Iron Hull Repair

I have a 73' Dutch Sailing Barge built in 1893. The hull is rivetted iron. In the 70's it was fiberglassed over with about 3/8" fiberglass. I have it on the rail and there are two cracks in the fiberglass and they have allowed water in between the fiberglass and the hull. Corrosion has occurred and the swelling flaking has delaminated more glass so that now there is an area of about 75-100 sf. of corrode hull and delaminated glass. I am cutting off the fiberglass and will repair the hull. How best to repair iron. I had a metallurgist which said the hull was hamered iron. He had suggested not welding as that would set up stress cracks. Another idea is steel plates thru bolted w/ teflon coated bolts. The problem there is the inside is concrete ballasted so the concret has to be removed. The previous owner did the concrete in most parts of the boat the fiberglass works however when it fails it can get out of hand fast. That is what i have here. Any suggestions?
Please cute comments about torpedo practice do not help. Failure is not an option.

 

Hrm... glass will do that to iron, I suppose.
I tend to agree with your metallurgist that welding would be difficult if not impossible to do without setting up more points of potential failure.
I don't suppose you'd be able to get more iron plate and iron rivets?
Steel plate is an option but I'd keep a close eye out for galvanic corrosion issues; steel does have a fair bit of carbon in it.
Removing concrete ballast would be a major pain but unless you have a welder who knows how to do this without screwing up the iron's microstructure too badly, there might not be another option.
I wish your dilemma were simpler....

 

welding issues

I had a neighbor who is a metallurgist test the hull and I remember him saying that it was close to steel but it had a layered structure because it had been hammered. I do not know many rivetters.
Do you know what a welder would have to do to weld steel to the iron? What does welding do to iron vs steel that sets up stress?
I need an education quick! Thanks.

 

I think certain irons need preheated before welding.

You have a dilemma, in that anyone with riveted iron hull construction experience, is most likely getting well on in years. Not many that old (excluding Berg) frequent the internet.

Might do you well to search the above types out by more conventional means. Steel ship yards and such might be able to lead you to such an individual.

I remember your images from another thread. Beauty & character for sure. Hope you find a viable & functional solution.

Tim

 

Riveting Iron

What you have is mainly a time and labor problem, not a technical problem, as most of it is removing the fiberglass and concrete.

Riveting iron was also used in boilers, bridges, steam locomotives and skyscrapers.

I'd start by contacting museums that specialize in those areas. There are also people who collect and restore steam locomotives and tractors that might be able to give you some guidance on riveting techniques.

 

RF's museum suggestion is good. Another source would be someone who has done this on an iron hull. About 5 years ago, someone purchased an 1887 iron hulled tugboat for restoration in the Hudson River - NY Harbor area. I don't know the owner's name, but it was mentioned in an article by Don Sutherland, a well known marine photographer and writer. He does a lot of writing about the restoration of old tugboats, which have the same coastal water environment as your vessel. You can reach him at
ssuthe7880@aol.com . He might know how to reach that owner or someone involved in that iron hull restoration.

 

Thanks everybody,
right now I am leaning toward mechanically bolting new plates and the covering w/ fiberglass. The concrete does have to go. I really can't weld and rivetting is a problem. No one will see the repair so bolting may be the solution. Oddly enough I am pretty sure that it is a steel plate repair that is getting the brunt of the corrosion. At a joint it seems one plate is relatively unscathed and the other is badly corroded. I am told that the graphite in the iron acts as a cathode to the steel as an anode so the corrosion attacks the steel. Once more fiberglass is cut out I will have a better idea. I think an earlier repair had a bad fiberglass joint that cracked and then the water on steel was off and running.

 

after reading this and hearing about removing concrete pulling the old closed cell foam out of my boat doesn't seem like such a bad job Good luck with your boat- sounds like a really fun project!

I'd like to see the pictures of it too if possible- got a link?

 

Here is one of the images from his previous post. Nice boat.

Tim