Historical Iron Boat Hull

By frypan115 Date 07-22-2002 18:02

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

By Sean

Date 07-24-2002 01:49

Dear Eric,

The repair will be more effective if you take the time to identify the material, particularly if it is cast iron.

My recommendation would be to first identify the material. Some of our local NDE companies can perform on-site chemical analysis. This will determine the weldability of the material. If they don't have the equipment to do the on-site testing take a small sample of the material and have a chemical analysis and hardness testing done. If the chemistry indicates that it is a cast iron you should have microscopy done to identify what form of cast iron it is. From there you can choose your welding process and consumables.

I'm not sure how big of patch you need, but I believe that there is an AWS standard for ship repair which will tell you how to cut out the hull and the sequencing for the new insert. I'm not at the office right now so I can't tell you the standard's proper name.

I hope this of some help. Good luck.
-Sean