Saturday, January 10, 2015

Those Canucks take their welding seriously

I know what you're thinking, another early Saturday morning question.
I've been looking at the requirements of obtaining a CWB inspector certification. Am I seeing this correctly? A CWB inspector can apply for a CWI by reciprocity by nothing more than an application and fees. But a CWI who wants to be a CWB, in this case a level 2, would fill out the application, pay fees, and still have to take an exam?
Doesn't strike me as "equivalent" or fair.
Level II VT, PT, MT, UTT

Your assessment is correct.   For a CWB to apply for a CWI it’s just a fee and some paperwork.  For a CWI to apply for a CWB it’s a test.  Those Canucks take their welding seriously.
I was the Quality Manager in a pole manufacturing company that was CWB Certified.  Every 6 months I had to hire a CWB engineer to audit my organization (and it was an in-depth look at our welding).  There were a lot of hoops to jump through, but if we wanted to sell power-line poles in Canada it was a requirement.
I was also a contract CWI for a boss that was Canadian.  Anytime I mentioned my past work as a Welding Engineer he would go ballistic.  Calling yourself a Welding Engineer in Canada means you’ve met specific requirements in education and testing and if you referred to yourself as a Welding Engineer without meeting those requirements you could go to jail.
Some of the things I liked about working in a CWB shop: 1.) Welders had to retake their Welder Qualification Tests every 2 years.  I believe that helped maintain weld quality in our shop. 2.) Welder Qualifications were given using a Bevel Groove.  The first pass was a Fillet Weld of a specific size up against that square edge of the Bevel Groove.  The fillet had to have a restart in it. The location of the restart was marked, and 1 of the 3 required bend coupons had to contain that restart.
One of the things I didn’t like was that they consider FCAW and GMAW with a Metal-Cored wire (MCAW) the same process (for welder qualification purposes).  The Welding Engineer in me (said quietly so as not to be heard across the MN/Canadian border) sees these processes as requiring different skills.
When working in a shop that requires compliance to CWB and AWS this FCAW/MCAW thing reeks havoc.  In fact, when I showed up for my first week at this pole shop I learned that All of the Welders took a FCAW test to get their job, but the shop ran about a 50/50 mix of FCAW and GMAW using Metal-Core.  From a CWB perspective this was no “Biggie”, but from an AWS perspective (which was about 90% of what they did) no Welders were qualified for GMAW (and not one of the 4 CWI’s that worked there seemed concerned).  What a mess!
The way I turned that around was by using the CWB 2yr retesting requirement.  I gave MCAW tests, had them evaluated by the CWB to Canadian standards and evaluated them myself as a CWI to AWS standards.  At 6 month intervals, over a 2 year period, those Welder Qualifications were brought up to speed.
If I was an independent contract CWI I’d probably pursue the CWB route, but if you work in a shop that’s considering bringing in CWB work then CWB/CWI reciprocity is the least of your worries.

Saturday, January 3, 2015

Fillet Welds on Corner Joints

I have a question regarding D1.1 code.
My question is regarding the corner joints in the plates encompassing the columns. They are calling them Fillet welds, yet there is not any faying surface. D1.1 says a fillet can have up to 3/16ths misalignment (with certain stipulations) which is effectively is making the joint an open root CJP.
They are using a ceramic backing that (desired because of the tight fit around the square column plus the misalignment) is reducing the theoretical throat greatly. Now they are having substantial issues with cracking threw the throat, which isnt surprising.
My issue though is with the joint design; Im inclined to say it is not a fillet weld, but I cannot find a code reference to support that claim. And I cannot find a prequalified wps and joint config that in any way resembles this joint PJP or CJP groove.
Am I missing something in the code that resolves this? Specifically any denominational requirement for the length of faying surface on fillet welds? What course of action would you advise?
Thank you for any assistance,
- Caleb

I'm not sure of the plate thickness, it looks (from the photo) to be about 3/8”. If that's the case these 1/4" welds are undersized. That said:
This is a common Fillet weld on a Corner joint. If you have a copy of AWS D1.3 Fig 3.2a you'll see a picture of it.
Questions I would ask…
Does the shop/contractor have a WPS for welding this?  The fillet looks to have been done vertically down. This would require testing. What is the process used?  It looks to be GMAW-S. If so, this would require testing also.
I'm sure your cracking is due to insufficient throat. You can fix that by requiring multiple passes.
Here's where you should go with this…
Ask about the WPS and the process. If they are not in compliance, take out a rubber hose and beat them until they are (that’s a metaphor for fix that first 😊).
Ask the engineer to change the weld call out to:
Weld size = T (remember, T is thickness)
Require a Convex contour (that will insure the throat size)

That should do it.