorns/

I have been trying to disuade you by digging stuff out
uncovered many things

Posts: 2001

Re: Ferro cement [Re: alant]
#447392 - 30/12/2003 22:19
Edit post Edit Reply to this post Reply Reply to this post Quote Quick Reply Quick Reply

Never, and would never own one, but recently managed a company as part of a corporate recovery that among other things employed around 35 surveyors of ships. As part of managing risk it was unanimously decided that ferro-cement boats would no longer be surveyed because of the risks in and difficulty of assessing their condition. Fortunately there are very few ferro small commercial vessels (for good reason I suspect) so we did not have to tell many clients that we did not want them any more.

However, almost all ferro cement pleasure boat owners that I have come across claim that they are the best thing around and essentially have no faults. A worrying claim for any boat, perhaps? But they are cheap (second hand that is, they are just as expensive new as other constructions if fitted out to the same standard) and if that is an important consideration, why not?

John

[Bergalia]

Little to add to the above advice except question their 'fragility'. I spent a summer helping fit-out a couple of ferro-cement shells (cement mixed with chopped fibreglass over chicken mesh wire) built by an Inverness firm Concrete Afloat (since sunk).
The wire frames once erected were 'sheathed' by a couple of local plasterers and as they cured shaved into shape by a local stone mason...
Fitting out was done on pre-inserted wooden frames - 'nailed' and glued in place. However the finished articles did float - although I never heard of them going to 'sea' but used mainly for sailing in the Great Glen - Loch Ness and the Beauly Firth (sheltered). One did have a collision with the Navy pier at Cromarty, and demolished it - the pier that is - without apparent harm to the vessel. (The pier had been built by the Admiralty in the 1930's. It was elderly timber and it's only claim to modest fame was as a bit player in a mutiny by a handful of Naval Ratings).
They were cold vessels to work in, and according to their owners cold and wet in performance. But other than that....

[joergen]

If you have to go for ferro, dont make one, purchase a secondhand, its cheaper. there should be some in scandinavia, i know one sailing vessel in stockholm thats been for sale a couple of years.

[MarkC]

I guess I could post this list here as well.

A good text to read:

FERROCEMENT AND LAMINATED CEMENTITIOUS COMPOSITES

by Antoine E. Naaman, Ph.D.
Fellow ACI; Fellow ASCE; Fellow PCI; Fellow IFS
Professor of Civil Engineering, University of Michigan, Ann Arbor
Hardcover; 372 pages; 160 figures and illustrations; 43 pages containing 120 photographs; design aids; bibliographic references; 7.25x9.5 in.
ISBN: 0-9674939-0-0; LCCN: 99-96382
Copyright 2000

See also the University of Michigan and their concrete canoes:
http://www.engin.umich.edu/team/canoe/construction.html

Another reference text from the Food and Agriculture Organization of the United Nations:
http://www.fao.org/docrep/003/V9468E/v9468e00.HTM
Fishing Boat Construction: 3. Building a Ferrocement Fishing Boat

Here, in Boatdesign.net design articles - there is the US Navy Ferro Cement Boat Building Manual in PDF.

There is also the:
American Bureau of Shipping:
(Document ref. Sections 5.7 and 10)

[Raggi_Thor]

I don't understand the fascination for cement!
I have worked a little with it at home, it's messy and "unprecise", it's heavy or weak.
Is it so much cehaper than steel, aluminium, wood?
Even if it was free, in boat with 15 tons displacement, you use maybe 4 tons of wood. How much will that cost you compared to the total?

[Raggi_Thor]

OK, I read the first part of the FAO paper,
IF you cant find or afford other materials, THEN consider cement :-)

FAO:

In recent years the destruction of forests has now excluded various species of good quality boatbuilding timber from general use, reducing availability and spiralling costs upwards. For wooden fishing boats, the added burden of sheathing protection against marine borers particularly in warmer waters, and ice damage in cold waters, also need to be taken into account in their final costs.

Plywood offers the chance to achieve strength with lightness and is easily maintained and repaired. However, its flat sheets impose design limitations in small craft and marine grades are not widely available.

GRP (glass reinforced plastic) or FRP (fibre reinforced plastic) construction, whilst having a wide market in developed countries particularly for leisure craft, has been held back in some underdeveloped countries for various reasons including high setting up costs, requiring factory air conditioning, dust, humidity, and quality control. The shelf life of materials, availability of materials for carrying out repairs, and high taxes on imported materials, present their own local difficulties Whilst fibreglass boat hulls can be mass produced and the mould costs amortized over a number of craft, for limited numbers and changes in design, it is much less advantageous compared with other boatbuilding materials.

Despite good weight and strength qualities, aluminium alloy requires greater technical knowledge in its construction to prevent exposure to dissimilar metals and great care whilst welding or bending, as well as taking account of alloy fatigue so as not to affect the materials strength. Availability of the correct alloy in many countries will also be a problem. Fishing boats made from aluminium have tended to be built in industrialised countries with the technical back-up to hand.

Steel presents the builder with an easier material to work with: there is plenty of information to consult; the materials are usually readily available worldwide; setting up costs can be fairly nominal; and good construction provides robust boats. However, in all phases of construction, steel needs to be nurtured against corrosion attack from initial storage to final painting stage, particularly in underdeveloped countries where maintenance, if carried out at all, is very often poorly done, resulting in a reduced life span. Good maintenance results in a longer life and a considerable increase in maintenance costs to keep the material in reasonable condition. Furthermore, high initial capital outlay and relatively high technology are required for plant, machines and tools. In the design, the shape of the craft will to an extent be governed by the equipment available to bend and shape the steel to acceptable limits, and the acceptance that generally speaking steel fishing boats would be constructed from 14 m L.O.A. upwards.

Ferrocement is a flexible and durable form of construction. It is easy to repair and possesses many features that help produce a well founded fishing boat. It is particularly suitable for moderate to heavy displacement designs with well rounded sections. However, good supervision in all aspects of construction is desirable, whilst in general the labour can be semi-skilled. Because ferrocement materials are analogous to the building construction industry, material availability worldwide is generally very good and cheap. Despite some poor construction in various places over the past twenty five years, which has hindered the acceptance of the material somewhat, there are enough fishing boats constructed in ferrocement around the world to give substantial claim for ferrocement to be positively accepted in fishing boat building.

[Bergalia]

Let's not forget that the 'Mulberry Harbour' sections were made of cement and floated out from Britian during WWII - and despite being bombed and shelled, for many years after were still 'floating' around the beaches of Dunkirk....

[Raggi_Thor]

Yes, and the larges production rigs, "plattforms" we call them, in the North Sea are built of concrete (and a lot of steel reinforcement), BUT do you want it for your boat? I don't :-) Add more lightness!

[Bergalia]

Originally Posted by Raggi_Thor

... BUT do you want it for your boat? I don't :-)

Of course not Raggi. You and I know that the only material the good lord meant us to use was timber... otherwise why would he give us trees...But you know human nature, experiment, experiment...

to compare a platform, bridge, whatever with a yacht is just plainly ridiculaous, come on you two snap out of it!!, like comparing a steel yacht hull with the Kursk hull. apples and pears, , who was talking about stairs, ah yes Koln Cathedral