FC hull and bilge oil

[Lacika16]

I went to see a FC hull boat today. It is in dry storage and 40+ years old. Beside few rusty down flows and some damage on the hull, I did see ' wet ' looking spots outside. There was no rain recently and the day was dry and sunny. When I asked the seller about it, he told me about the bilge, which has water/oil mix inside and it is sipping through the FC. Sure enough, when we checked the bilge under the engine, there was a dark layer of oil there.
My question is; is it repairable, after the source of the oil leak is located and fixed and the bilge cleaned? Did the hull get damaged by the oil? Can the hull still be treated and painted?
Any opinion is welcome and appreciated.

[Lacika16]

Here are some photos.

Cruisers & Sailing Forums - Lacika16's Album: oil stains

[GordMay]

Greetings and welcome aboard the CF, Lacika.

[Snowpetrel]

Thats not normal. I cant say I have seen a FC hull do that. Thats not to say it is not whats happened in this case. Whats behind those blisters? Just paint bubbles (common on fc due to lime leaching) or bubbling concrete with rusty armiture under it?

The oil leak seems more like it is from near the bow than under the engine?

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[paulajayne]

That is the bow area and also shows signs of rust. Walk away from it.

[uncle stinkybob]

Originally Posted by paulajayne

That is the bow area and also shows signs of rust. Walk away from it.

+1 + walk fast!

[SF Bay Dude]

That hull is toast. It's unrepairable. A couple down in Mexico where my boat is stored had to demo their boat for the same reasons. Their black iron tank leaked and the diesel penetrated the entire hull from the inside out.

[Cliff Meima]

I assume FC means Fiberglass Cored not the Fish City boat builder. It sure looks like this hull core is saturated with oil, this hull is a total loss.

[SF Bay Dude]

I believe our acronym stands for Ferro Cement…?

[Sailmonkey]

Originally Posted by Cliff Meima

I assume FC means Fiberglass Cored not the Fish City boat builder. It sure looks like this hull core is saturated with oil, this hull is a total loss.

FC typically means ferro-cement


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[Cliff Meima]

Thanks I forgot about cement boats, used during the war and a few pleasure boats that I have seen were made of cement.

[redhead]

Hello, owners of a FC boat here, that was neglected for 30 years. We had an oil leak that seeped through from an inadvertent dumping of fuel in engine room. We got it cleaned up and the boat seems fine now. BUT it was a real struggle and we addressed the problem immediately after it happened.

I strongly suggest you talk to an engineer familiar with concrete and it's capabilities and weaknesses. It really depends on how your boat was built, was it built by professionals or was it one man's dream built in the back yard? The quality of the FC is key. Overall, I'd say if there were other boats you might want to look at them.

If you want the details of our repair you can PM me and we'll fill you in.

Good luck.

** If you go to my profile page and look at the album "Raincoast Refit" you will see a picture of my husband standing next to the bottom, you can see the fuel leak osmosing in the picture**

[captlloyd]

Ferro cement hulls are tough, tough cookies. If you like the boat have someone familiar with this type of construction look at it. Ferro cement isn't that hard to repair also. Can't really tell much from your limited pictures. If this is common throughout the boat it would be a problem, however it could be just some of the steel core material being exposed and bleeding some rust. Find a surveyor familiar with FC. Some people just seem to have knee-jerk reactions about things. Not even knowing what the boat looks like or the price, you could be passing up a good deal.

[billgewater]

I remember a 52 ft ferro yacht that sat on the hard North of Perth in the late 70's for some years with a large "wet spot" on the hull. I believe the wet spot was actually fuel rather than bilge oil.
I understand that the hull was cleaned up and the internal source of the fuel leak was fixed. The hull was washed thoroughly and after drying it had epoxy applied to the outside only, then the usual antifouling etc.. (There is generally no need to paint the hull inside plus paint on both sides may cause one paint surface to blow off).
That boat has been continuously used now and is still in use.
With Ferro Cement you can test for void problems by rolling or dragging a metal tool over the surface. Areas with voids make a distinctively different sound. Voids are generally a consequence of "two shot" plastering where air is actually entrained between tow cement layers. The "avoidance' of "voids" (a truly terrible pun) is a consequence of considerable care during the plastering events. Some voids can be fixed by drilling a number of small holes and pumping in a laminating epoxy resin. If water enters a void it migrates causing armature rusting.
A good test of oncrete quality is the compressive strength. The higher the compressive strength (usually) the lower is the porosity. In old units, 15 to 20 000 psi is good. Ordinary domestic cement mixers usually can't produce this quality as too much water is required to make the mix hydraulic.
Ferro cement boats were once very cheap to make and there are still many sailing around. The cost of cement and mesh and labour has now made them uneconomic. The two oldest working boats are ferro cement and were built in the 1830's by George Lambot in France. Ferro cement vessels, if built properly do not rust, can be immensely strong, do not burn and any damage tends to be localised. However it is dense and does not lend itself to smaller vessels. One Ferro Cement vessel ("Helsal", designed by Joe Adams) won the notoriously competitive Sydney Hobart yacht-race against a large field of international and local boats.
What I can't understand is why anyone would buy a boat on the hard as there are so many floating second hand vessels around that sell for a fraction of replacement and can be trialled prior to purchase.
Nearby our vessel a 56 ft steel vessel that has circumnavigated and has everything needed on board sold for under $50 000 (AUD). Yes, it needs work, but it has everything!
Brand new boats usually require more expenditure than this to make them ready for serious cruising.
Cheers

[uncle stinkybob]

Originally Posted by captlloyd

Ferro cement hulls are tough, tough cookies. If you like the boat have someone familiar with this type of construction look at it. Ferro cement isn't that hard to repair also. Can't really tell much from your limited pictures. If this is common throughout the boat it would be a problem, however it could be just some of the steel core material being exposed and bleeding some rust. Find a surveyor familiar with FC. Some people just seem to have knee-jerk reactions about things. Not even knowing what the boat looks like or the price, you could be passing up a good deal.

the owner of the boat said it was fuel coming out of hull cracks, fuel from spill inside boat, now leaking out the bottom? Knee jerk reaction? naw, not for a boat he doesn't even own yet.