Welder Retest

By Lawrence (*****)

Date 10-20-2007 15:41

Shipfitter....

I don't have access to any Shipbuilding of DOD Mil-Spec texts.

You did not mention which code your welders must comply to, but, since we are in the D.1 section, here is at least something

Here is what D1.1 2004 says about retests

4.32 Retest

4.32.1 Immediate Retest
"An immediate retest may be made consisting of two
welds of each type and position that the welder or
welding operator failed. All retest specimines shall
meet all the specified requirements."

4.32.2 Retest After Further Training or Practice
"A retest may be made, provided there is evidence that the
welder or welding operator had further training or practice.
A complete retest of the types and positons failed shall be made.

Also see 4.32.1.3

4.32.1.4 Exception-Failure of a Requalification Retest.
No immediate retest shall be allowed after failure of a
requalification retest. A retest shall be allowed only after
further training and practice per 4.32.1.2

By 803056

Date 10-20-2007 17:01

Two acceptable test coupons if no further training is invoked.

Ah, but what constitutes "training"?

Some contend that a simple word of wisdom such as, "your amperage it too low." constitutes training if is is said with a loud voice.

Others contend that eight hours of burning wire is necessary. In which case, burning wire with no further instruction or oversight would be sufficient to meet the requirements of the code.

Both senarios in my opinion miss the intent. I have no hard and fast rules other than the welder has to submit two consecutive samples that meet the applicable visual acceptance criteria before being retested. If the candidate failed because he/she was nervous, a long drawn out training session is not usually required. On the other hand, someone that clearly lacks the skills necessary to make a sound weld may need a week or more of training to improve their skill to the minimum level needed to pass the test.

Whereas the codes do not stipulate any "retraining" requirements or conditions, it is at the sole discression of the employer/inspector as to what constitutes "training".

As I have stated in previous posts, I like to see the company's policies in writing so there is no question of what is required before testing is started. I like to see a welder qualification program that delinates what the welder can and can not do during the test (can the plate be removed from the test position for interpass cleaning?), what tools can be used (can power tools be used for interpass cleaning), under what conditions can the test be terminated (the welder puts the wrong end of the electrode into the holder?), etc. I like to see the acceptance criteria that will be applied. And of course, I want to see a written WPS. It may be a prequalified WPS or one that is based on a PQR depending on the code that is applicable. I also like to see some objective evidence the welder has read and been told what to do and how to do it. I have the welder sign the bottom of his copy of the documents just described and they are kept in his/her test area and turned in along with the completed test sample.

Best regards - Al

By shipfitter88 (*)

Date 10-20-2007 23:16

Al,

I am a new CWI and also an instructor at a local high school which is a AWS accredited test facility. I really enjoyed your response. I am sure I will use this forum alot to gain the wisom from the more senior CWIs.

Chris

By 803056

Date 10-21-2007 14:50

Welcome to the forum.

I happy to see you are already a member a "club" composed of distinctive gentlemen that are also active on the forum. I'm referring to the gentlemen that are passing on their knowledge and skills relating to welding to the next generation of welders. Specifically, I am referring to Lawrence, aevald, and other that are welding instructors and who freely share their wealth of knowledge with their students and everyone that asks for their help.

I gain much more than I contribute in the way of ideas and information.

My biggest concern is that you, like me, will find yourself spending all too much time reading the posts on the forum. The advertisers on ABC, CBS, and NBC are complaining that their viewership is declining. That's because so many of us find the forum much more stimulating than television!

Again, welcome to the forum. i hope you find it as much fun as the rest of us do.

Best regards - Al

By aevald

Date 10-21-2007 21:36

Hello Al, Allan here, I got the biggest chuckle out of your mention of the networks complaining of losing viewers to the forum. I believe it is true though, I know that I enjoy the heck out of coming on here and being apprised of the many different facets of our trade and learning immensely from everyone on any number of different topics. Many times I would much rather read the posts(questions and responses), than sit down and watch something on TV that has very little true meaning. Best regards, Allan

By pipewelder_1999 (****)

Date 10-21-2007 22:21

Sometimes ALL THAT IS NEEDED IS "your amperage was too low".

If bad welds could be "trained out" of a welder then we would all just need more training before gong on a job. If doing MORE welds makes us BETTER then after so many shots should we just walk on the job with our starched carhartts pressed with seams and our SS tubing custom built belt buckle ?

As an inspector, use your judgement as to which option to use. If I see a guy weld up a coupon and it shoots bad I may or may not let him retest with only a few words. If I make him do two coupons, he will some how have to take his "golden arm pill" to make it all better.. What if one of those is good and the other is bad ???

I use my judgemend but almost ALWAYS go with training. I think the two coupon deal is stupid. Just my opinion though. Its a good thing for people that may not have someone around with the ability to do a little training with the welder or to make a judgement call on weather a guy can weld or not.

By 803056

Date 10-21-2007 23:02

Maybe I'm simply misinterpreting what you wrote, (maybe it's all that yelling in your post) but most welding standards are in agreement that if a welder fails a test, two coupons have to be tested if the test is given immediately. What they are trying to prevent is that given enough tests, a monkey will eventually pass the test by simple chance.

Likewise, I make the welder that is in "training" submit two consecutive test pieces that have to pass the required visual criteria before being considered for a requalification test. Once again, the purpose is to filter out the "fluke" and ensure the welder has acquired the minimum necessary skills to pass the test on the next attempt.

Most of us that have work in the field as inspectors have encountered the contractor that give the welder several sets of test coupons tells them to hand in the "best ones" to be tested. Most of us will agree that isn't the intent of the "codes".

I too tend to lean heavily on "training" if it is clear the welder needs additional skills training, but the choice of an immediate retest or additional training is really up to the contractor that is footing the bill for the testing, not the third party inspector.

Oh yes, by the way, both coupons do have to pass before the welder is "qualified" by an immediate retest. If one fails, then the test is done and the welder fails. And no, I will not test a coupon before the second one is completely welded. They are a pair and as such they are tested together, not separately. Eight guided bends if the test is taken in the 6G position, they all pass or it's back to the booth. Immediate retests can become very expensive very quickly. Most contractors don't go for a second round of testing until they are fairly certain the welder can pass.

Best regards - Al

By pipewelder_1999 (****)

Date 10-22-2007 03:37

Not really yelling. But I do see your point about the fluke. I just see it from the other side. Weld enough times, even a great welder will bust a test. Maybe even two in a row. Does that make him a bad welder. Maybe he is or maybe he isn't. However discussing the possible causes of the defect in my opinion goes MUCH farther than having that same welder weld two coupons. Welding some coupons with visual inspection is a good idea. Just not always going for the two coupons back to back.

A fitter can show up to a job with a bucket of tools, an inspector can show up with nothing more than a CWI card, and NDT inspector just has to keep working but does not have to recertify in many cases. However all of these above trades encounter "variables" in what they do that make them more or less proficient than required for the job.

The codes allow training to be performed or two coupons in most cases. These tests cost money and time. In some cases the welder is not paid but the guy cutting the straps and bending them is. An inspector or welding foreman can spend a short period of time discussing the cause of the defects, improve the welders skill, let him take one test and see if it sunk in.

As a third party inspector we should have no say so on what method they use unless project specifications state otherwise. As an inspector for a contractor, I use my judgement based on what is allowed by the project specifications/codes and my experience as a welder.

As you said below, immediate retests can be very expensive. Immediate retests do very little to change the skill of the welder. If its obvious a person can weld (not always shown by welder qualifcation test bends or radiographs) then I discuss with them what may have caused the defect, call it training, and do one test. Sometimes it takes 5 minutes, sometimes longer and sometimes shorter.

I think the whole welder certification situation costs industry a great deal of money. I have welded 12-15 2" schedule 80 coupons in one year just to GET A JOB. Sometimes with the same contractor at a plant owned by the same end user. I have tested with a company at a jobsite, worked the outage, went to another outage for the same contractor at another site owned by the same end user. I tested welders this week that just came off jobs to weld on an air heater. Not allowed to retest. Wasted trip. Some of these guys just didn't have the skill. Others had elongated indications in radiographs greater than .166" long in a 1/2" plate but were slick welders. One position out of 3, I had to send them down the road because they busted RT. People I looked out were sent back to retest or were retested at the jobsite because of political issues.

Is welding the only job in which one gets less proficient as they get more experience ? I think a centralized and standardized testing and maintenance of certification program should be utilized more. The "commonarc" system by the boilermakers seems to have some issues based on the current job I am on in which guys are telling me they left jobs within the last month or two with participating contractors yet the system does not show them as current.

Im done now. No yelling :) .

Have a good one

Gerald

By 803056

Date 10-22-2007 12:02

I agree that welder qualification an expensive proposition, but it is less costly than making on the site repairs.

Several years ago there was an article in the Welding Journal about the cost of a weld based on the total cost of engineering, design, implementation, and inspection. Granted this was for a nuc., but the total cost was much higher than one would think. In comparison, the cost of qualifying a welder is "peanuts".

I used to think as you do when I was burning rod for a living, and yes, at times it seemed like a wasted effort to retest several times a year. However, in hind sight and with my experience as an inspector, the time and effort expended to test a welder on site is a worthwhile investment. I have listed several reasons why I believe it is worthwhile:

a) it gives the welder an opportunity to become familiar with the project requirements and the WPSs that will be used on the project.
b) most companies do not use the same welding procedures or techniques, thus the welder may have different requirements to meet.
c) each welding code has its own acceptance criteria which the welder may or may not be familiar with. I test the welder using the acceptance criteria that will be imposed on that project, i.e., B31.3 normal service is different from the requirements for high pressure or B31.1, or Section VIII.
d) unfortunately the welder's skills do change over time. Usually it is related to age and declining visual acuity with people over 40.
e) you never know if the requirements of the code were met on the "last test" because some inspectors take exceptions to the codes.
f) while some projects do have stringent inspections, i.e., either UT or RT, many project have little inspection or nothing more stringent than visual examinations.

So, after two and a half decades of welding inspection experience and more than twenty years of experience under the welding hood burning wire, I feel fairly confident I am speaking with a good amount of knowledge about the subject of welder qualification.

By the way, the purpose of qualifying the welder is to demonstrate the welder has the minimum level of skill required to deposit a sound weld. If he or she can't make a good weld in the booth, do you really expect to see an improvement in production?

Gotta go, I have a few welders and an inspector to qualify this morning.

Best regards - Al

By pipewelder_1999 (****)

Date 10-22-2007 23:30

You have some good points that I could agree with in many cases. I may have been on a the wrong projects over the years. Often times the welder is never given a WPS to follow nor is he informed about the acceptance criteria and project specifications. Often this is left up to the inspector/Qc person giving the test.

In cases in which the welder is expected to perform in situations that exceed the code requirements by virtue of project requirements indicating additional testing is required, I agree.

Many of the vision changes are correctable. As with inspectors, Eye exams should be required. Near vision acuity is easily checked.

I would think the level of inspection would be the item controlling the leve of assurance required for weld integrity.

Anyway, very good points you have brought forward and I appreciate the conversation.

By 803056

Date 10-23-2007 03:04

Thanks pipewelder_1999.

I had an interesting situation today.

I tested four welders, each with 20 plus years of welding experience in the shop.

I helped set this shop up back in the early 90's. We qualified the welding procedures, wrote WPSs, and developed a QC manual that included some thirty pages on the control of welding processes.

This morning was the first time any of the welders had ever seen the manual or a written WPS. No one realized that because they had originally pursued work for the Navy the welders were required to pass a written examination, a visual acuity test, and the hands-on demonstration of skill. I guess it is time to up date the manual.

The welders were given a fillet test in the horizontal position using gas shielded FCAW. Straight forward test, no tricks. As a group, we reviewed the "rules of testing", acceptance criteria, and the WPS.

Each of the welders were given a set of plates and we checked the machine settings against the WPS after the welders were satisfied they were comfortable with the machines' operations. No instruction on welding technique was offered other than what was in the WPS.

Each of the four welders used a forehand technique, that is they "pushed" the torch and produced beautiful single pass 5/16 inch fillet welds, but each one failed due to incomplete fusion in the root. They were astounded that they didn't pass the test, "Its only a fillet test!"

I told them that I have never had a welder pass the fillet break test using the "push" technique. This is true, after twenty plus years, I have never had a welder pass the fillet break test using that technique. That's why only backhand is listed in their WPS. However it is common practice to use a forehand technique in many shops. That is, until I test them.

To make a short story of a very long day, I taught them to use the backhand technique and after several hours of practice they all passed. They agreed to a man that the backhand technique beat the forehand method. One welder said, "This is like learning to weld all over again."

Then they asked the question, "Why were we taught to use the forehand technique in school?" I had no good answer to that one.

Best regards - Al

By pipewelder_1999 (****)

Date 10-23-2007 10:01

Cool! The forehand/backhand for FCAW has been a problem where I have tested in the past. Here is a forehand welded FCAW joint filled with thick layers. This was an actual production joint in which I had warned some about. I was a third party inspector so it was not taken seriously.

By Lawrence (*****)

Date 10-23-2007 11:45

Al,

Thank you for the story.

This one is getting pasted up on the board in the weld lab.

By 803056

Date 10-23-2007 13:21

Hey Pipefitter, I love that photograph. I have one that is similar in my ASME presentation that addresses the proper geometry (and depth) for back gouges, but I would put money on the line that they also were using the forehand technique with their GMAW (spray) when the weld joint was produced.

To add to the story, after breaking the first four test samples and showing them the incomplete fusion and slag in the root of the end pieces, I told the welders they could take the test using either the forehand or backhand method. I then ran a single pass 5/16 inch fillet using the backhand method with the trust tried and true triangular weave. The root penetration was between 1/16 and 1/8 inch. It was then and there that they agreed the backhand method was what they wanted to learn.

It was more difficult to break them of their habit of making little circles and other gyrations than it would have been to teach someone that had never welded with FCAW. In the end they all passed with smiles and slaps on each other's backs. The shop's best welder had the most difficult time learning the new technique, but once he nailed it, it was all smiles.

I told him, the twenty sixth time was the charm. Everyone started laughing and he said, "Al, you have a way about you that takes the pressure off. By now, after the day I've had, I would be ready to slug someone! You make it look so easy."

I told him after using the new method over the next two days, it will be just as easy for him and he would wonder why he ever tried it the old way.

Gotta go. I have a job to go to (after having a quick breakfast with the grandkids)!

Lawrence, see you in Chicago!

Best regards - Al

By bozaktwo1 (***)

Date 10-24-2007 16:54

I have been asking that question for over 20 years, myself. There are two basic rules that all Navy welders live by: never go downhill, and always push the torch. My instructor at the navy's high pressure weld school couldn't tell me; however we were doing all SMAW and GTAW there, too. Some years later, as I was hanging off the side of an aluminum superstructure on some frigate or another, repairing a 30 foot long crack, I got to thinking about it again. My qualification for that had been run pushing the torch; we were all having a lot of difficulty making those welds, mostly due to the 120 F heat, but I went ahead and tried it anyway and was pleasantly surprised at how much more smoothly the filler laid down. My Chief found out and went ballistic, so I had to grind it out and reweld it "the right way."

By ZCat

Date 10-24-2007 17:28

I always had trouble with undercut on backhand Dualshield fillets. Not so with forehand.

By 803056

Date 10-24-2007 19:12

Techinque my good man.

Al

By ZCat

Date 10-24-2007 19:56

I guess,... I tried and tried and I never could figure it out.

By 803056

Date 10-24-2007 20:58 Edited 10-26-2007 21:57

The forehand technique looks pretty, but it will bite you if there is anything other than visual examination, i.e., RT or UT.

Try a couple of fillet breaks. You'll see slag and incomplete fusion in the root if you try to make a single pass 5/16 inch fillet. The only method I've seen that works consistently is the backhand method using the triangular "weave". It is like making a vertical fillet with vertical progression. In the horizontal position, I start on the horizontal (non-butting) member about 1/8 inch from the vertical (butting) member. Then proceed straight up to the vertical member about 1/4 inch from the horizontal, then move toward the front of the puddle and reach just beyond the leading edge about an 3/16th to 1/4 inch. Then move back and out to the side about 1/4 inch to develop the horizontal leg of the weld, back up to the top, again about 1/4 inch from the horizontal plate and then beyond the leading edge of the puddle by about 3/16th to 1/4 inch, and keep repeating. All your movements should be in a straight line with no swirls or loops. Just like you were drawing a triangle that is laying in the corner of the two intersecting plates.

The attached sketch might be tough to follow, but try to follow the numbers to get the right sequence of electrode movements. All moves are in straight fluid moves with no hesitations at the corners or in the root. Point the torch down at about 35 degrees and use about a 15 degree lead (pull) angle.

Good luck.

Best regards - Al

Attachment: WeldSeq-TriangWeave24-Oct-07.dwg (23k)

Attachment: WeldSeq-TriangWeave24-Oct-07.wmf (18k)

By shipfitter88 (*)

Date 10-20-2007 23:07

Lawrence,

Sorry I forgot to add which code I was testing to. Yes it was D1.1 and I greatly appreciate your assistance.

Chris