Hi,
I am looking to repair a hole in a very old tugboat hull. She was built in 1887 and everyone refers to her hull as "iron" as opposed to steel. I was wondering if anyone had any knowledge or repair advice for the welding of an insert patch. I'm not entirely sure of the exact metallurgical nature of this type of iron. Can I weld a steel patch to the "iron" and if so, what rod would be a good starting point? My limited metal knowledge tells me that the "iron" has a higher carbon content but it is ductile as the hull plates were rolled and bent to meet the frames along the curve of the hull. Is this weldable? braze-able? and/or should a "iron" patch be used instead of a steel one?
Thanks in advance!
Eric Fischer
frypan115@aol.com
I would suggest that you get an analysis of the material. While this may cost you a little, this is going to give you peace of mind when you strike the arc. (Not to mention when you are in deep water! - Do you intend sailing her?)
If you have this info, let us know and we will give further advice. - Let's face it, who knows for sure what the people used a 120 years back?
Regards
Niekie
Thanks for the help. I'll let you know how the metal tests turn out. I cut off a piece near the repair area (above the waterline!) and I sent out a few emails to some metal testing labs to get a price and to describe the material. Any labs that you would recommend?
My guess is that its not true cast iron as that would be too brittle, but its probably not ordinary steel either as this old boat is still floating! Whats the preferred welding method if it falls somewhere between these two limits?
I do intend on running her again as her diesels are still functioning. I am planning on hauling her out of the water in the next week or two to reinforce some of these bad spots.
Here is a link with some pictures of her.....
http://www.nthp.org/magazine/archives/arc_911/052102.htm
Thanks again,
Eric Fischer
I'm in favor of Niekie's path of thought. Since there are different chemistries of wrought iron, if you find out what you are working with, you can determine the best method and fillers for repair. I personally would match the filler metal with the hull plate, and use either GTAW or oxy-acetylene for the weld repair, additionally confirm the welding procedure with destructive testing. I would also fill the hole rather than install a patch either inside or oustide the hull plate. You can buy wrought iron wire from blacksmith supply houses. If you don't have the funding for the testing. 312ss filler with GTAW will work well as a method of repair. The drawback is a color missmatch, you will see the repair. Good luck, Brad
Eric, have you considered metal powder spray? This is the system that was used to repair the cast iron dome on the Capitol Building in Washington DC. Many companies offer this, I picked mine up from ESAB. It is called a TORCHWELD METAL POWDER SPRAY KIT, ALL-STATE WELDING PRODUCTS. It works particularly well on old cast iron along with all other metals. There is an excellent article in the Welding Journal (I don't recall the month) about this repair job in Washington DC. The man credited with using this technology (as I understand it) was Tom Christ formerly with ESAB he is now with POSTLE INDUSTRIES INC. in Cleveland, Ohio. I was privileged to meet him at an AWS demonstration on this tool. Call him at 216-265-9000 or 1-800-321-2978. I don't know if he would remember me but I did bend his ear for about an hour. Good luck and let us know how it all turns out.
Respectfully,
Mike Sherman
Shermans Welding
Thanks for the help Mike.
I dont know anything about "Metal Powder Spray". I tried a bunch of google searches to see what this was about including trying to find the article you mentioned with no luck.
Once the vessel is out of the water and blasted, i may need to do reapir welds in all positions. Is this something the "Metal Powder Spray" can accomplish?
Kind regards,
Eric Fischer
frypan115@aol.com
Eric, this process has been around for at least 25 years and I am surprised how few people use it. It will do the repairs you need and the finished product will be strong and good looking. Call the number I gave for Mr. Christ, he is a very knowledgable and friendly person and he will undoubtedly be happy to sell you the torch and explain how to use it. What part of the country are you in?
Mike Sherman
Shermans Welding
To my knolwledge........ this particular spray process has been around for close to 60 years. I've been involved directly in promoting this equipment and various powders for over 25 years. It is a remarkable tool for repair of less than high quality iron castings. I also believe it offers better control over deposit placement and thickness than any process I've seen. It can be valuable for certain hardface applications as well. The tug boat industry uses these powders to hardface tug boat sleeves since the introduction of the water cutlass bearing, for example. There is some additional information and pictures on our web site that may enlighten you if interested. They are under the surface engineering/metallising link from the home page. www.usalloysweldtech.com
Cordially,
Steve
"Iron" in this context is wrought iron not cast iron. Once a common material now rare. Its preparation involves hammering a mass of iron (with flux?) reheating in a reducing atmosphere folding hammering etc. The process reduced oxides and removed carbon and impurities. The result was a fibrous mass of nearly pure iron containing a good deal of silicate slag in the spaces between the fibers. If you wire brush a corroded area the fibrousness will be apparent. Blacksmiths readily forge welded this material. It has fairly good corrosion resistance. Hence you still have a hull to repair. I doubt you will be able to get any to make a patch from so you will almost surely have to use steel. Being a buff for old stuff I would be inclined to repair it as it would have been done at the turn of the 20th century that is fit a patch to the inside rivet it on and caulk the joint. If you bolted it that would be Ok also. The material is surely brazable and probably weldable. If brazed and then exposed to sea water galvanic corrosion between the copper in the bronze and the iron in the hull is almost certain. Try this question on a site that deals with blacksmiths like ABANA (Artist Blacksmith Assn of North America) www.abana.org. You are likely to find people with experience with the material.
Further digging found www.realwroughtiron.com. They are in England and sell the real stuff. Follow link to wrought iron advisory council for recommendations on restoration of old wrought iron stuff.
Where is this boat now if you don't mind saying.
Good Luck
Bill
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