Cladding 1/2" HY-80 and existing butt welds...

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.

Thank you!

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Serial # 19781010

Default to the more stringent requirement. For example, in this case if you were cladding alone, 60 F preheat would suffice. If you were doing butt welds alone, then you would require 125 F preheat.

So, preheat to 125 F and maintain the 300 F interpass.

But I would still inquire about a specific weld instruction in order to clarify any gray areas.

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Serial # 19781010

Hello, and thank you for responding! I'm working at PSNS, on 2nd shift. I would have thought that my Process Manager would have either called or more likely e-mailed our Code 138 people and that we would have gotten a response by now (it's been 5 days).

I think part of the problem is that nobody wants to put heat on in this tank until the last possible moment, when we will need it for the frames and the Pressure Hull. It's small, tight, and the ambient is already 80 degrees. This is also the most "paperworked" tank that any of us have ever seen outside of an RC. The "package" is over 3 inches thick!

Dayshift has asked for so much technical direction that now we are stuck, and need yet more direction to clarify our existing directions. You simply would not believe how many 20-B forms we have.

Technicalities aside, do you know what (if any) damage would be done by simply continuing a single layer clad over an existing butt? We're not creating a haz that runs through the thickness of the plates....

If you have any contact with your 138 people, what have they said?

I'm getting the impression that this is the type of question that one doesn't ask here. Perhaps because requiring heat on the butts would dramatically slow down production? Risk of burns goes way up (small spaces- I'm 5'11" and 148 lbs, and I have a hard time turning around in this tank between stiffeners)?

Perhaps there -is- no good reason (based on physics, not paperwork) why we should put heat on?

I know I don't want to, but I will if I have to....

Thank you, Tin Lizzie

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You can be technically correct, 100% right, but administratively wrong by not following the local written "law" or procedure.

You can imagine if you get called on the carpet, for example, to explain as to how you came up with the method, no matter how correct, and you reply, well, I posted to the net and that was the response that I got from an ex-138 type...

After the laughter dies down, yes, they will fire the rest of 138, and you along with them. Just friendly advice.

We used to have a welder who relished in challenging our weld auditors. (I believe the auditor transferred to PSNS). He thought he knew the procedures inside out. We used to pull the certs of violators and make them take a written test, etc...

One poor sap got caught so many times they made him like a permanent X26 procedure auditor, if I recall.

Cladding a single layer over a butt weld cannot be that detrimental, but again, heed my advice and go to the more stringent extreme. Preheat IAW the butt weld requirement, 125 F, UNTIL YOU GET WRITTEN INSTRUCTIONS TO REDUCE TO CYA.

Consider the case of "excess reinforcement". What do they make you do if you exceed the height reinforcement? Grind it down?

Again, I can just hear five 138 types and you will get five different arguments about this issue.....

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Serial # 19781010

Good advice, thank you! Yeah, I could imagine the arguements pro and con, but you are right- until a WPS is written, signed off on, and in the TGI, I'm stuck following the current regs.

I just wish to hell and back that codes 250 and 138 would actually test some plates for this scenario, so that we could have a sound reason why we have to increase our preheat. Lord forbid that they do any such thing, though. If this made sense, I wouldn't be in shop 26!

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