Hull Interior - Tar-like Bleeding

[bushymac]

Hello all, I was hoping that someone here on this forum could help me with some info. I have a Samson designed yacht, about 20 years old, and the hull is an epoxy slurry layed over a steel core, along the same principle as a ferro cement. From all accounts/information I have it is an epoxy only(with micro ballons etc), not a cement/epoxy mix.
In a couple of places on the interior of the hull, there is some sticky black substance that has dripped down the paint work. It isnt much, like a bead of water would leave as it runs down a surface, but if it is wiped off, it returns a few weeks or months later.
I am guessing it is coming from the steel core of the hull? but would love some feedback about this, as I am a little worried what it means about the integrity of my hull in these spots or overall. Any info would be appreciated and most welcome.

Cheers

[bobconnie]

Ive been looking at a boat of the same style and construction. And I saw no indication of this type of stuff !! But I would like to ask you if the hull has held up for you ? any blister problems ?? and like that !! Love the boat but never in my 50 + years of boating have I seen a boat bilt this way !! I thought it was ferro when I first saw it ! could not believe it was glass til I inspected it !! Seemed hell for stout!! just wondering how you like yours ??

[bushymac]

no, there is no blistering because it is NOT fibreglass...epoxy is very different...being as close to water resistant as you can get, while fibreglass is not, hence the osmosis. I am very happy with the hull apart from a little worrried about the bleed I posted.

[Nemo55]

Is it possibly Gasket sealant between inner constructs (decks, or bulkheads, cabinetry ?) when this stuff breaks down or gets too old, it will act as you are describing.

[bushymac]

No, I dont believe it is any gaskets doing this...the bleed spots in question are far removed from any such areas, but thanks anyway

[neilpride]

If you are out of the water, Grinder surgery i guess, probably is the steel grid rusting inside, you see any evidence of expansion in the area?

[bushymac]

No there is no expansion in the area, and everything seems to be sound. I would have thought if water had got into the core it would have rusted and there would be rust stains (shrug) anyway, it is still in the water so any grinding will have to wait

[Wotname]

Any chance it is tar epoxy bleeding through a epoxy barrier coat that is a little to thin in places. I understand that tar epoxy although a popular steel coating a couple of decades back, is now banned due to unacceptable health risks. It will bleed just about anything except a decent epoxy barrier coat.

[Blue Stocking]

bushymac, afraid I can't help with any advice, but am REALLY interested in any info you can supply (please) on the origin of this system, particularly the filler product.
My only experience with this epoxy matrix material was in the middle 60s, where it was applied and beautifully faired, over the steel hull plating of an Abeking and Rasmussen built, Luders 44 sloop.
Stuff was hard as h*ll when cured, has tremendous tensile strength and impact resistance.

[bushymac]

Thanks for your imput Wotname...I can only hope it is something like what you suggest...

[donradcliffe]

Sound like improperly cured epoxy and water--I have seen the same stuff oozing out of fiberglass/epoxy repairs.

What does it smell like?

[bobconnie]

Bushymac, Thank you for your reply!! we were just worried about the material of the boat ! I now feel that we will have a survey on it and go from there !! We really lke the boat, have liked Samson boats for years but Ferro was just not for us !! This style of boat fits our needs ! Do you by any chance know who was the bilder of these boats ?? I was told there were 3 or 4 of them bilt, no big thing was just wondering ! Please keep in touch as we maybe the only ones left with these boats !! We are in Louisiana, and also whats the draft of yours?? we were told this one was 5 1/2 ft?? just wondering as we have 6ft at our dock !! LOL thanks again!! Bob and Connie

[hellosailor]

bushy, i don't think there is anything such as a "steel cored" hull. Either the hull is steel, or it isn't. There's nothing to do with "coring" in steel hulls.

And steel doesn't weep anything black. AFAIK uncured epoxy doesn't weep black either, not a real true black.

What is common, is the use of gasket sealer (not gaskets, but gasket sealer) which is a coal tar type of material, a thick BLACK or nearly black goo that has been used for at least a hundred years to coat steel and other material to prevent it from rusting. The stuff never really cures or solidifies, which is why it never flakes off and protects very nicely. Until it flows off, eventually, and needs recoating.

It sure sounds like someone used coal tar or a similar product to "protect" something in what sounds like a simple steel hull. And then someone added an epoxy layer inside the boat, making it impossible to access the coal tar, which is now simply bleeding through it.

Yes, the stuff is very good at bleeding through.

Similar products are sometimes used as a cheap way to undercoat car bodies to prevent rust, although those are usually designed to harden up. If you want to solve the mystery, you'll have to clarify "steel cored" and peel away the interior liner to find out what is coming from where.

[bobconnie]

hellosailor. your a little wrong on this perticular boat ! there at least 4 of these epoxy over a steel framework, all bilt in the 80s they are a Samson model made from epoxy and glass beads over a steel core somewhat like a ferro cement boat! Im in the process of buying one right now! The current owner has had the boat from new. He now has Altzhimers, and has been unable to use the boat for 5 or more years, Ive talked to him, but his memory is a little faulty, and has not been able to remember the bilder I wish I knew who bilt them as they are really something ! Bilt like a Tank, but not heavy like a ferro boat !! The one Im buying has no weepage like Bushymaxs has but I really dont think it would be a big problem! I have looked at some of the core samples of this boat and it's hell for stout !! just saying I had never seen one in my 50 +years of sailing and owning boats ! till justa couple of mos ago !!

[hellosailor]

Bob, it sounds like a steel framework (armature) that someone has plastered over with epoxy/glass. If that's the case, calling it "steel core" would mean that a ferrocement boat should also be called "steel core" since it is also built over a steel rebar framework.

Perhaps the folks who build 'em prefer to call it that, but I've never heard the term used in any conventional reference to conventional boatbuilding. I guess if they invented something new they can call it anything they want to, but does that make a conventional wood-framed home a "wood core" building? No, it is still framed, not cored. No doubt you've met steel cored fire doors? Not the same kind of "core" job, is it? I'm not buying it, no matter what the inventors want to call it.