Busted a Pipe Test Yesterday

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Took two  2" 6G Monster carbon tests, one TIG all the way(with a damn foot pedal on 6G) and one Short Arc root, DualShield out. I busted the MIG. Passed the visual and busted out on the strap bends.I was having trouble with the short arc, I had a piece of 4 inch schedule 40 to set the machine heat. It would weld decent on the 4 inch, but when I tried to put the root in on the monster all it would do was spit and pop. I tried turning the heat up but that didn't work.They changed out the gun and that seemed to help some, but I already had 3/4 of the root in by that time. I must have ground out bird poop at least 5 times.I have quite a bit MIG experience, but it's been about 8 years since I welded with one, wonder what I did wrong? They didn't say where the straps busted. That DualShield don't work so good on 2 inch 6G.I've been offered $20 an hour to go to school to brush up and retest.
Reply:BTW, here's pic I found of a monster coupon, in case anyone wondered.
Reply:I want to get my cert. but i have to go to school 25 miles 1 way and cost $300. Its not bad but i guess its only the 1G test for that price and it 3 times a week for 6 weeks 150 miles aweek dang.
Reply:Yo Timmy, your a proven welder bro! Dust yourself off and do what you gatta do bud, you just got caught with your shorts down.  I hate being bi-polar it's awsomeMy Heroes Have Always Been Cowboys
Reply:30 years of pipe welding and now I need to go back to school.I'll take their $20 hour to go to school for a few days.I haven't busted a test since the early 90's.Last edited by TimmyTIG; 03-19-2013 at 07:51 PM.
Reply:Originally Posted by weldermikeYo Timmy, your a proven welder bro! Dust yourself off and do what you gatta do bud, you just got caught with your shorts down.
Reply:Just out of curiosity, was the root ran up hill or down hill?
Reply:short arc root-downhillDualshield fill and cap-uphill.
Reply:Originally Posted by TimmyTIGTIG all the way(with a damn foot pedal on 6G)
Reply:I thought about doing something like that, but this was a high freq rig and didn't have a cut off valve on it, the argon would have been running the whole time. Not to mention I probably woulda gotten flashed every time I put the tungsten anywhere near the pipe.Then when I got done they made a joke about me sitting on my bucket thru the whole test, hell I had to sit down so I could work the dern foot pedal on the bottom.
Reply:I'm sure he didn't use the high freq. Being as he had lots of experience with scratch start Tig rigs being hot all the time was not an issue for him. And he wasn't paying for the argon!Don’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:This is the first time I have heard of a foot pedal used for welding pipe in a 6G position GMAW and FCAW (especially the former) are always susceptible to lack of fusion.This is the reason that in EN standards although for welder qualification radiographic testing is sufficient, for GMAW extra bend testing is required.I always disliked the fact that manufacturers call me to qualify welders without giving the welders the chance to practice on the particular application and set the correct parameters.Good luck next time.
Reply:They use a pedal in my school. Is there something wrong with it? Or is it one of those things that you don't do in he field?
Reply:A foot pedal is only practical when you are able to sit down, something almost impossible when welding pipes in the field.Imagine having to lie down to weld the bottom of the pipe and having to use a foot pedal.Or trying to balance on one foot to use the foot pedal. It is just not practical nor necessary. A good welder when TIG welding does not need amperage control, just set to the prescribed value and adjust the welding speed when necessary.
Reply:Well, they gave me another shot at it today because of all the problems I was having with the short arc, put me on a different machine and welded much smoother. See what happens later today.One strap had a crack in it about a quarter inch right in the corner of the strap on the root side. So that bad short arc got me. The one today welded just fine.
Reply:Originally Posted by jamesyarbroughThey use a pedal in my school. Is there something wrong with it? Or is it one of those things that you don't do in he field?
Reply:pfaw, I busted that stupid MIG test again! 2 little cracks in the root side of a side bend. Maybe the welding Gods are trying to tell me something?It's a good thing my name's not TimmyMIG!Last edited by TimmyTIG; 03-21-2013 at 12:37 PM.
Reply:On the first machine you used.  Two issues that come to mind.  Drive roll - in other words wire slipping.  Had the issue where I would set the machine up - test it, everything fine, then move to weld and couldn't get a steady arc.  Then I noticed that where I was welding was closer and I had much tighter bends in the cable.  More drive pressure solved that.  Later the Miller guy suggested just cranking down on the pressure on the 350p - don't finesse it.Next on the Multimatic I had a bad connection on the machine itself.  Weld was cold.  Turning up the power didn't help.  Looked ugly and inconsistant.  On that machine I pulled back the rubbery cover on the Twelco and tighted it with a wrench (there is a rubber O-ring that was too thick).  Back to smooth.As for your 2nd test failure.  I'd love to hear the explaination and what to do to avoid it in the future.  Anyone?Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:Here's my explanation, take it how you will.That 2 inch heavy wall pipe is so small that you can't cut 4 straps without including a tie in or two. Tie ins on the root are notorious weak spots, especially with MIG.In my opinion, it's a stupid test. They should test on a 6 inch so you can cut your straps in between the tie ins. Then if they need to put you on something the 6 inch test doesn't cover, do a production upgrade, which all that involves is shooting an X ray. I have no doubt the root I put in yesterday would have passed X ray.On the first test, they called the maintenance man over to look at the machine. He tightened the drive rolls, tightened the ground connection on the machine, and when that didn't help, he changed out the gun completely. I have no idea what was wrong with that rig, but it didn't want to weld right.Last edited by TimmyTIG; 03-21-2013 at 06:52 PM.
Reply:Your coupons appear to be 1.5" schedule 160 pipe. Thats a standard heavy wall test thats usually done with stick. (6010 root, 7018 fill and cap).JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:That's just a picture I found on the internet, I didn't take it.I found out Wednesday I tested on 2" Super Coupon, which is actually a tad thicker than a monster coupon, I believe.Pretty common test these days, I guess it covers you to weld anything 1 inch and above, all thicknesses. I just don't like doing it with MIG.
Reply:I'd have to agree that the test might be stupid... Unless they are testing you to figure pre-heat, weld heat input & maybe filler on the test???What do you have - maybe 3 starts & tie-ins? Solid wire mig has a hell of a problem with hardness at the toes of the weld which can fail when you deform the coupon (might be why the ASME guys are so anal about testing there for quallys - especially for "lethal designations". You can do it perfect then bust out (E70s-6 wire is no "prize" for hard toes either, s-3 is much better if you can use it)...To do it without pretty serious pre-heat I'm thinking you'd have to grind back half again as much as you would with 6010 to have a chance on that 2"... Three times??? There's no speed gain I can see.Maybe I don't get it. Matt
Reply:I put two bridge tacks on it and tried to weld in between the bridge tacks to minimize the tie ins, but I had a couple of spots I had to grind out and re-do, so there went that idea. That test is just take your best shot and hope you get lucky, in my opinion. If you could bridge tack it, then put the whole root in perfect without having to fix a spot you might make it, if they don't cut a strap on your two tie ins.I don't think I want to mess with a test like that again, it's too much work for such a small shot at success.
Reply:This for JV school?
Reply:no, but I'd rather not say any more on here about it, it's still in the works