Slag on my shoulder

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Condition: Welding a tee-joint with square tubing, 2.5" x 0.188 Electrode: 1/8" 7018AC @ ~125APosition: HorizontalSo I'm trying to figure out how to finish up the shoulder welds on this square tubing.  What I am doing (after I put fillets on the flat corners), is to build up the shoulder on the bottom piece, chip off the slag, then come along and weld the top piece to the weld. Unfortunately, the buildup on the shoulder leaves slag between the weld and the bottom edge of the top piece, that even a cup brush won't reach, as you can see in the following image:Any ideas as to how I can remedy this situation?  Thanks,Jon
Reply:Maybe a 6010 first pass to fill the gap. Anytime you leave a 'V' crevice, you will trap slag. You can remove it with a skinny wheel, but the best thing is not to have it in the first place.UA Local 598
Reply:use a broken hacksaw bladeMillermatic 211weldpack 3200 squirtgunsquare wave 200victory journeyman kitHypertherm 30xptoo much other crap to listtinkerer extraordinaire
Reply:Fill the gap in first and then cap it off. In your situation use a hacksaw blade as was said or a zipcut on a minigrinder, (I'd go with the zipcut)....Mike
Reply:Originally Posted by WHughesMaybe a 6010 first pass to fill the gap. Anytime you leave a 'V' crevice, you will trap slag. You can remove it with a skinny wheel, but the best thing is not to have it in the first place.
Reply:Use your chipping hammer as learned in school and the better you get the less you'll use it LOL    Well really like was said better root fill and a cap to keep it smoother and trap no junk good luckBETTER FIT UP YUP LEAVE NO GAP AND THERE YA GOLast edited by Tony D; 09-12-2010 at 09:06 AM.Reason: fittinLincoln 225 Tombstone,Miller Big 20,Hobart 180,150' Argon,A/D hobart hood 22 Ton Log splitter,79 F350 dump eats 4.75 TONS and still turns cutters,grinders,And a  Hypertherm POWERMAX 30
Reply:Forget about welding one side and then the other.  Put in a root that fuses both sides, then fill it with another pass or two on top until it's flat.  Slag hammer, scratch awl/pick, wire brush and wire wheel can all be used to remove the slag.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:im gonna  ask a question thats related, not hijacking...if you put in a 6010 root pass, you can brush out almost all the thin black slag..does it need to be ground out or willa  7018 hot pass float it up?
Reply:Originally Posted by jonnycatUnfortunately, the buildup on the shoulder leaves slag between the weld and the bottom edge of the top piece, that even a cup brush won't reach... Jon
Reply:Originally Posted by weldbeadim gonna  ask a question thats related, not hijacking...if you put in a 6010 root pass, you can brush out almost all the thin black slag..does it need to be ground out or willa  7018 hot pass float it up?
Reply:Use a grinder? This isnt rocket science.Using an engraver would be like trying to carve a totem pole with a paring knife. Have we all gone mad?
Reply:Originally Posted by jonnycatSo what technique would you use?  Mind you, this is going to be AC welding in the horizontal position.  I don't have a lot of experience welding up gaps).   Thanks
Reply:That size of tubing can have one heck of a rounded edge so there will be a pretty big gap on the 1st pass, and that 1st pass in that position should be conservative. Fill the open space and tie the edges 1st pass around. Don't try and do it all in one pass. Fill the rest in the 2nd pass. Carefull, a gap like that is going to pull like crazy. Give it some time in between passes. Find something else productive to do while it cools a bit."The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:bigger rod, little more juice and point the stick up into the joint... weave up n down as you move to keep the width of the puddle proper... or, cellulose root it and then come back over with lohi... you dont need a cannon to kill a mosquito.nothing fancy, just a few hot glue guns for metalwww.sicfabrications.com
Reply:If you're more comfortable fitting than welding you could always cut two opposite sides shorter so the other two sides at 90 deg hang down a bit more. Looks similar to a coped pipe joint, I've done that on larger square tubing 4">, it's called cheating :-)...Mike
Reply:Originally Posted by WHughesFire up the 6010 and establish a weld puddle that includes both pieces of metal. Its ok to move the electrode to get both edges. The square edge of your branch will try to open up or eat away, at that point move out to let puddle freeze then move back in. You will be left with a somewhat concave 6010 weld. Wire brush the slag and go over with 7018.Good luck, maybe post more pics.
Reply:Originally Posted by SandyThat size of tubing can have one heck of a rounded edge so there will be a pretty big gap on the 1st pass, and that 1st pass in that position should be conservative. Fill the open space and tie the edges 1st pass around. Don't try and do it all in one pass. Fill the rest in the 2nd pass. Carefull, a gap like that is going to pull like crazy. Give it some time in between passes. Find something else productive to do while it cools a bit.
Reply:Okay, I ran some more welds today, and took a few pictures.  First I used a 3/32" 6011 rod for the root, which added a difficulty as I have never been able to run that rod before (nor is rod manipulation my strong suit).  It's not close to perfect, but it's a lot better than when I started out:It looks like there is some slag trapped within some of the "Cs", I'm guessing that is the result of inconsistent technique.The other thing I played around with was using the 1/8" 7018AC, but instead of focusing it on the shoulder, I just kind of aimed it into the gap, keeping at a speed that just melted the outside edge of the top piece:That actually seemed to work out okay (although I was getting tired at that point), but I don't know if that technique is one that produces sound welds.
Reply:Dont worry about the slag left in the first pic, it wont do any harm to the weld or any welds after that.  Thats pretty clean for a cellulose based electrode.Have we all gone mad?