Difference in welds

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I lurk on the board quite a bit and have posted only a couple of times in the past. Now I have what will likely be a silly question. Why is it that some of the welds I see photos of are almost flat with the peice being welded, sort of gouged in, and others have a substantial bead. Both types are made by experienced welders. Is it technique or machine type, heat maybe?
Reply:Are you referring to the cross section of the bead? How some are convex and some concave?A weld can be a little on either side, convex/concave and still be a good weld.The process used, the type of joint, and the operators technique are all variables that when added together usually make for a unique combination.Yup
Reply:Thanks Burnit, that's what I'm referring to. Both seem equally strong. I've tried to figure out how to do the flatter welds but haven't been able to yet. Mine always end up with a fairly substantial bead.
Reply:If you're doing a butt-weld (2 pieces side by side) gap the pieces apart and/or bevel the edges.  The weld will penetrate down to the root (which is how it should be anyways) and then you just fill it till the groove is full and top of bead is just a bit more than even with surface of metal.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:Originally Posted by DesertRider33If you're doing a butt-weld (2 pieces side by side) gap the pieces apart and/or bevel the edges.  The weld will penetrate down to the root (which is how it should be anyways) and then you just fill it till the groove is full and top of bead is just a bit more than even with surface of metal.
Reply:Yes I am aware fillets do not need, nor do they normally have, complete joint penetration.  I was speaking of butt joints, as I had specified in my post.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:Originally Posted by hvwI lurk on the board quite a bit and have posted only a couple of times in the past. Now I have what will likely be a silly question. Why is it that some of the welds I see photos of are almost flat with the piece being welded, sort of gouged in, and others have a substantial bead. Both types are made by experienced welders. Is it technique or machine type, heat maybe?
Reply:I was thinking about this yesterday while I was out makin' a mess.I must have made around 20 some welds on some tubing.  Each one looked a little different.  While the heat(amps) were identical for all welds, other variables came into play.  Travel speed, differences in quality of the fitup, and also how my body was positioned (I have a tendancy to weld different depending on whether I'm welding to the left or right side of my body)I mostly seem to work with square tubing, and the conditions vary second by second.  Tubing also presents a unique problem.  It's a full penetration gapped joint with one shoulder capable of taking a lot of heat, while the adjoining butt is thin and easy to burn or cut back.If the fitup is bad you can literally dump almost 2/3 of a rod into the joint filling the gap, and sometimes have to fill it in 2 passes if the gap is really bad().  I've noticed that I have a tendancy to pile metal on this kind of deal, so the bead is slightly to major league convex.Other times you're boppin' along thinkin' "Boy, I'm the GREATEST weldor on the planet", and you burn back an edge on the butt piece of tubing.  Now you're back to dumpin' rod in the gap.  Slightly convex again.If all goes well, which it seldom does for me, the bead is almost flat from butt to shoulder with a slight rise to it and no undercut.  I've also noticed that different types of rods will form beads differently.  Fast freeze rods like 6011 tend to pile metal, while fill freeze rods like 7018 tend to leave a flatter bead.Generally speaking, if you're seeing piled metal you might wanna turn up the heat.  If you're seeing overly flat results and a lot of spatter, you might wanna turn the heat down.And if you burn through, you might wanna get another piece of metalWell, that was a perfect waste of cyberspace  Got up to damn early, and got nothin' better to do Attached Images"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Samm, that weld that goes right in the groove formed by the curved side of the tubing on one side and the edge of the end of the tubing joining it on the opposite side usually makes for a very nice flat weld.   Here is the joint you drew welded, turned 90*.   I did this in the flat position with pulsed mig.  The frame was part of a piece of gym equipment.Here is the fillet-Though not necessary, I prepped the joint with a bevel on the fillet side too-Last edited by DesertRider33; 02-15-2009 at 08:35 AM.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:Hey, I saw the welds just before I started out the door this mornin'.  Those are some beautiful welds.  The MIG in good hands does a great job.  I sometimes wish I had the equipment, and a enclosed place to use one.I took a bunch of pics typical butt and fillet welds to illustrate what I was talkin' about this mornin'.  Chiefly the variance from weld to weld depending on fitup, etc.All are on 11ga 3x3 tubing.  7018 at 105amps DCEP.  All tubing is torch cut with slight fitup issues.  I usually am a little off when I mark the tubing so it's not always square.First are a series of butt welds.  I don't know how other guys do it, but I like to direct heat into the round shoulder and middle, letting the metal fill the gap, then direct heat into the thin butt and undercut it, then slightly push metal back into the undercut and up over the top of the steel.  Dunno it it's the right way to do it, but is seems to work for me  I guess I just have a thing about not seeing any undercut on the thin side of the joint.  I makes me nervous considering it's only 11ga.Some shots are straight on, and others are off to the side to show the profile of the weld.There's more to follow.  I tried to get as many as possible to show the variance between welds. Attached Images"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Some butt welds on 2x2 11ga.  Same amps.  I have an easier time with the smaller tubing becaus the shoulder radius is more square, and there's less of a gap to fill. Attached Images"Any day above ground is a good day"http://www.farmersamm.com/
Reply:An assortment of fillets.  I varied the amps from 115 down to 105 ****s and grins.  Slowing travel speed made up for the difference.So, anyhow the OP can see the variance in welds made on one project at the same time but under tiny lil' different circumstances.I tried to get as many as I could to post.  I don't think I repeated any. Attached Images"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Whats up with the penny? Is that how bad the economy has gotten or is that what you got out of Obamas stimulus package?
Reply:Why DCEP and what are you building?A butterfly without wings, is just an ugly bug
Reply:heh..Im sure its just to show how much build up he got on his pass.. Not enough or too much build up are both weld faults.
Reply:Originally Posted by Magnetic MechanicWhy DCEP and what are you building?
Reply:Nice work Samm  The dime is Zap's trademark.   Maybe the penny is Samm's... ?   Maybe I should have included some pocket lint in my pics, since that's all I got in my pockets now...MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:Dime or penny eiither ok to show up against the weld.  Pocket lint I can relate to that. That or a pockets full of receipts.Co-Own CNC shop:Miller :1251 plasma cutter, MaxStar 700 TIG/Stick, & XMT 456 Multiprocess Welder.&  2 Hypertherm HPR260's Plasma CutterSorry I had a bad stroke but now I am back.
Reply:Oh nice welds desert! What type of gym playground gym equipment are you building?Co-Own CNC shop:Miller :1251 plasma cutter, MaxStar 700 TIG/Stick, & XMT 456 Multiprocess Welder.&  2 Hypertherm HPR260's Plasma CutterSorry I had a bad stroke but now I am back.
Reply:Thanks.   It was a workout gym in a cross-fit gym where they do mostly body weight exercizes.When I get a pocket full of reciepts it means I've been spending too much money lately.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op