Confused on procedure.. 3G cert test.

I will probably be testing for 3G and 4G Mig certs in the near future.

I've been welding for many years, but the majority of the work in our shop is 16ga. tube, so the idea of 3/8" plate is a little outside of my comfort zone.

I was looking at the following website, which seems quite helpful, but I cannot figure out what the guy is talking about when he gets to the section about preparing the coupons for testing...

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The root ought to be fused to the backing bar, right? Yet he talks about splitting it off with a chisel? Can anyone clear up the procedure?

Also, does anyone have experience with the Hobart program in Troy, Ohio? This is the closest AWS facility to us.

Thank you for your help.

Stuart

Reply to
Stuart Wheaton
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Did you miss the part where he ground the center of the backer bar off "without penetrating the test coupon" ?

Reply to
Snag

I didn't miss it, but I'm not sure how one grinds out the middle of a bar without nicking the stuff below it. Is this a test of grinding skill or welding skill? What does the stuff about marking the root penetration refer to? I weld a lot, but the grinding needs in my world are taking down welds so that the covering can lie flat when it is screwed on. You don't put a backer bar in 1x1 16 ga tube...

Part of the trouble is that the material we will be working with post cert will still be mostly 1x1 box tube up to 11 ga. with some 1.5" schedule 40 pipe and occasional plate gussets, the pipe is not for pressure, just for structure or appearance. Once I get the cert, I will never need to weld 2 pieces of 3/8" plate again.

Stuart

Reply to
Stuart Wheaton

I see what you're sayin' . I never had much training , and what I got was like 45 years ago in high school/from my dad . Most of my welds look "OK" , but I seriously doubt they'd pass and kind of cert procedure . The one thing I learned rather quickly is that a MIG welder will make a weld that looks great but didn't penetrate . I make sure that I see fusion on both edges ... even if it leaves a slight undercut . But then I'm not welding man-rated stuff.

Reply to
Snag

As a Certified Weld Inspector I can clarify your situation.

The most common MIG tests are

1 inch plate v-groove with a backing bar

3/8 inch v-groove with a backing bar

and thick-to-thin i.e. 16 ga T-welded to a piece of 3/8 inch plate

There are no standard square tube or rectangular tube tests for MIG. However any CWI can create one for a company. The most common test given is the 3/8 inch plate test with a backing bar. This test qualifies you for up to 3/4 inch steel. By doing the 3G (vertical up) and the 4G (overhead) you are qualified for all positions (1,2,3 and 4) with Groove or Fillet welds.

When the coupon is cut from the test plate the small square of backing bar must be removed. It can be sawed off, ground off or ground and chiseled as long as no harm is done to the remainder of the test coupon. The weld metal above the plate surface on the face of the weld is also removed. The edges are smoothed and slightly rounded so you are left with two 1 inch wide, 3/8 inch thick and 6 inch long test coupon. One is bent towards the face of the weld and one is bent towards the root of the weld As long as no discontinuity 1/8" or larger is visible after bending, on both coupons, the test weld passes.

Reply to
Ernie Leimkuhler

Hard wire MIG, without pulse arc, vertical and overhead? aahhh huh .... this I gotta see ..... ;>)}

"Ernie Leimkuhler" wrote in message news:100220120115262666% snipped-for-privacy@stagesmith.com...

Reply to
Phil Kangas

The trick is to run the machine very low with a small wire.

16 - 18 volts 160 - 200 inches per minute wire 0.035 inch ER70S-6 wire

In production welding the machine is usually set much hotter, but for testing we go low and slow.

Reply to
Ernie Leimkuhler

Shouldn't the weldor qual test use the same parameters as used in production? This test is worthless.....

"Ernie Leimkuhler" wrote in message news:120220121458215426% snipped-for-privacy@stagesmith.com...

Reply to
Phil Kangas

I would not say worthless. If you can turn a 180 degree bend in a finished weld, and have it stay attached to the base metal, you have obviously shown a degree of skill as a welder. If the welding procedure is critical to the final product, the welding procedure for the actual weldment ought to be qualified, which includes joint design, and machine settings.

The test is a thorough test of welding skill under difficult imposed conditions. to that degree, it has value in sorting out the skilled welder from the guy who might be better off doing non-critical welds.

Reply to
Stuart Wheaton

Be sure to report back here if anyone passed that

4G test, eih?

"Stuart Wheat>> Shouldn't the weldor qual test use the same

Reply to
Phil Kangas

Now that I think of it, both you and ernie should be the first ones to do it to prove to the guy you pick that it can be done!

"Phil Kangas" <

Reply to
Phil Kangas

What is the purpose of the backing bar? On all the tests I have done, they were open root, 6010, then 7018 cover. What does the backing bar do? It seems like that would make it a whole lot easier, as getting a good root pass on an open root is not an easy thing.

I have had 2g, 3g, 4g, 6g, 6gTIG, and 2G 6010++ root, .072" FCAW filler w/argon 36" diameter 1.5" wall pipe (oilfield caisson) certifications. Other yard tests for specific duration jobs that were uncertified, just full x rayed. No need to certify, you passed or failed. And more than two cutouts, and you had your own personal helicopter flight to land.

Don't mean a lot, since I haven't done them in the required 6 months previous to today, but they sure sound good, no?

Certs are nice. But it's better, IMHO, to have a guy that can weld consistently and predictably, and who can put up with the on the job conditions.

Backing plate seems like making it a whole lot easier to pass.

Steve

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Reply to
Steve B

I have run cert. type welds hundreds of times over 16 years of teaching for my students. I can run cert welds in my sleep in MIG, TIG Dual Shield, Inner Shield, and Stick, on pipe, sheet, plate and beams, on steel, stainless, aluminum, bronze, copper and titanium.

It doesn't mean I "want" to, just that I can. I simply had a lot of practice while teaching. And my brain is wired to absorb technical procedures. Terrible with names and faces, but great with technical info.

The Weld test I described is a "Pre-Qualified" test, meaning it is a standard test given to a lot of people. Any company can have a CWI create a new procedure for their specific parameters. Genie Industries has a whole 3-ring binder of custom WPS's (Weld Procedure Specifications) Boeing has the same thing.

A lot of high production facilities have WPS's written for the way they do things. The downside to that is the certs are company specific and do not transfer to another job.

Reply to
Ernie Leimkuhler

Yes, the _test plate_ is a standard one. The problem is running short arc mig overhead in this groove. The intent to do so immediately raises a red flag as this is not a pre-qualified procedure. Short arc does have its place but must be used with caution as rework can be extensive and expensive. I don't think such a test will pass bend tests if it is welded at all! ;>)} There is a reason that pulse arc has been developed for this application. To use this test as an evaluation of a weldors skill is questionable IMO. There are better ways to do it.

"Ernie Leimkuhler" wrote in message news:190220121517144650% snipped-for-privacy@stagesmith.com...

Reply to
Phil Kangas

Funny. Others have passed this test. Is it a conspiracy?

Or merely a lack of skill?

We may never know.

Steve

Reply to
Steve B

Did you pass a 4G short arc bend test Steve B? Did tinlizzie pass it? Anybody reading this?

Reply to
Phil Kangas

I have passed so many tests that I don't recall them all. I don't have to. I'm retired now. I probably passed that one. What's your point?

Steve

Reply to
Steve B

My point is that it is impossible to pass a 4G short arc bend test on 3/8 plate no matter how famous the ego of the weldor. The challenge is on.... ;>)}

Reply to
Phil Kangas

"Phil Kangas" wrote

There is no challenge, Phil. What you say is is.

Steve

PS: Welding tests are passed or failed on a science basis, not ego.

Reply to
Steve B

Backing bars are for "structural" welds. Pipe is usually run "open root". The only place I know of that runs open root plate welds is Canada.

Standard AWS D1.1 structural weld procedures state you weld a single sided V-groove weld into a backing bar, then carbon-arc gouge the backing bar off, scarf out the root and weld from the back side. For testing we just skip the last part so we can examine the root pass.

A bad root pass fails 90% of weld tests.

Reply to
Ernie Leimkuhler

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