Help with 7018 hot pass & filler

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I've been working on my horizontal v groove open root in class, and so far it's been kicking my butt. The root I can run no problem, it's the hot pass and filler. I'm having a hard time running it and getting slag off without having to beat it off every time on both the hot pass and filler. I've tried so far anywhere from 82-90 amps at roughly a 30* angle with a slight lead. I tried that today at my shop and also tried playing with the dig function and still couldn't get what I needed. The bead I felt looked okay, I got a picture if that helps, but if anyone could even point me in the right direction that would be awesome as I have tomorrow to practice on some plate before tests next week. Here are the pictures, I wasn't trying to run a full hot pass to see where I maybe was messing up or not doing something right.
Reply:7018 slag can be tough to get out of a bevel. You could try turning it up a little and skating a thin pass in there, or you can clean the slag with a grinder. Once you get it flush it should come off pretty easy. Or run two stringers instead of trying to fill it all up with one bead.
Reply:Well I would grind if I had the choice, but according to my professor who is aws certified and also a cwi I cannot grind anything after the root, so that leads me to only critique the way I run the rod.
Reply:It may be the angle of the picture, but that looks like a very tight 'V' you have beveled there.It should be 30 degrees on each side, that is, 60 degrees included.If you have 45 degrees on each side, will be hard to get a relatively flat profile.Hobart Beta-Mig 2511972 Miller AEAD-200LEMiller 250 TwinNorthern Ind. Hybrid 200Longevity Stick 140Longevity Migweld 200SThermal Arc Pak 3XR
Reply:What size rod you using. Fill pass looks fine in the pics you posted. How bout a wire wheel on a grinder, is that also not allowed?
Reply:That does look like a really tight bevel. It barely even looks like it has a bevel. Working on nozzles on thick vessels, is where 7018 slag is a real PIA. You have to use air chippers to get it off and they don't make good enough ear plugs.
Reply:Are you using a 3/32 rod? If so I would run 100amps. And a grinder with a wire wheel star shaped attached. Then a pneumatic air gun to blow away any loose wire wheel debris and slag dust.Last edited by All positions; 01-25-2015 at 05:04 AM.
Reply:I would run 3/32 rod.  Run one pass from the bottom of the bevel half way up the root.  Clean thoroughly with your chipping hammer, maybe an awl.  Next pass run a bead and tie in the pass u just ran and fill it up to the top of the bevel.  I would run my amps around 96, the slag should come off very easy.  Hope any of that helps. One more thing use a stainless steel hand wirebrush if u can.  Good luck dude!Last edited by Murphy's law; 01-25-2015 at 05:42 AM.Reason: add more
Reply:Thanks guys! I will try any and all advice given. I don't think they mind a wire wheel, I have one I can throw in my bag for class. I was using 3/32 rod, I forgot to mention that, and the plate was pre beveled that our school bought and my professor gave me some at the end of the semester, I believe it was a 42* bevel for some reason, I did try grinding some more out of it when grinding my lands.
Reply:You may want to throw a hammer and chisel in your bucket too. A chisel can be a big help in getting slag out. 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:It appears you have slag trapped in the upper toe of the weld. You may have incomplete fusion up there. In which case, you will likely burry slag in there on your next pass. That will result in a failure if this piece is to be cut up and bent for evaluation as a crack will open up. If I were you, I'd be running hotter and ensure you get your  puddle to wash into the top plate consistently as you go along. Sometimes a J motion with your rod will help with this as you move along.Run a wire wheel on your angle grinder over every pass on something like this. You can't leave slag anywhere in there then weld over it. It will open up as a crack in a bend test. I also see chipping hammer marks on the plates. That's another no no on a weld test. A wire wheel on a grinder is your friend.Depending what you started out with as a root gap, you may have to do it in 2 passes if you can't get complete fusion on both plates with one pass.Last edited by snoeproe; 01-25-2015 at 08:25 AM.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:I have a 4.5" grinder with a SS wire wheel in my booth at school. I use it between every single pass. It is considered the same as a wire brush. (just faster). If you are having a hard time getting the slag off a 7018 stringer try slowing down. For my 2G with backing I used a 3/32 7018 @90A for the root. 3/32 7018@85A for the hot. 1/8 7018 @ 120A for the fill, and 1/8th 7018 @ 115A for the cover. I keep notes on all my settings.HF 98233 Stick/TigHF  95136 PlasmaEastwood TIG200Eastwood MIG250Damn, I cut it twice already and it's still too short!
Reply:I'm sure it's different everywhere, but I've taken numerous AWS D1.1 structural welding tests. No power tools allowed at all!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 open root 6010, 1/8 land and root. From then on out to the cap is 7018 3/32.
Reply:Originally Posted by JSMotorsportsThis is open root 6010, 1/8 land and root.
Reply:Originally Posted by CEPMust be something like this?
Reply:looks like a 90 degree edge to me which is why you're having problems. to get into tight quarters i sometimes use a dasco steel scratch awl and a couple specially ground hacksaw blade sections.i.u.o.e. # 15queens, ny and sunny fla
Reply:The CWB structural test here allows you to use a wire wheel. No grinding but you can use a wire wheel for cleaning.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:There is a bevel! I will get the angle of it exactly when I get to the shop later today. I have one left that's tacked up. Then I can shear the plates and flip them around and do it again.
Reply:Originally Posted by JSMotorsportsThere is a bevel! I will get the angle of it exactly when I get to the shop later today. I have one left that's tacked up. Then I can shear the plates and flip them around and do it again.
Reply:An old wood cutting sawzall blade works good to rake out small bits of slag. If you can find a real stiff wire brush may also help.
Reply:Originally Posted by geezerbillAs another poster said, considering the apparent narrow vee, the last weld does not look very bad, really. It could have a little smoother tie in at the edges.I am unclear as to which passes we are looking at. Is it the root, and the hot pass, or the hot pass and the first filler pass?If the pass you are covering up is the root, you could have spent more time grinding, making sure there are no lines(wagon tracks) above or below the weld.If it is the hot pass, it is too humped-up, with lack of fusion, or cold roll, or whatever you want to call it at the edges. this introduces the real possibility of slag getting trapped in that crevice, on the subsequent pass.Either way, I would turn the machine up, and hold a little longer arc, to let the heat and weld deposit be spread over a little wider path, with the intent of having the puddle spread more evenly among the bottom bevel, the previous pass, and the upper bevel.As an old salt worded it to me, decades ago, "turn it up, back off, and let it fly on..."How thick is the steel used for the coupon?
Reply:I did basically the same thing with 6” sch. 80 pipe. 5-G, 30-degree bevel, 6010 root, 3/32” 7018 for the hot pass. I had to take a needle gun to get the slag out of the groove.  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:Good lord, well I'm going to see what I can come up with today and get back to yins!
Reply:Well I think I might have found the answer to all my problems It's about 68*Looks like 23 to 24 degrees to me, but can't see all that well.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:Sorry that's what I meant, forgot to divide it, but yes roughly 24*
Reply:Originally Posted by JSMotorsportsSorry that's what I meant, forgot to divide it, but yes roughly 24*
Reply:Oh wow totally miss interpreted that there, but yes. I think that's half of my problem.
Reply:Originally Posted by MinnesotaDaveHe meant how far you are off of the 90 degree mark - about 24 degrees.What are you dividing?
Reply:Originally Posted by JSMotorsportsOh wow totally miss interpreted that there, but yes. I think that's half of my problem.
Reply:Originally Posted by MinnesotaDaveIt will help - your included angle would be 48 degrees, a lot tighter than the 60 degree included angle that is called for.
Reply:Originally Posted by MinnesotaDaveWhat are you dividing?
Reply:It looked like too small of a bevel but even with the proper bevel, slag can be tough to remove. A trick some guys use is a blade from a power hacksaw. Cut it into a smaller elongated dear drop shape. It can used for feathering your tacks(cleaning the burr off after grinding) on the root pass and the root if you need more than 1 rod. It will also work good for cleaning slag along the toes of your hot and fill passes.
Reply:Originally Posted by geezerbillIf you have 45 degrees on each side, will be hard to get a relatively flat profile.
Reply:lol that works.
Reply:I'm sure it's different everywhere, but I've taken numerous AWS D1.1 structural welding tests. No power tools allowed at all!
Reply:pffft, how you gonna take a pipe test on say inconel without a grinder?
Reply:Agree that there shouldn't be any restrictions on grinder use except possibly on cap.  Anyone can have a bad start or a 'flux disintegration'.  Also some rods just behave differently and a touch of a grinder can make all the difference.  A capability test shouldn't involve luck.  Never been refused the use of a grinder on the job.Last edited by OldSparks; 01-27-2015 at 11:44 AM.