The Facts about Weld Porosity   As printed in The Welder Magazine

Do you give the Welder "test taking tips"? -or- Do you shut up and let the Welder pass or fail on their own?

So, a company is paying you to help them comply with AWS/D1.1 You've written the WPS's and now it's time to qualify the Welders. Do you give the Welder "test taking tips"? -or- Do you shut up and let the Welder pass or fail on their own? -and- Once they fail, do you give the Welder test taking tips before the re-test?

Keep in mind the premise... a 3rd party inspector helping a company that requested it, comply with AWS-D1.1

Often, in fact usually, when I'm in this situation, it's a small company looking to bid on a job that is requiring them to do something they've never had to do before; show proof of compliance to the structural welding code. These companies are too small to have a Welding Engineer on staff and wouldn't have a Certified Inspector. Generally, what I find, they have a Welder they've hired, or has been working for them for some time. His/Her qualification documents (if any) are from a previous employer. The company is counting on their Welder to know all that is needed to know about welding the product.

I'll also find that the company needing to comply with AWS-D1.1 doesn't own a copy of the code (or the copy they have is 2-3 revisions old).  So now they've called me to see if I can help them out. I'll typically tour the shop, view the product, watch how the sausage is made... then I'll come up with a list of recommendations;

• These are the codes you need to comply with (typically D1.1 and D1.3, but often others as well).
• These are the Pre-Qualified WPS's needed.
• These are the Qualified WPS's needed.
• These are the Welder Qualifications required.

Total cost can easily fall around $3k-$10k, so we break it into small chunks. 1st the Pre-Qualified WPS's, then some Welder Quals... and that brings us back to my original question, "Do you give the Welder test taking tips?"

I'm going to provide the Welders a detailed WPS. I'll provide detailed test instructions. I'll let them know the acceptance criteria (visually acceptable root pass, cover reinforcement/crown not greater than 1/8"...). I'll answer every question they'll ask. Beyond that, I have to leave them on their own. Under this scenario I have to know / they have to know, "Do the skills and techniques that they have/use today get them the required result?" Most of the time, they do not. Failing the Welder Qualification test shows the Welder and the company that the process they currently have in place doesn't work. Something needs to change.

Had I offered helpful tips on the initial Welder Qualification, and the test fail, the only response would be, "The Inspector told me to ____ and that's why I failed." On the retest I will always ask, "Can I give you some tips?", but never on their initial test.

In a School or Training situation, that is a different scenario, but this isn't training. This is determining if the process you currently have in place yields the result you need and if not, what needs to change.

Thanks for reading and following.
PWC

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

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

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 3^rd 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

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

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