Ferro Cement Hulls ?

[Celestialsailor]

Regarding Insurance...It's not about Ferro boats...It's about home built boats. Back yard builders don't have anything like the FAA to have to meet certain standards. Therefore the Insurance companies have no idea of the mesh lay up in a Ferro boat, sandblast and primer method of a steel boat or lay up schedule for a F/G boat. I've built a few steel boats and can tell you that I had little control over the weather building outside. Argue all you want about the boat you have but you could just go sailing.

[BillAU]

As I've said before...I'm no expert on FC boats but...I can not believe any FC boat built, leaving out the twisted chicken wire or some other form of wire netting or steel mesh, even of a kind that is not recommended in the plans, would hold together for a week never mind years. I definitly can not see such a badly built boat (wire mesh left out) staying in one piece after being slung, lifted, transported then lifted again to be placed in the water. I guess wonders never cease. I'll say no more on the pictures.

Bill
Australia

[CSY Man]

some other form of wire netting or steel mesh, even of a kind that is not recommended in the plans, would hold together for a week never mind years. I definitly can not see such a badly built boat (wire mesh left out) staying in one piece after being slung, lifted, transported then lifted again to be placed in the water. I

The boat in the pictures, whether Ferro Cement or Concrete was built in the 70s and have sailed quite a bit as well as having had several haul-outs under it's belt.

I have known the boat and the owner for over 10 years and he kept talking about how strong the boat was and how easy to maintain, etc.
Guess he was wrong on both counts.

When the accident happened I was in the Bahamas around the same island (North Bimini) and gave the previous owner / seller a ride home to Florida on my boat as he jumped ship.

We had quite a few discussions on what happened and how the boat was built, etc.

No doubt there is well made Ferro Cement boats cruising forever with happy owners and at low cost, but this one was not one of those.

What can be seen in the above pictures should be a warning to anybody that any boat, whether ferro or not can be a piece of sh!t and dangerous to your health.

I begged the buyer to get a survey done to evaluate the conditon of the boat, but he refused as the cost of the survey would be close to 10% of the purchase price and too much for the budget.

The boat would probably still be afloat if he had not ran it into the steel-beam holding the marker and if it stayed in sheltered waters, but if a catastrofic failure had happened offshore with no help around or an up to-date life raft onboard, the outcome could have been deadly.
(An Atlantic crossing was in the very near future in the middle of the hurricane season for this boat)

I have also been around poorly built wood, fiberglass and steel boats and would appreciate anybody and everybody highlighting death traps and what to look for when shopping for a cheap boat.

This one was probably the worst case scenario as far as ferro boats (If indeed it was built from Ferro Cement and not from Concrete as somebody suggested..?)

If a few Ferro supporters are too stupid to realize there is some really bad boats out there and instead keep accusing me of posting fake pictures and calling me a troll, then so be it: The proof is in the pictures, no Photo-Shop there and no agenda or campaign going on....

[Yachts66]

Which leads me to ask this question: What is the current thought on the proper mesh to use in ferro construction. Seems chicken wire is out, so what's in and why?

Thanks,

Thomas

[Yachts66]

and.....is rebar in or out? In the pics it looks like this boat was made of just plain HR rounds, is that considered better than rebar now?

Thanks,

Thomas

[mitiempo]

I used to watch John Samson build boats about 40 years ago. At one time I wanted to build a ferro boat but never did.

You need a basic framework which is where the rod comes in. It is then covered with mesh, both inside and out before plastering. The mesh is tied together with wire at close intervals. Chicken wire was common. Jay Benford designed at least one very small ferro boat (20'?) and as I recall it used less layers of a square steel mesh instead of chicken wire.

[Yachts66]

yes, but that was then, what is the preferred method now? Somehow I am thinking chicken mesh has fallen out of favor for something more substantial. Am I wrong? As for the rods that hold the form, is it mild steel rods now or rebar? I'm thinking would hold the cement better. Maybe I'm wrong, this is why I ask.

Thomas

[mitiempo]

Are many ferro boats even built now? Regardless, I don't think the technology of ferro cement has changed much in 40 years.

The square welded mesh I mentioned is stronger, but also thicker and heavier than chicken wire. Mild steel rods would give a fairer hull than rebar I think.

Ferro cement in its day was promoted as an inexpensive way to build a boat. Of course everything put on the boat - engine, winches, sails, etc - cost the same whatever the hull material and the hull is only about 15% to 20% of the cost of the finished vessel. It is also a very labor intensive way to build a boat.

Hell of a lot of work to build a boat with the lowest resale value of any material and there wouldn't be much saved compared to a vessel of another material similarly equipped.

The advantage of ferro cement now is not to build but buy cheap - very cheap.

[Ex-Calif]

I am freely admitting that I am close to clueless on construction methods but at least I am searching for truth!

For anyone who wants to participate in this thread in a meaningful way, please take at least a few minutes to look at the linked page and preferably the entire website. At least don't perpetuate the "friend of a friend of a friend told me you'd die in a ferro boat" myths.

The linked page shows what I would think is a very good creation of the "skeleton." From bigger frames, to smaller frames, to integral floors to both internal and external wire mesh.

There is a terminology to building the "skeleton" which is apparently called an armature. It has frames, stringers, diagonals and mesh/netting.

"Rebar", "chicken wire" and other familiar words to describe the "proper" building of these boats is a complete misnomer that brings to mind broken concrete that CSY man posted and that all of us have seen when a cement building is knocked down.

I am sure there were homebuilders that thought in terms of rebar and chicken wire but that really is not the intended construction method.

I think you can have bad glass, wood boats and steel boats. The methods for determining a bad build are specialized for each type Arguably bad glass boats show up often years later as osmosis blisters. But that is rare today and I would guess that the reason glass has "won out" is because compared to the craftsmanship for wood or the labor required to do a mesh layup like the one linked is too much. Glass boats are laid up pretty quickly in molds.

FC became popular because it was cheap and required lots of labor, something the home builder did not mind investing.

So the big problem with FC is to determine whether you have a structure like CSY man posted or one like the attached link.

Cutting a plug somewhere above the waterline and examining the layers may be the only way to tell. Just do it where a sink drain is needed anyway...

Methods 2

[Wand]

Originally Posted by CSY Man

If a few Ferro supporters are too stupid to realize there is some really bad boats out there and instead keep accusing me of posting fake pictures and calling me a troll, then so be it: The proof is in the pictures, no Photo-Shop there and no agenda or campaign going on....

I guess "stupid" must be me, given in earlier posts by CSY Man I was, in turn, "Sherlock" and "Einstein".

Regarding the rest of CSY Man's post, to me it's all reasonable and considered and helpful; can't imagine anyone would ever contest any of it. These thoughts might have been in his mind before but unfortunately had never made it into his prior posts.

Originally Posted by Ex-Calif

FC became popular because it was cheap and required lots of labor, something the home builder did not mind investing.

Re Ex-Calif's post, I agree that ferro cement's day was when its main opposition was carvel construction vessels. The latter required the skills of shipwrights while the former was within the skills reach of competent amateurs - and thus also within the budgets of the average working man.

But nowadays nothing comes near glass in terms of cost, at least for those who buy off the shelf.

[CSY Man]

I guess "stupid" must be me, given in earlier posts by CSY Man I was, in turn, "Sherlock" and "Einstein".

You started the name calling, I did not.
I posted factual picuters and a few comments, then was accused of posting fake pictures and called a troll.

Anybody in their right mind looking for a FC boat should see what can hide under a coat of paint, get eduacated on the bad apples out there, then move on to find the gems.

Nobody is out to burst the bubble of well made, strong and in-expensive boats, but there is some rotten ones that should be avoided at all cost, hence the pictures.

[Celestialsailor]

In 1996 I was to crew on a paid delivery on a Ferro boat from Santa Cruz, Ca. to Honolulu, Hi. The vessel had been built in South Africa in the 70's. The delivery skipper was also a surveyor and insisted on a haul-out for inspection and paint. Crazing could be seen through the old bottom paint. The yard took a pneumatic chipping/needle gun and the hull began to crumble in the crazing spots. It was a lovely looking hull with a nice interior. Sitting in the water, it would be difficult to tell if the hull had a problem. That same surveyor/skipper bought a 1960's Dutch steel boat. He was chipping at the tar primer in the engine room when a stream of water shot up. To make matters worst, he hauled and plated over the bad plating.
In 1998 a friend of mine bought a steel hull. A Roberts 43. He asked me to weld some gussets in the skeg area. Upon doing so the metal would keep spitting back on my stick like it was contaminated. I asked around until I found someone who had been in the yard where it was built. Apparently it had been constructed of used boiler plate. He sold it and bought a well founded Roberts 43 but would not properly maintain it. He was told repeatedly by the commercial fishing community to zinc the hull every 6 feet. Buy oh no...he knew better. The boat is now dry docked in Mexico because of salt water in his integral tanks. Guess how that happened?
My point is that often times the owners are as bad as the boats. 9 times out of 10, when you try to save a few bucks, your brain goes into denial mode. Yes...you become stupid! And by the way, it's happened to me...
I bought a Wilderness 40 hull,deck for $cheap. I went to add a thru-hull and found the inner and outer skin to be a little over 1/8".
For myself (now), I buy used boats with a long history of good reputation. Sure they have problems. My Ingrid 38 had leaky ports and too small of an engine but a year and a few thousand dollars took care of that. My Blackwatch had soft decks and again 6 months of labor corrected that too. This HR35 I have had an engine problem. $3500 took care of that. For me, if I want to stay in this lifestyle, I have to do it in a way that I can afford. But I have to be smart about it too.

[clockwork orange]

Am i the only one participating on this thread who has actually built a Ferro boat? maybe. Ok, heres my background for those who dont know, i built a Hartley RORC 39 for myself back in the early 70s while i was an apprentice boatbuilder building cold molded boats, foam core boats and fitting out glass hulls by day. I chose Ferro for the usual reasons of low material cost and the fact that i could build it somewhat exposed to the weather, i built the shed which it was suspended from with a roof,one sidewall and one endwall only on the exposed sides, during the 4 years it took me to build it i was totally immersed in the Ferro culture and helped out on plastering days on many other boats so i do know what i am talking about. I have since built many boats in many different materials and am not biased in any way toward or against any material, you can build very good or very bad boats out of any of the common materials and methods.
Ok,with that out of the way,i can say that i have never seen a ferro boat that used rebar as i know it in the structure, hard drawn wire is what was typically used, in the case of my boat it was only longitudinal stringers 2" OC of 5 Gauge which is less than 1/4" dia. Chicken mesh was the most common mesh, 1/2" x 22 gauge galvanized mesh for most of the builds i saw. It was left outside to oxodize before use. Larger boats would use diagonal stringers as well as longitudinals,also about 2" OC. Typical was 4 layers of mesh each side of the stringers. Typical core samples on my boat measured about 11/16" thick. On a larger boat with diagonals i would expect about 1".Some designers prefered welded square mesh which may or may not be "better" than chicken mesh, Hartley speced chicken mesh and probably more of his designs were built than all the others combined and have stood the test of time,at least the good ones. That thing that CSY man posted bears no resemblence to any ferro build i have ever seen and i have seen a lot at the armature stage.
My feeling is that when building in ferro you need to pay attention to your steel to mortar ratio just the same as composite builders do (or should) with resin to glass ratios, you want a nice densely compacted armature with only enough mortar to "wet it out" without void and provide a thin cover over the mesh, no more, you need to do your fairing in the armature,absolutly not with the mortar. Mortar has great compressive strength but not much else. My then wife and i faired our armature largely at night where we could take advantage of lights and shadows as well as,the usual fairing battens.
Steve.

[Wand]

Originally Posted by CSY Man

You started the name calling, I did not.
I posted factual picuters and a few comments, then was accused of posting fake pictures and called a troll.

Well, well, how things change. Ozskip has shown in the accompanying thread that Alan Wheeler way back in 2008 did indeed give you the correct lowdown on that vessel and that, in response, you wrote "bingo".

You knew full well when posting those pics the other day in this thread with minimal comment - just enough to imply, even under further questioning - that this was a normal if poorly built ferro boat that suddenly went kaboom.

You knew full well that the vessel had been bleeding rust for years and that the previous owner had simply applied cosmetic fixes.

None of this you related at all - you just posted those images and the sole purpose can only be as a troll, a lie, to get a reaction - and the proof is there for everyone to see.

For these sites to work, posters ought to be striving for accuracy and they ought to be honest - the fact is you are not and it has thus been proven.

As I said earlier, it must be how you get your kicks and other posters would be well wise to simply ignore you.

[Yachts66]

WOW!!! So, chicken mesh is still in and rebar is out! Good to know!

Thomas