Ferro Cement Hulls ?

[BillAU]

Originally Posted by hummingway

I don't wish to derail an excellent thread but I'm really curious about this. There is a Stan Huntingford who is from Vancouver BC and an accomplished naval architect. He designed my sailboat as well as quite a number of others, most famously the Slocum 43. I've never heard of him building a boat so I'm quite fascinated.

Interesting, I wonder how many of his yachts/boats were designed to be built using FC and, how long has he been designing FC boats
Personally, I'll stick with my search for a well built Hartly, O'kell or a Samson FC yacht and I don't care if the boat was backyard built or not...As long as the builder stuck strictly to the plans and instructions, I should have a safe boat.

I'm sticking with Samson, O'Kell or Hartley because those people/companies have been in the business of designing, building and repairing FC boats since around 1935. Hartley have been in FC boats: Quote from ferrocement.org/ :

Since the first plans were sold for home construction in 1938, it is estimated that in excess of 95,000 Hartley Boats have been built. Apart from 'class dinghys', there are probably more Hartley Boats throughout the world than any other designer. And probably more Hartley ferro-cement boats than all other ferroboat designers added together.
End Quote:
Samson have also been in the game from around the same time, Samson FC boat plans are now being sold by Hartley Boats. And our own Wilf O'Kell has designed great FC boats here in Australia from around the same time as Hartley and Samson. Wilf is now getting to be a bit long in the tooth and has retired to a quiet life in Queensland but there are many of his backyard and Pro' built yachts around Australia. Wilf O'Kell is to FC boats as Jim Brown is to glass/ply Trimarans

Cheers mates,

Bill
Australia

[awab]

hello

Now could be the time to get the ultimate formula for a FC repair job

one more question about the sand

bill proposing basalt sand
other talking about quarz sand.

which one is better

so far the grain should be 1-3 mm.

3 buckets of clean washed sand to 2 buckets of Portland No2 cement to one bucket water

how much pozzolan (fly ash ) ?
This Everdure or white old wood glue sounds good as a bonding agent

3-4 weeks of trying time


any more ideas

thanks

peter

a anwser for bill - I want to be in the south caribbean. No hurricanes there. More chances to get hit by lightening.

[Yachts66]

I certainly concur the oil saturated areas need to be chipped out until they are 100% removed and new cement troweled in to replace it. I've read in many books that integral fuel tanks in FC boats is a nightmare waiting to happen.

This is a good thread and I too have ordered the books, even though doing so from the Jungle here was no easy task.

Regards,

Thomas

[awab]

hello thomas

Info. This boat has no integral fuel tanks. Its steal tanks they started to leak. The boat was stored for 8 Years and rain water came in.

otherwise you are right. integral fuel tanks is not the best idea.

Question. Why do you thinks the oel in the cement is so horrible. Still dont know the reason. To get something to stick on it is perhaps not easy but there are so far I understood epoxies speazially made for this problem. I read under restauration of cement wast tanks they use this stuff.

Does anybody has good info for this problem.

The cement sounds good to me if I hammer on it.
To take this part out would be much more a problem then to buy some speazial even if expensive material. The area is not so huge.

What happens with the cement in contact with diesel fuel.

thanks
peter

[Filofax Senior]

Peter, I have just sent you a PM.

[Yachts66]

Ask anyone who has ever owned or operated a truck stop! Diesel fuel just eats concrete! This is why you will frequently see operators power washing the fuel filling stations which is one way to keep the concrete from breaking up over time. Not a cure, but it seems to delay the inevitable.

This is why concrete fuel tanks are such a very bad idea. Even tanks that are coated will over time fail. Integral tanks in steel boats don't have this problem (they have others, but we won't go there now). So, I stand by my earlier comment. If the tanks leaked and the concrete was saturated in diesel, chip out the concrete, clean the remaining steel and apply a new concrete patch. It's the only way to really attack a problem of this nature.

Regards,

Thomas

[BillAU]

Hello Peter,

I'm still on about the metal used for the section of the hull in this picture.
I believe you said the section of punched steel plate is for a water intake or keel cooler. Well Peter mate, if the builder has used punched plate "anywhere" in the hull construction, then he has made a big mistake in doing so.
Personaly, I would chip-out "all" the FC around that punched plate, (and the oil damaged FC) remove "all" the punched plate and replace the plate with rebar and chickenwire, then put the through-hull fittings in place using the method in the link below.
Here is a link to the correct way of doing through-hull fittings in a FC boat.
By the way Peter, you will find real helpful info' on everything FC on that site section, they are building a Samson FC fishing boat but the same rules apply to whatever FC boat being built. i.e. Good overall penetration of the mortar through the mesh.
That can not be done using punched plate in the hull. Anywhere punched plate is used in the hull will be a weak spot because the builder/plaster can not get good overall penetration of mortar through the punched plate.

Peter mate, you must, for your own safety, get the hull repairs right!

Cheers Peter,

Bill
Australia

[IslandHopper]

Originally Posted by BillAU

Hello Peter,

I'm still on about the metal used for the section of the hull in this picture.
I believe you said the section of punched steel plate is for a water intake or keel cooler. Well Peter mate, if the builder has used punched plate "anywhere" in the hull construction, then he has made a big mistake in doing so.
Personaly, I would chip-out "all" the FC around that punched plate, (and the oil damaged FC) remove "all" the punched plate and replace the plate with rebar and chickenwire, then put the through-hull fittings in place using the method in the link below.
Here is a link to the correct way of doing through-hull fittings in a FC boat.
By the way Peter, you will find real helpful info' on everything FC on that site section, they are building a Samson FC fishing boat but the same rules apply to whatever FC boat being built. i.e. Good overall penetration of the mortar through the mesh.
That can not be done using punched plate in the hull. Anywhere punched plate is used in the hull will be a weak spot because the builder/plaster can not get good overall penetration of mortar through the punched plate.

Peter mate, you must, for your own safety, get the hull repairs right!

Cheers Peter,

Bill
Australia

Nice changing of the script in the link.... Ferro Cement Boat Building Manual Volume 3
but all that link shows is ONE way to do the through hulls on a FC boat, it doesn’t say it's the ONLY/CORRECT way.....

I know (knew) off two FC vessels using the punched steel method, both are Samson’s, one i lost track of a few years ago but the other is sitting in the same yard as my boat up in Bundy, and a very nice NZ example she is....

The point is there is more than one way to skin a cat, and as the particular vessel in question here is the third FC one i know of using this method then obviously it’s not unusual, the only question is has the job been done correctly, if it has then i can see no problem with it as there are many vessels out there that use a “grating” or "grill" type method for through hulls...it’s not unknown by a long shot....

[awab]

hello friends

The punched metal picture is only the intake of the keel cooler. Its to prevend depris getting in. Its not the way how the boat is build.

all the best
peter

[awab]

hello

I found a link for the oel penetration problem
http://www.concreteconstruction.net/...-concrete.aspx

Its still not clear what the oel penetration is actual doing to the FC.

removing the oely cement is a serious impact. If not needed it would be better not doing it.

thanks
peter

[IslandHopper]

Originally Posted by awab

hello friends

The punched metal picture is only the intake of the keel cooler. Its to prevend depris getting in. Its not the way how the boat is build.

all the best
peter

No worries Peter i know what you mean, the two i know of are the same....

[BillAU]

Peter, read this post on FC hull damaged from Diesel.

[Yachts66]

Peter's citation clearly states that oils have a negative impact on concrete. So his conclusion is contrary to his citation. Interesting that.

[awab]

hello

There is no question that this diesel spill is somehow bad. The question is the kind of action needed.

Bad is that primers and paint are not sticking to the cement.
It is not clear that the cement is bad now and has lost his strengh so badly that it has to be replaced.

Sure one of the action could be to replace the penetrated parts. This on the other side is also a major impact.

I will still look for a solution to clean the oely parts.
What are you guys thinking about this products.

Kafko Oil Eater Cleaner Degreaser

there are a lot of other products out there too.

and after cleaning

Epoxy.com Product #201 Epoxy Oil Stop Primer-For Oil Saturated Concrete

Would be perhaps a solution and at least worth a try with out costing to much in time and money.

thanks
peter

[awab]

this message is for bill,
I been reading this post you link to some time ago.
It is right not to build cement tanks for diesel. But this is not my case. I have steal tanks and this tanks have a leak.
In this post they not recomanding to take the oel penetrated parts of the hull out. Only cleaning and sealing new so far I understand.

I have no problem to take the old tanks out. I am looking only for the for the best action to deal with the penetrated parts.

thanks for your effort,
peter