Monday, July 10, 2017

The Same Welder Quals Over and over and...

Paul,
Why do companies require so many different test from one place to the next if your always doing the same kind of work?
Jacob M.

Jacob,
Certain tests are required to qualify you for the correct material, process, thickness and position.  The code you're welding to will specify the test requirements.  Often, these tests can look far different than the actual welding you'll do in production or on the job site.
Each employer is responsible for their Welders qualifications, so if you hop from employer to employer each of those employers are required to give you the required tests.  The employer is held liable for your qualifications, so they would not typically accept a qualification from another employer.

PWC

Tuesday, July 4, 2017

Check That Liner First

Jason G - Is it acceptable to use .045 wire with a 1/16th contact tip?

Jason,
That's not a "code" question, that's a "weld process" question.
My answer:  You should not have to and there is good reason not to.
The contact tip is the location where current from the electrode lead is going to transfer to the actual electrode (wire).  The larger diameter the hole the wire is passing through, the poorer the transfer.
Of course, a contact tip that is too small a diameter will lead to feed problems, but it would not be common for a contact tip manufacturer to manufacture 0.045 inch diameter contact tips with too small of hole.
You may find yourself experiencing feed or burn-back issues and thinking that increasing tip diameter should solve your problems.  Doing so may help minimize a symptom, but you have not corrected your core problem.
The first place I'd look for solving THIS problem is the gun liner installation.  Gun liners, when installed, need to rest tight against the defuser (part holding the contact tip).  Many mistakes can be made when installing a liner.  One of the biggies I see, is cutting it too short.  A short liner leaves a space between the end of the liner and the back of the defuser.  This space will allow the wire to wobble before entering the contact tip, leading to burn back.  It will also leave space for the buildup of metal shavings which can eventually become the "point of transfer" and lead to burn back.
Someone who does not understand the proper technique for installing a liner will change the liner once problems develop and then not realize they have just set themselves up for failure and frustration.
Always follow the gun manufacturer’s instructions and before cutting it to its final length keep these tips in mind:
1 - Keep the gun as straight as possible.
2 - Mount the gun securely onto the feeder.
3 - Calculate the length the liner needs to extend past the end of the gun (often the gun manufacturer will list this dimension).
4 - **MOST IMPORTANT** Before cutting the liner at that dimension, apply pressure pushing the liner into the gun (you'll find the liner will easily move 1/8" - 3/16"), hold that pressure, measure and cut.
5 - **EQUALLY IMPORTANT** File down the bur formed by cutting.
Give that a try.
PWC

Sunday, March 5, 2017

Find Your Resident Experts


Hi Paul,
Quick question. Can a CWI write a welding procedure just being a CWI? Or does the company he works for engineering department have to give him the power to?
Unknown
Whomever you are,
Becoming a Certified Welding Inspector (CWI) does not, in-and-of-itself, qualify you as the one who writes Weld Procedures (WPS).  Codes and standards will require that we use “Sound Engineering Judgement” and AWS QC1 - Specification for AWS Certification of Welding Inspectors states “…the CWI shall: 11.2.1 Undertake and perform assignments only when qualified by training, experience, and capability.”
A designation as CWI (or CAWI & SCWI for that matter) does not qualify you for anything outside the scope of visual inspection of welds/welding.  CWI’s come in all shapes and sizes.  Some are Welders considering a career change, some are Engineers, Purchasing Agents, Lawyers, Supervisors or NDE Techs (nondestructive evaluation).  The list is pretty much endless.  All of those backgrounds can make great CWI’s, but none of those backgrounds make the individual an expert in the field of Code Compliance. 
Back in 1993 I was a 3rd shift Welder who dreamed of bigger things.  My employer gave me the opportunity to take the AWS Seminar and CWI Exam.  Shortly after passing the Quality Mgr recruited me to his department for a short-term project of reviewing the companies ASME & AWS WPS’s, PQR’s and Welder Qualification.  Everything I knew about the subject I had just recently learned in a 1 week seminar.  I was nowhere near ready.
After about a week of banging my head, falling asleep reading and making zero progress, that Quality Mgr suggested I enlist the help of others, and that’s what I did.  I found that all throughout our company we had resident experts on some portion of the subject matter. 
Long story short, I mottled through with the help of just about every department in the company and came up with my first Weld Quality Program.  As difficult and frustrating as it was, it was an experience that changed me as a Welder and now, rookie QC inspector (6 months earlier I couldn’t spell QC).
So, none of that actually answers your question… or does it?  Who has, or gives, the power is not the real question here.  Who has the responsibility? is.  The responsibility lies with your Company, and as I found out early in my career, nothing less than the whole company is what it takes.
Good Luck,
PWC

Thursday, December 22, 2016

Don't forget to Ping that Weld


Paul, Got a question for you. I work in the mines, when we are welding something thick our boss tells us to "ping" our welds (excessive chipping /with air-chipper). I've never heard of that before. What’s your input?
Matt

Matt, Your Boss is offering some good advice.  He's actually asking you to peen your weld (I'm sure he says "ping" but this is what he means).
Peening a weld helps reduce what's called "residual stress". When you heat and cool metal it wants to move, but typically the weldment doesn't allow it to move. This builds residual stress in the part.  When residual stress exceeds "Yield Strength" you'll get distortion.  When residual stress exceeds "Tensile Strength" you'll get weldment failure.
Also, welding screws with the materials grain structure (at an atomic level). There are several ways to deal with this. You can Post Weld Heat Treat the weldment: raising it to what's called the transition temperature (Around 1600f), holding it there for some predetermined time and then allowing it to cool in some controlled manner. Or you could apply vibration (vibratory stress relief), vibrating the weldment during welding and shortly thereafter. Or you can peen, hitting the weldment with a peening hammer (or a scaler) to help reduce this stress.
So, what your Boss has you doing is stress relieving each pass to reduce distortion and /or the risk of cracking.  Listen to him.
Good question.
PWC

Wednesday, September 21, 2016

Become the "Qualification Guru of Choice"


Hello Paul,

Much like yourself, I am a CWI, CWE, teaching welding classes and following the guidelines of AWS D1.1, Structural Welding Code Steel.
I have purchased a number of the pre-qualified weld procedures from the AWS bookstore that fit the specific circumstances of the most common welding practices used in our area (6010 open root, 7018 fill/cover passes).  These weld procedures are referenced in the area on the WPS for welding procedure.
Students are given a written, step by step procedure with illustrations, dimensions and weld parameters for the fit-up and welding of their test plates. Each section must be followed by the students, and signed by the Instructors. The guided bend test is performed by a qualified AWS CWI, and the test results are documented by the same Welding Inspector.
My question is: does this weld test constitute a Welding Certification?
W.P.

 My answer is: It does, but will the contractors, manufacturers or company the Welder works for accept it?
AWS D1.1 tells us that Qualification (not “Certification”) is the responsibility of the “Contractor”.  They can “farm” the work of qualifying a welder out to an educational facility, but the responsibility for that Welder Qualification still falls on the contractor.  That’s the reason contractors give their own welding test regardless of any past qualifications the welding candidate may have.
Setting up a “Certification” program (meaning; backing up a Welders qualification with documentation) in a vocational school isn’t uncommon, but if that program is sold to Welders as a means of becoming “Certified”, you’ve done those Welders a disservice. They could go through your certification process not understanding that their new “Certification” is not valid anywhere.

Setting up that same “Certification” program and making your ”pitch” to area employers as the 3rd party qualification guru of choice would be far more honest and code user friendly.

I spent many years in the welding industry filling the role of Welding Engineer (The person responsible for the qualification of persons and processes), Welder qualification was a messy and time consuming part of my job.  When testing Welders “off the street” I would have a 10/1 pass rate (and then my 1 would fail the piss test).  I would always look to my area technical schools to help me with that, but I found either a welding program that didn’t give me confidence that ALL the requirements of qualification would be adhered to, or the program was nonexistent.
What do I mean by adhered to?:

•  Test plate fit-up met the WPS requirements
•  Test plate position was maintained from start to finish
•  The root pass was visually inspected (by someone who knows the acceptance criteria) and found acceptable
•  Fill passes were randomly monitored
•  The cover pass met the acceptance criteria without requiring repair to do so
•  The bend coupons were from the correct location and same test plate (I use steel stamps)
•  Removal of the backing and weld reinforcement did not fall below the plane of the base material
•  The samples were bent in the correct fixture
•  The person evaluating the bend samples understood the acceptance criteria
Seems simple enough, but at all of the locations I evaluated over my career, one or more (usually many more) of the requirements listed above were not met.
There’s a great need for the service you’re suggesting, just insure you are selling it to the right people.
Good Luck,
PWC

Tuesday, August 16, 2016

AWS-CWI's, Who needs 'em?


Good Morning,
I am very interested in a research article into industry perception of the overall value of the AWS CWI Certification. Many organizations have established training and certification programs internally that applies job scope specific training to inspectors while it seems that the AWS CWI training and exam is too general and wide ranging? Just looking for others opinions on this.
Thank you,
Victor K.


Hi Victor,
Although most codes accept the credentials of a Certified Welding Inspector (CWI) for visual inspection of welds, they DON'T REQUIRE that the Inspector be a CWI.  What they DO REQUIRE is that your Inspectors be qualified and that qualification be documented.  Those are two very important requirements; qualified & documented.  They are the requirements of welding codes that I will find not being adhered to when I'm conducting Fabricator/Manufacturer audits with in-house qualified Inspectors.

In your letter you state, "Many organizations have established training and certification programs internally that applies job scope specific training to inspectors..."  I've worked for many manufacturers and have developed those exact programs, but each program I developed insured that my Inspectors were "qualified" and that qualification was "documented". 

It is common in industry today to claim, "Our Welder is our first Inspector."  That's a great approach, but again, to make that claim, your Welders would be required to be qualified as Inspectors (don't confuse this with qualified as Welders) and their qualifications would need to be documented.

There is a document published by the American Welding Society (AWS) to help you develop that training and documentation; AWS-B5.1, "Specification for the Qualification of Welding Inspectors".  It is a terrific guide for developing a visual Welding Inspector program.  Programs developed by a knowledgeable Welding Inspector/Engineer to AWS-B5.1 would typically be excepted by your customers and/or governing agencies.  I have often found, once I've developed an "in-house" Inspector qualification, it was easier to evaluate employees and determine which inspectors may be ready to take the next step to certification.

It is typically your customers or governing agencies that put the requirement in contract documents that visual Welding Inspectors "shall" be AWS-CWI's (meaning certified to AWS-QC1-"Standard for AWS Certification of Welding Inspectors").  When listed in contract documents there's no "wiggle-room" for alternative qualification programs. 


From my own experience, walking onto a project overseen by an AWS-CWI gives me confidence that the Inspector has a good rounded background in all the different areas Inspectors need to understand.  Those areas include; Process, Code Requirements, Inspection Techniques and Metallurgy.  When I'm asked to be a 3rd party Inspector, and I find myself in a manufacturing environment where Inspectors are trained in-house, I tend to ask a series of questions that help me evaluate the qualifications of the other Inspectors.  I want to feel confident that they understand the requirements and the acceptance criteria for the weldments they inspect.  That is a bad time to find out they don’t, and I'll always ask to see their documentation.

I understand folks believing that Certification to AWS-QC1 (AWS-CWI) can, at times, be over-kill for some inspection requirements.  When an alternative program is developed you must insure that it is developed by an individual with a well-rounded understanding of welding requirements.  The kind of well-rounded understanding you'd typically find in a CWI.

Thanks for your question.
PWC

Friday, May 13, 2016

No means No

Paul,
Here’s a question. I’m certified through the Iron Workers Union and I been welding for almost 19 years. Everywhere I've ever worked they says no welding downhill and if you weld downhill you won't pass the structural test.  When running a vertical weld with 7018 rod is it correct to run a downhill pass before you start your vertical ups on Structural Steel? (This email was in response to welding per AWS D1.1:2015 Structural Code – Steel)
Joshua R.

Joshua,
I guess the short answer is "No".
To do so, you would need a weld procedure (WPS/PQR) that qualifies welding vertical up & down with E7018.  You might struggle to find an electrode manufacturer that would support vertical down with E7018.  We’re required to use electrodes within the manufacturer’s requirements.
You (the Welder) would also need to have taken a vertical up and a vertical down Welder Qualification test with E7018 (or another Low-Hydrogen electrode).  These would be F4 electrodes.  Welding vertically down is often done with F3 electrodes, but a structural test with an F3 (E6010) will not qualify you to weld with an F4 (E7018).
I always say that the pre-qualified section of AWS-D1.1 (Clause 3 – Prequalified Weld Procedure Requirements) is filled with good engineering advice.  My “day job” consists of Ultrasonic Testing (UT) of steel structures.  Often, when I find rejects, I also find that some requirement of Clause 3 was not met. When asked, “What should we do now?” my response is always the same, “Meet the Clause 3 requirements.”  That’s not often a popular response.
Clause 3, wouldn't allow welding vertically down with E7018, so again, my best answer is still, “No”.

Good Luck,
PWC