Ferro Cement boats

[catherine@brittany-gites.]

I have sailed many miles on ocean racing yachts mainly built from carbon, kevlar or cored grp. I am now looking to buy a cruising yacht and keep coming across ferro concrete yachts.

Can some one tell me a bit about this kind of material and I guess how good is it as a meterial and how difficult is it to care for compared to a GRP or Steel yacht

Many thanks

A search (top R/H corner of each forum page) of these forums (including archives) comes up with a couple of references to Ferro - this is one:

http://www.cruiserlog.com/forums/topic.asp...archTerms=ferro

Hope that helps for a start.

[Auzzee]

Hi Catherine, I used to be a ferro critic after listening to all the heresay stories of doom and disaster bandied about by the bar props at my local sailing club. A chance meeting with a ferro owner or two, and a little research led me to believe that ferro is an excellent boat building material.

Ferro gained a reputation for failure, just as ocean going trimarans did in the 60's. DIY builders who modified good designs, then built with poor quality materials of less substance than specified by good designers, meant there were some high profile failures which were seized upon by bar-room captains across the world. Both trimarans and ferro boats continue to suffer as a result.

Ferro had its hey-day in the 60's and 70's and a great proportion of the well built boats of the time are still afloat and represent great value. The reason why ferro is no longer a popular material is cost. The steel and concrete amalgam is as expensive as fibreglass and the labor costs in building the hull make ferro more expensive to build nowadays, than buying an equivalent sized fibreglass production hull.

As with any boat, you must buy with care as a bad fibreglass/steel/alloy/timber/carbon-kevlar...or ferro boat is still a bad boat. I would always choose to sail a good ferro boat before a bad boat of any other construction.

Many people will tell you that ferro has a poor resale value. This is totally untrue. You will most likely sell your ferro boat for at least what you paid for it. A look at prices over the past 10 years will show that the sailing world is beginning to realise the value of ferro. Prices are rising.

Ferro is strong and flexible, it is a good insulator, it is easily repaired, it is foot-for-foot the same weight and specific density as steel, for maintenance it requires only paint, and it does not suffer from degeneration through osmosis, rust or wood rot. Indeed is seems the only suffering is felt by the owner when confronted by others, who have heard from a friend of a friend's wife's boyfriend's mother's friend's husband who has never sailed offshore, but who vows that ferro is dangerous; in total disregard to the fact that the worlds biggest structures such as bridges and skyscrapers are made from ferro.

There are ferro boats in almost every anchorage where there are steel or plastic boats and it is my experience that genuine cruising people regard ferro well, as a result.

My advice is to consider buying a good ferro boat, if you want more boat for your money and a good resale in the future.

David

[steelfan]

I fitted out and sailed a 53 foot ferro about 20 years ago. The resale value is VERY low because of the scare stories. It is also a difficult material to fit out - cutting hatch points is a pig of a job. However, as the finished item, provided it has bee properly built in the first place, I found it to be great and endorse all the comments made in the earlier reply

Steelfan

[Auzzee]

Hi John, When speaking of the resale value of ferro yachts, I am comparing the cost of purchase with the income from the sale of the same yacht. I realise that the cost of building and fitting out is as high as any other yacht. But, given that very few ferro boats are now being built due to the much lower cost of production hulls, the question of resale is almost exclusively the preserve of second hand boats.

When researching an article on ferro boats, I surveyed owners and the results of sales through two large international internet listing agencies, and discovered that in a relative sense, used ferro yachts have the highest resale value of any yachts constructed from commonly used materials.

I fully understand the loss of value when building and fitting out a ferro hull, but there can be no doubt about the excellent value and eventual return from the purchase and resale of used ferro boats.

David

PS. I had a 46' ferro. The original plans called for 6 portholes, but the builder had not bothered to cut them. I managed to cut 4 and gave up, so I thoroughly understand your comments regarding hatches.

Best wishes. DF

[Spike_dawg]

My view is a little different.

Ferro does suffer corrosion, water intrusion affecting the steel mesh and also reducing the tensile strength of the ferro cement. If not properly sealed and maintained if will absorb water like a sponge, the result is a disaster.

Ferro cement has little impact resistance as it does not flex to absorb energy. Means a lot of ferro boats sink when an FRP boat continues on. Lowest impact resistance of all materials used in boat building. Here it was compared to steel for strength and weight. Like steel it's a heavy, slow boat. It's compression strength that is similar, not tensile, and bending.

Osmosis does not flow from the inside out. That's beyond the laws of physics as the pressure is higher outside the hull. However, the hull must be sealed to prevent rusting of the mesh and does not flow in either direction. Water is asorbed into the cement from the bilge, only if not sealed, and evaporates more rapidly in the top section of the hull.

The below articles are an excellent discussion of materials used in the construction of boats. Also read the conclusion at the end of the first article as to what drives cost in boat building.

http://www.naese.com/materials.htm

http://www.benford.us/articles/boatb...materials.html

It's your decision...cost of a used cement boat is significantly less then a used frp boat, but it's not related to the early problems of ferro. FRP had problems also, especially blistering, but continues to be the material of choice.

[Auzzee]

Hi Spike, I think our opinions are not so far apart at all. As I have stated, a good ferro boat is a good boat.Just as a good steel boat or GRP boat is a good boat. Part of building any good boat is to complete the job, and provided that is done professionally the results are excellent.

David.

[catherine@brittany-gites.]

Many thanks for your comments I shall investigate further. The reason I asked is that there seems to be a lot more yachts in my price range that are larger and ferro than GRP ones.

As I said before I have raced many miles on Glass boats and so feel quite comfortable with them. I have never been on a ferro boat.

[max mariner]

a ferro boat built well is just as sea worthy as a well built GRP boat(some would argue more so).

just figure it out...do what you have to do to make sure it is a ferro boat that was built well. foot for foot, dollar for dollar you get considerably more boat with ferro.

the cheap price is all due to the 'hippyboats' built poorly as auzzie mentioned in an earlier post...they have tarnished the whole lot of them...for better or for worse.

to get THE lowdown check out this link www.ferroboats.com

this is my opinion. my boat is fiberglass. when i was looking to buy i looked at many more ferro boats than boats of other materials...i didn't want to limit myself so i considered all materials...it just turned out the boat that i ended up buying was fiberglass. in many ways i believed a ferro boat was in my future...i was just fine with that.

[Spike_dawg]

Went through the web site. A lot of half-truths there...the article on anodes is just stupid and shows no technical knowledge of understanding electrolysis, and galvanic action.

From the Facts

1) An 8 ton boat is 8 tons...true. Doesn't mean a ferro boat is going to weigh the same as a FRP boat for the same size. Compare a ferro of 40' to a glass boat of 60 feet.

http://www.yachtworld.com/listing/pl_boat_full_detail.jsp?slim=quick&boat_id

=1569836&ybw=&units=Feet¤cy=USD&access=Public&listing_id=1438&url=

http://www.yachtworld.com/listing/pl_boat_full_detail.jsp?slim=quick&boat_id

=1447771&ybw=&units=Feet¤cy=USD&access=Public&listing_id=36664&url=

I tried to get around the same year. Newer cored boats can be much lighter.

2) All different materials. Steel plaster is no different then a caveman spreading mud on the walls...this is stupid.

2a) Osmosis is osmosis. If it was an "advantage" why is the primary discussion the importance of sealing the boat for ferrocement (also FRP, and wood)?

3) A wood constructed boat will sink at the same rate when holed. Unfortunately the point is a ferro boat will obtain that hole long before the wood boat. It's not the speed of sinking but the impact resistance---what caused it to sink. Metals, some woods and plastics are much better.

4) Nothing lasts forever...true.

5) The surveyor isn't the guy sailing the boat. You can get a million opinions from a million surveyors all with dissenting opinions. Bottom line is you choose whats most important to you as everything is a trade off. Cost, performance, ease of maintainence, etc.

8) It's a typo. Earliest known concrete boat is Lambots dinghy in 1848. Earliest concrete boat still in existence is "Violette" built in 1917. http://www.ibiblio.org/maritime/phot...ndex.php?cat=2

Thousands of wood boats much older.

9) During WWII floating wharfs (Mulberry's) were built for the Normandy invasion. These are considered boats as they were floated across the Channel. This is the most DISGUSTING twisting of facts. Notice the use of "TONS" rather then quantity. http://en.wikipedia.org/wiki/Mulberry_Harbour

US boat registration statistics. 1999. 26 to 40 feet, sail, inboard, page 14.

http://www.nmma.org/facts/local/documents/1999%20Registrations%20Summary%20and%20Introduction.pdf

40,421 FRP boats.

Ferro isn't even listed except under "other" 335 boats some of which is ferro.

Funny that they didn't mention fire resistance. FRP and wood burn or melt.

This is not a criticism of ferrocement boats. Just a criticism of the website posted. It's distortion using half-truths.

I believe the first paragraph of max is also true...seaworthy if designed and built properly, like any boat of metal, wood or FRP. Max post...What you get for the price. You may end up with a larger boat as the hull material is less costly and not in general favor by the buying public (for what ever reason)--is this the most important thing to you in your quest? Other factors are it's heavier, slower and difficult to resell. It's all trade offs. You get what you pay for in most cases.