Howdy! I've been living in a tank for a month and a half now, cladding the longitudinal stiffeners (0.5" HY-80) with 11018-M. Every stiffener has at least 3 butt welds in it. Two of them are short, just under the edge of the frames, one of them is long (the entire height of the stiffener), all are vertical butts with 3/32" reinforcement.
Here's the question: Can I clad weld (horizontal stringers) right over the existing butt welds, or do I need to jump over them (skipping them for now)?
I work to WP-1688 for the Navy, and I have asked my supervisor, and my process manager, and other welders, yet no one will give me a straight answer.
By the book, we can clad weld 0.5" HY-80 with 60 degree preheat, 300 degree interpass, but for a butt weld, we need 125 degree preheat, 300 interpass.
The book doesn't specify what to do with an existing butt that is getting cladded over!
Thinking about it, I'm creating a HAZ like a blanket over this whole area, how would this affect the existing through-thickness HAZ in the butt?
Any one ever have issues with this? I don't want to go down with a SubSafe bust, but the damned management won't answer the question!!
PS: I have been skipping over all the butts in my clad sites- pending an answer. This way I can either clad them without heat, or come back later and put up strip heaters.