Slag inside of bead okay?

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Working on a ute tray and am doing horizontal fillet welds. Since I don't get a good bead every time and usually takes 2-3 attempts each bead, I have decided to stop grinding it all the way back and trying again, rather I just chip and clean the slag as much as possible, then run another bead over the top which usually does the job.My question is; Since running a bead over the top of the initial bead usually traps un-knocked-out slag, How much is this a concern for the quality of my job. Is it worth grinding back completely and retrying till I get an adequate bead each time?
Reply:Rule #1:  never practice on the actual part.From your description, you need to practice more. That's a bad weld.Run a bead on a practice piece, take a pic, list rod size, type, and amperage and post the picture.It may just be something easy, like your amps are too low for the rod size, or your arc is loo long.Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:What electrode are you using? 6013-7014 is one of the worst for trapping slag. 6011 will tolerate slag better than most other electrodes. Like Dave said, practice on something other than the actual piece.
Reply:Originally Posted by Jack NielsenWorking on a ute tray and am doing horizontal fillet welds. Since I don't get a good bead every time and usually takes 2-3 attempts each bead, I have decided to stop grinding it all the way back and trying again, rather I just chip and clean the slag as much as possible, then run another bead over the top which usually does the job.My question is; Since running a bead over the top of the initial bead usually traps un-knocked-out slag, How much is this a concern for the quality of my job. Is it worth grinding back completely and retrying till I get an adequate bead each time?
Reply:You need to get your slag removed before welding another pass over top.  Problem is, if you have trapped slag in the toes of your weld, you have a good chance of burying more slag in the next pass even if you can get all the slag removed from the first pass. This is called a slag trap. It's created by the skinny crack you created from not having the toe of your weld washed into the base metal.If your welding on the farm, this isn't an issue. However, if your welding to code and have to pass a UT inspection or X-ray, your can't do this. You will need to grind out the slag trap or open it up a bit so slag doesn't roll under your bead into the crack on your next pass.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:Sometimes it's not easy to get all the slag with the slag hammer.  Have an extra 4 1/2" sidegrinder just for this job, equipped with either a flat or a cupped wire wheel, depending on which style will best get into the particular joint you're working with.  The knotted type of wire wheel seems to work best and last longest.  We're talking about wire-wheeling steel only.  A couple of passes with the wire wheel should get into the crannies and dig out nearly all the slag, unless you are really doing a poor job of making your joint fit-ups and of running your beads.From your post I'm wondering if you are self-taught, or uncle-taught, or maybe had a pal "show you how" for a few hours, or got a couple of weeks exposure for 35 minutes a day in a high school shop class.  None of those is likely to make you a welder.  Get into a day or night class at the local tech school or community college, and get some professional, concentrated instruction.  Among other things, you'll learn that running GOOD beads in a variety of situations is not so easy as you thought, and later you'll learn that running good beads is only maybe fifteen percent of what a GOOD welder has to know. Yet you will also find that the more you learn about it, the more fun it becomes. Disregard if none of that applies to you.Last edited by old jupiter; 04-27-2016 at 11:20 AM.
Reply:Sure it will be fine. Its like filling you forms with beer cans before pouring concrete to take up space.www.georgesplasmacuttershop.comPlasma Cutter and Welder Sales and Repairs--Ebay storeTec.Mo. Dealer Consumables for the PT and IPT torch's
Reply:You have not provided enough information.It depends on the situation but I don't think the welds need to be spit shined for the next bead. If you have porosity though and your weld calls for it I think you have to dig it out because you can't really know what is under there. Maybe it might come out on the next pass or maybe you did not get the job.
Reply:Well, from what the AWS folks who figure out the test allowances tell us, some porosity and even undercut are generally not nearly as bad for weldment integrity as entrapped slag.  Mike, I would agree that especially with a good digging rod like E6010/6011 you probably don't have to get every last speck. But in the school I was at forty years ago, they had each of us on the track-torch, cutting many very thin slices in our finished test-plates specifically to find entrapped slag.  You made the first cut parallel to the bead and at one edge of it, and then you make slice after thin surface-slice down the bead.  It was sort of humiliating the first time, because you thought maybe you were starting to make decent 7018 welds, but unlike 6010/6011, you learned that 7018 is not very forgiving. As you carefully watched each surface-slice you would see the ugly evidence as entrapped slag would deflect the flame and mess up the cut.  Not fun to see, but it made you quickly fix whatever you were doing wrong, and after a while you could watch one neat uninterrupted slice after another through your unadulterated test-plates.
Reply:Slag entrapment is a failed weld no matter what process is used.REAL TRUCKS DON'T HAVE SPARK PLUGS
Reply:Originally Posted by old jupiterWell, from what the AWS folks who figure out the test allowances tell us, some porosity and even undercut are generally not nearly as bad for weldment integrity as entrapped slag.
Reply:Originally Posted by Jack NielsenWorking on a ute tray and am doing horizontal fillet welds. Since I don't get a good bead every time and usually takes 2-3 attempts each bead, I have decided to stop grinding it all the way back and trying again, rather I just chip and clean the slag as much as possible, then run another bead over the top which usually does the job.My question is; Since running a bead over the top of the initial bead usually traps un-knocked-out slag, How much is this a concern for the quality of my job. Is it worth grinding back completely and retrying till I get an adequate bead each time?
Reply:Originally Posted by mechanic416Sure it will be fine. Its like filling you forms with beer cans before pouring concrete to take up space.
Reply:Why are so many posters assuming he used 6013? Regardless of what rod or process he used the question was how much of a concern are slag inclusions to the quality of the job. The answer to that question is that you can't put slag inclusions and quality in the same sentence!
Reply:WNY_TomB is, more or less, THE forum advocate for 6013. Most people just ignore him, just like the ones that say that 6010 is a garbage rod or self shielded flux core is a useless process.
Reply:Slag left in a weld is never an acceptable procedure. Leave slag in your weld on a weld test that is cut into coupons and bent and you will fail your weld test. The buried slag opens up as a crack when your coupon is bent in the press.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:Slag inclusions are never desirable, but up to a certain point they are acceptable.Also, you should study up on the allowances for inclusions in a bend test. For AWS D1.1, for example, you are allowed slag inclusions in a bend test so long as no one crack exceeds 1/8", and (if memory serves correctly) all the cracks added together do not exceed 3/8".  Originally Posted by snoeproeSlag left in a weld is never an acceptable procedure. Leave slag in your weld on a weld test that is cut into coupons and bent and you will fail your weld test. The buried slag opens up as a crack when your coupon is bent in the press.
Reply:One can never assume that a cover pass will "melt" out the slag.  Shouldn't even be considered a sane procedure.Grind it back, and do it right.  After a few cycles of grind-outs, you generally get fed up, and do it right.If we're talking slag, we're probably talking a drag rod??  If it IS a drag rod......shove it in there tight, and keep movement to a minimum, just let it flow.  Slag entrapment generally comes from a bad technique, a consequence of a bad puddle.  Watch the puddle, it tells all.  It tells you if the amps are correct, the travel speed is correct, and whether you're not getting tight enough.When welding with a rod that produces large amounts of slag......never go back into the puddle.  You'll wind up going back into the slag.  No whipping."Any day above ground is a good day"http://www.farmersamm.com/
Reply:Originally Posted by farmersammOne can never assume that a cover pass will "melt" out the slag.  Shouldn't even be considered a sane procedure.Grind it back, and do it right.  After a few cycles of grind-outs, you generally get fed up, and do it right.
Reply:Originally Posted by Hillbilly WelderSlag inclusions are never desirable, but up to a certain point they are acceptable.Also, you should study up on the allowances for inclusions in a bend test. For AWS D1.1, for example, you are allowed slag inclusions in a bend test so long as no one crack exceeds 1/8", and (if memory serves correctly) all the cracks added together do not exceed 3/8".
Reply:Originally Posted by snoeproeAre you willing to take that chance by leaving slag in on a weld test?
Reply:Frankly, it's never been a problem for me. Every single test in my professional career has been x-ray or some equally revealing non-destructive method; never destructive. And I pass those just fine.In my opinion, destructive tests are for welding students and other amateurs. They amount to a pile of beans in the professional world. Welds can pass bend tests all day long and still fail x-ray. Originally Posted by snoeproeYou are allowed a 1/8" crack to open up on a bent test. It only takes a tiny amount of slag left in a weld to get that 1/8" crack to show up. Are you willing to take that chance by leaving slag in on a weld test?
Reply:It depends on the test. AWS D1.1 1" Unlimited plate test allows a grinder, for example.On the other hand, AWS D5.1, the bridge code, does not permit any power tools whatsoever. Originally Posted by CEPJason on structural welding tests in Canada are you allowed to use a grinder? Only time I’ve been allowed to use a grinder on a test was when doing 6-G pipe. Never on a plate test. I’ve taken some tests where they wouldn’t let us use a power wire wheel.
Reply:Xray sees it all no slag permitted weld is polished marked and shot twice examined by CWI and radiographer, third party inspector and sent to city or state in New York and they are kept forever.
Reply:Majority of the time when we tested on the job site the plates / pipe were UTed right there. If they were clear, then the plates / pipe went to the testing lab.Don’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400xray does not see it all.  There are many instance in which it doesn't.  For example, very tight lack of fusion.  It is however good at seeing defects that have volume.
Reply:Would you continue to see a doctor, if he Effed up the first time he sutured a wound closed, and so decided to stitch right over the old stitches?
Reply:Originally Posted by CEPJason on structural welding tests in Canada are you allowed to use a grinder? Only time I’ve been allowed to use a grinder on a test was when doing 6-G pipe. Never on a plate test. I’ve taken some tests where they wouldn’t let us use a power wire wheel.
Reply:Originally Posted by Hillbilly WelderFrankly, it's never been a problem for me. Every single test in my professional career has been x-ray or some equally revealing non-destructive method; never destructive. And I pass those just fine.In my opinion, destructive tests are for welding students and other amateurs. They amount to a pile of beans in the professional world. Welds can pass bend tests all day long and still fail x-ray.
Reply:How many times are y'all gonna repeat this misinformation??YES, even when they're being shot with x-ray, there is an allowance for slag inclusions and porosity. The parameters of the allowance vary by test, but there IS some allowance for inclusions in your weld. Originally Posted by PavinsteelmanXray sees it all no slag permitted weld is polished marked and shot twice examined by CWI and radiographer, third party inspector and sent to city or state in New York and they are kept forever.
Reply:This is correct. UT is, however, effective at finding lack of fusion, but it has its limitations as well. No one testing method is perfect. That's why there are so many. Originally Posted by Poptmxray does not see it all.  There are many instance in which it doesn't.  For example, very tight lack of fusion.  It is however good at seeing defects that have volume.
Reply:Well, go ahead and disagree all you want. There's a reason that x-ray is the industry standard if you want to weld for the oil companies, in a nuclear powerhouse, etc. At least in this country. I don't know how Canada works, and nor do I care.A bend test puts more stress on your weld? No ****, Shirlock. By definition, a non-destructive test does not stress your weld at all.A bend test also examines only a portion of your weld. An x-ray examines the entire weld. If you're bend testing an AWS D1.1 1" unlimited plate test, then yes, the bend test will reveal everything in the two 1/2" thick coupons you bend. There's a LOT of weld left unexamined in that 6" weldment.You know you can't hide slag or porosity from an x-ray either, right? Originally Posted by snoeproeI disagree. I find X-ray a piece of cake compared to a bend test. A bend test puts much more stress on your weld. Weather it's a sched40 pipe or 3/8" plate, a bend test reveals everything and stresses the weldment much more than a X-ray. You can't hide slag, incomplete fusion or porosity in a 3/8" plate test that's cut up and bent.
Reply:This is the structural welding test given around here. For years it was 2-G, 3-G, and 4-G. Then all of a sudden they dropped the 2-G. This test is for SMAW, and both shielded, and self shielded flux core. Over the years I’ve been told by welding inspectors that a side best test is harder to pass than a root and face bend. Attached ImagesDon’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:X-ray is only as good as the tech reading it, same as medical x-rays. Some tests give you the option of a bend test or an x-ray. Each has it's own +'s and -'s. X-ray can show a flaw that might not even be in the test bend and sometimes a good looking weld can fail a bend test. That said, tests done for initial qualifications and not a specific company generally have some tolerance. B-Pressure in Alberta used to allow for a total combined flaw not exceeding 1/8". If you were just slightly over with 1 flaw (less than 5/32") and all other bends were flawless they would pass you. BTDT, the inspector said he wasn't taking out the micrometer to measure it. LoL Now in the real world, at least Alberta, on the job is a different story for the most part. If you have a flaw, they make you repair it no matter how minor. I've had to run a bead around the top of a fillet weld on 24" pipe because the inspector said it was undercut. It was mill scale. I've also heard they've made the pressure tests a lot easier with less bends and I think they only do 2 side bends on thin strips for the renewal test on 2" pipe. Before they used to cut wide strips and do 2 root bends and 2 face bends. Apparently they want to make it easier to pass to get more people in the trade.
Reply:Yes, easier to get in the trade, so that there is more competition for the job. Meaning cheaper labor force.
Reply:Originally Posted by Hillbilly WelderHow many times are y'all gonna repeat this misinformation??YES, even when they're being shot with x-ray, there is an allowance for slag inclusions and porosity. The parameters of the allowance vary by test, but there IS some allowance for inclusions in your weld.
Reply:In what way am I "leading the new guy astray"? This is the closest I got on the matter, and you're welcome to try and tell me what portion of it is incorrect:Slag inclusions are never desirable, but up to a certain point they are acceptable.In limited amounts, in certain situations, leaving some slag in the weld IS okay. That's a fact. Informing him of that is not "leading him astray" at all. Telling him that leaving slag in is "never an acceptable practice" is the misleading statement, because there are exceptions to it. Leaving slag on a fill pass with 7018 on high pressure pipe is not a good idea, because burning it out of the toes is a bitch and 7018 sucks at burning its own slag out. If you're downhilling a 24" pipe joint on a cross-country transmission line, leaving slag in the weld IS the standard procedure and, in fact, you'll be left behind if you dick around cleaning all the slag out of every pass. EXX10 has an easier to remove slag coating, and it's also a much deeper penetrating rod that has an easier time burning out slag. When you're in that type of scenario, you hit each pass with a buffer wheel to knock the big chunks off, and weld the next pass. In this scenario, "purposely leaving slag in the weld [is] the right way to go."Likewise, if you're welding up some low-pressure water pipe that's only going to see a few pounds of pressure, and it's all just being visually inspected, it's okay to leave some slag behind for the sake of speed. Slag inclusions here and there are much more tolerable in such a scenario because they're exponentially less likely to contribute to weld failure in a 50psi water main than they are in a 6,000psi steam line.To teach the new guy properly requires that we tell him that, as a general rule, no you don't want slag in your welds. However, there are allowances for slag inclusions in all commonly used welding codes because engineers have determined that up to a point, defects such as slag inclusions aren't detrimental enough to significantly reduce the strength of the weld, and because we are human, and we will not be depositing 100% inclusion free welds all the time. There are also specific instances (such as downhill pipe welding as discussed previously) in which leaving some slag on each pass is the standard procedure, because it's burned out with the next pass. It's not foolish, it's standard procedure in many jobs.That's my best statement on the matter, no misleading information included. Originally Posted by snoeproeThe confusing part of your statements in this thread is that your basically telling the op that leaving slag inside his weld is ok and an acceptable practice. He's asking us if leaving slag in his weld, then welding over it is an ok practice. We both know that leaving slag in a weld and welding over it is not in our best interests. Let's not lead the new guy astray here. We have to teach him right. And purposely leaving slag in a weld is not the right way to go. That's just foolish and your asking for trouble.
Reply:I stole these pictures off another site. I think this was more of lack of fusion, than slag. Either way, this is what can happen on a bend test. Attached ImagesDon’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:Yes, that's lack of fusion. The layers separating from each other in the second picture, and the long crack along the toe of the face in the first picture, that's all lack of fusion. A slag inclusion will be a small hole with a crack growing from it, typically from 1/16-5/32" in length. With good eyes you can sometimes see the slag.