Ferro Cement Hulls ?

[smallyachts]

osirissail -

You are correct regarding the use of stainless in a water rich / oxygen deprived environment.

However if it is buried in the Fer-A-Lite there will be no moisture present as long as the outer barrier coat is maintained.

There is not a moisture penetration issue with Fer-A-Lite as compared to a standard ferro cement constructed hull.

Since there is no moisture in the plastering material, and the material does not promote moisture penetration, my guess would be that the armature in their hull is as solid and strong as the day it was laid up, which can be verified by a simple hull boring.

We think of it as steel reinforced fiberglass constuction or a plastic encapsulated steel hull.

[AuzzieM]

Hi,
I had a similar issue with my Hartley Queenslander, of damage in the anchor well area.. I repaired the area by removing the ferro back to nice white/grey coloured strong material, and cutting back all the rusty armature till it was at a position of no damage, and cleaned it to a bright finish.
I then placed 1 layer of 4mm galv square section (about 30mm x 70mm holes) wire tied to the original armature and stem, and another layer inside of that (off-setting the holes) and overlapping the hull by 100mm. I then plastered with Ramsett Epxoy Grout, following their instructions to the letter and like another guy has written, it sticks REALLY well, it is designed for concrete and doesn't mind minor moisture content. After plastering I painted the inside with the black bitumin type paint that I purchased from Supercheap and is painted on the under body of cars, (fibre reinforced to stop stone impact damage), then lined it with 15mm thick holed rubber door mats, cut & cabled tied to form the inside shape.
This is stronger than the original now, very happy... But if I did it again I would not use the GROUT, but PASTE, the grout is designed to flow into every nook and cranny and not hang up..and I had to use formwork. Several Companies in Australia have the good quality Epoxy Paste designed for concrete repair, Ramsett, Parchem, Sika to name a few.
Another thing I would do next time is to put a couple af layers of half inch galv bird netting on the outside it will hold the plaster in better, gently push one in from the outside first and fair, then after the first layer is cured, push from the inside untill all covered. Unlike cement you don't need to do all the epoxy it one hit, as it sticks very well to itself, just need to carefully work the second layer in, to eliminate voids
A lot of ferro boats go here and I think it is the chain impacting on the #1 frame in the well, chipping away and eventually exposing the armature (I had evidence of this), so when you have finished I suggest rubber mats and other protection as required.

[caps38]

Hi
We have a ferro yacht a samson seahawk. She has circumnavigated the world twice and we are refurbishing her at the moment. She was built in 1973 and is 50feet we are very pleased with our purchase and have good history and survey and pictures of it being built.
regards caps38

[Yachts66]

Do any of you Ferro guys know anything about ferro diesel tanks? I've been told they are very bad and if you have them they should be cut out and steel tanks put in their place. Would anyone care to address this issue?

Thanks,

Thomas

[AuzzieM]

Originally Posted by Yachts66

Do any of you Ferro guys know anything about ferro diesel tanks? I've been told they are very bad and if you have them they should be cut out and steel tanks put in their place. Would anyone care to address this issue?

Thanks,

Thomas

Thomas,

My tanks are steel and separate from the hull, in the book "Ferro-cement Boats" by Colin Brookes it mentions diesel damage to ferro hulls on integral tanks where the sealing has failed.
So I suppose if the sealing was OK and you replaced your tanks with steel, you might get away with a clean out out the area, If the diesel has seeped into the ferro, then you may consider replacing that area with new..
I still like ferro after owning mine for 3 & a half years,... halfway through a winter cruise to the Barrier Reef in Australia and will look for a larger one (maybe a fijian or similar) on my return to Brisbane in Sept/Oct.......

Anyone got one for sale??

Cheers Maurice

[waterworldrob]

I have steel tanks on TOKETEE. I wonder if it would be possible to cut and opening it yours to allow the insertion of a fuel-bladder made of nitrile? seems way easier than tank removal, and it could be easily ceaned or replaced if ever necessary

[pdbms]

The issue you may have is that the tank is, more than likely, baffled. This would prevent you from installing the bladder.

[caps38]

Hi
We are considering putting in diesel tanks from Atlas tanks made from polyethylene for marine use. They have standard sizes and will also make custom to fit.

We already had black steel tanks which were rusted and had black growth but have not discounted using steel just not black steel.

Has anyone used polyethylene for diesel. We are keen on the atlas because they are seamless.

[Yachts66]

The black growth has nothing to do with the black steel. It's more than likely a organism which lives in the layer between the water in your tanks and the diesel fuel floating on it. You can treat the tanks with a diesel biocide to kill the bugs, but you really need to polish the fuel (filter it) with 2 micron filters to remove both live and dead buggies. If the tanks have clean-outs consider opening them up, thoroughly cleaning the tanks. Steel tanks should be painted inside. Ameron 240 is one epoxy coating that works well on fuel tanks and is also approved for that use.

Regards,

Thomas

[caps38]

yes we knew it was a bug in the tanks. The tanks really need replacing as they were also badly rusted and 37 years old. We also want to get larger ones put in.
Also have you heard of epoxy and copper powder mixed together to seal the ferro hull not as an antifloul but put on after two coats of expoxy. We were told this will really give the ferro good protection from barnicles breaking through the antifoul. We noticed when we cleaned the hull that some barnicles had penetrated through to the hull. We have heard of using this as antifoul but not as coat to seal the hull.

[Yachts66]

Interesting idea. How much powder per gallon of epoxy?

Regards,

Thomas

[Pete7]

Caps, copperboat antifouling paint (copper suspended in epoxy has been tried over this side of the pond. Some impresive results claimed but we cant' use it as we bottom out in the mud at low water which stops it working.

multiseason antifouling 10 years protection hard wearing copper filled epoxy resin copper antifoul

We replaced an aliminium diesel fuel tank with a plastic one (from Vetus) in a previous boat, big advantages are it didn't cause as much condensation inside the tank and being translucent you could see how much fuel was left it in the tank. We will replace our current steel tank with another plastic tank in the next couple of years, although may end up with a custom one. This is a UK company but you should be able to find someone similar.

Custom Boat Tanks | Tek Tanks

Pete

[smallyachts]

You may want to research the copper laden paint idea directly against the ferro-cement hull.

I will see if I can find the link that I read this on. I think it may have been on ferro boats site.

But I believe it is not recommended to put a copper laden paint directly on a ferro-cement hull. Something about electrolysis going rampant with reactions between the copper, the steel in the armature and the composition of the cement.

It is my understanding that it is okay to use that type of paint after a pure epoxy barrier coat has sealed the hull first.

[smallyachts]

I found one of the links where I read the issue of electrolysis in regards to applying a epoxy/copper paint to a ferro cement hull.

8. PREPARING AND PAINTING A FERROCEMENT HULL

There seems to be alot of differing opinions out there regarding the use of the material.

The biggest problem I think is the fact that it completes electrical "circuits" when painted over all of the metal fittings that you spent time and effort isolating from the steel armature of the hull.

Of course if you properly seal the hull, and do not allow any of the copper laden paint to directly touch on any of the fittings, it may be ok.

Or then again, you may have just produced a large but ineffective battery bank

[caps38]

Hello Caps38 here!

Yes you are correct it would cause electrolysis. We were going to put two coats of epoxy on first but we certainly need to do more investigating. We have some repairs to do in the hull and want to make sure we do not only the repairs properly but that the hull is sound when we finish. Interesting we havent come across anyone with a Samson Sea-Hawk which is how it is written on the plans we were given. We would be interested if anyone has a yacht the same or knows of someone who has one. Its looks very similar to Samson C Duece.