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Up Topic American Welding Society Services / Technical Standards & Publications / D1.5 Undercut
- - By ccollins Date 04-02-2014 16:21
6.26.1.5 (2008) states that undercut shall be no more than 0.01 when the weld is transverse to tensile stress under any designed loading condition.  How do we know where this is?  I am inspecting girders.  I have asked many people and got as many answers.  Any help to clear this up whould be a great help.

Thanks,
Clayton
Parent - - By jwright650 (*****) Date 04-02-2014 19:30
Clayton,
D1.1:2010 also has the same language in Table 6.1.
Parent - - By SCOTTN (***) Date 04-02-2014 20:43
I have the same problem with D1.1  How would the fabricator know whether the weld is transverse to tensile stress in primary members? By the time I submit an RFI and get an answer, the undercut in question can be removed and the primary member out the door.
Parent - - By jwright650 (*****) Date 04-03-2014 11:05
IN the past, that was the way I handled that too Scott. They said I was too hard on undercut, even caught some flack on here about removing any undercut that you could hang your finger nail on, but I figured better safe than sorry...and we never had time to perform the RFI exchanges. By the time I received any answers back, the piece was hanging in the air hundreds of miles away.
Parent - - By SCOTTN (***) Date 04-03-2014 11:30
I don't like to see undercut, period.  Even undercut that's acceptable looks bad after it's painted.  I can't tell you how many times here in Ga. the paint shop supervisor has called me to the paint shop to look at undercut that I have "let go".  When I worked in SC, our policy was zero undercut, so we didn't have to worry about whether the weld is transverse to tensile stress in primary members or not, and undercut there was rare.  Now that I'm in Ga., I see undercut a lot.  Some of it has to be repaired and some doesn't.  I still don't like to see it, but if it meets the code, I'm told to let it go.
Parent - - By jwright650 (*****) Date 04-03-2014 11:34
When I first took over as the QC MGR at my previous employer, undercut was awful. They had been allowed to get away with a lot for a long time so it took me a while to reign in all of that....but the undercut problems went away with only a few exceptions and the welders knew that they should fix it before they called me over for an inspection so they started fixing it when it happened. Plus some one on one welding education helps the guys not have undercut in the first place when they finally understand some of the causes of it.
Parent - - By SCOTTN (***) Date 04-03-2014 12:02
Same here with my new employer.  During my interview I asked about how the quality was and was told it was good.  During my plant walk through, I saw an unbelievable amount of undercut on tacks, welds, and painted material, and each time I asked.... you let that go? After 6 months on the job we've still not got it under control but we have made a lot of improvements.  The problem wasn't created in a day and it won't be corrected in a day.  I'd hoped by now that we'd have a better handle on it, but it's still a problem.  I know that I have the authority to stop someone from tacking or welding, but I'm trying to choose my battles with regard to not allowing a welder to weld or a tacker to tack.
Parent - - By jwright650 (*****) Date 04-03-2014 12:17
Scott are the welders approachable about helping them with some tips and tricks to eliminate the undercut? Sometimes they are very receptive other times they are not, and then is the organization receptive to having you out there taking their worker out of production to teach gun angle techniques and educating them on the WPS info..etc?
Parent - - By SCOTTN (***) Date 04-03-2014 12:41
Yes, for the most part they are.  Part of their problem is that their supervisor sets the machine for them based on the material thickness and then locks it down.  I have never heard of this being done, but it's done here.  To me, I don't care who sets it as long as it's set within the parameters of the WPS.  I know that welders like to set their own machine, but not here.  Just because the settings works for the supervisor doesn't mean they'll work for the welder.
Parent - By Lawrence (*****) Date 04-03-2014 14:38 Edited 04-03-2014 14:40
Funny Scott... I am going 180 degrees different from you in paradigm.

We can weld any structural steel from 1/8" to unlimited thickness in the flat or horizontal position, groove, fillet, corner.... Girt, base plates, clips, stiffners, rafters... whatever........  All can be done by locking down the solid wire GMAW-sp/pulsed power supplies and giving the operators 20 ipm and 1.5 volts to play with... Nothing more!

I reduced electrode wire usage in one plant by 50% in 30 days using this method.

The welders fought like trapped bobcats when the controls were set in place... Until they actually saw that they were changing spools 50% less........  They didn't like it, but they believed/trusted me after that.

Also also,  WPS parameters I often find provide ranges that far exceed what is actually needed to make the required welds.   This is especially true when PQR's are involved...  A "typical" engineer will generate a WPS with the full ranges *allowed* by the PQR and "trust" the welders to move forward with their dark art... Rather than producing tight ranges and listening to feedback from the floor and tweak as if they were subroutines....... 

If we were bending, machining, painting, roll forming or drawing with dies, the operators would not be given space to do their thing. They would be controlled.

The settings "shall" work for the welder!
Parent - By Lawrence (*****) Date 04-03-2014 12:41
You two !

My life is in your conversation !

Add overwelding ....... stirr liberally

and you have the trifecta of process control issues in weld management!
- - By 803056 (*****) Date 04-03-2014 14:15
That's why we hire engineers to design our structures. They are suppose to tell us the magnitude of the loads being applied, what joints are loaded in tension, which are in compression, subject to fatigue, etc. The inspector is not expected to be a engineer, but he is expected to know when and what questions to ask.

The inspector can often find much of the information on the "S" drawings. All of which supports the belief that the inspector must have copies of the structural drawings (S drawings), shop drawings, and if field inspecting, the erection drawings.

Best regards - Al
Parent - - By jwright650 (*****) Date 04-03-2014 16:23
Al,
I agree with you however,
Unless I'm missing something, I have yet in 30 years working with structural steel contract drawings ("S" sheets), seen any mention of members in tension or compression...end reactions were given at times but no mention of any welds being transverse to the tensile stress.

I can guess simply based upon my (very) limited knowledge, but shouldn't it be spelled out on the members in the plan where this tighter criteria for acceptance of undercut is applicable?
Parent - By 803056 (*****) Date 04-03-2014 17:02
Agreed to a point. The 0.01 inch limitation on the depth of undercut applies to connections subject to cyclic loads. Clause 2.13.3 is the clause I hang my hat on. If the information isn't provided in the contract documents i.e., drawings, project specification, general notes, etc., Rather than operating on assumptions that may or may not be correct, it is incumbent on the inspector to ask the right questions.

For some reasons that I don't understand, many people are afraid to ask questions when they are unsure of the requirements (or directions in the case of driving in uncharted territory). It amazes me when my clients refuse to ask their customers for clarification. They ask me to make the inquiry on their behalf. I guess that's because they know I've already established myself as an idiot, so there is not harm in making myself look silly by asking silly questions.

My protest lives on. I must resist my urge to participate!

Al
- - By ccollins Date 04-03-2014 16:08
Thanks for everyone's imput.  I haven't thought about an RFI but that may be somthing for future jobs 

Clayton
Parent - By SCOTTN (***) Date 04-03-2014 18:06
John and that protest guy,

I have never seen on contract drawings (S shts.) or in any job specs indicating that a nontubular member will be subjected to cyclic loads or not.  As you both know, if the welds are transverse to the direction of computed stress, the backing must be removed and the joint ground smooth and flush.  On the other hand, if the welds are parallel to the direction of stress or the welds are subject to computed stress, the backing does not need not be removed unless specified by the engineer.  All I've ever seen on design drawings or in the structural specs is to "remove all backing".  No explanation.  No nothing.  I would think that somewhere on the drawings  or in the specs there would be something regarding cyclic situations, but I have yet to see it.  Regardless, I always RFI.
Up Topic American Welding Society Services / Technical Standards & Publications / D1.5 Undercut

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