Tell me how to perfect my beads (sheetmetal)

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This is my first time using gas, sadly (Only used about 3 passes with CO2) and first time with sheet metal (18G)Im overall pretty happy with how it turned out, loving welding with gas, its everything they've said and more, however I am wishing my beads were absolutely perfect.Any suggestions? I would like more concave and obviously I need to straighten them out and run through my tacks. Started getting the beads a little better towards the end of my battery box (pictured).Please give ideas (settings are 4 on wire speed and 2 on "amps")Hobart squirt gunAHP AlphaTig 200XCouple angle grindersGood 'Ol fashioned cajones
Reply:I was welding today and my welds reminded me of banana slugs. Im not qualified to speak to the welds, I have a hard time telling by the images. I can tell you they are welds. Regards,RobGreat Basin WeldingInstagramBlue weldersRed weldersMy luscious Table DIY TIG Torch cooler
Reply:What wire size? .024 would be my choice for something like this. C25 would be a better gas choice for thin sheet. 100% CO2 is more aggressive and deeper penetrating than C 25 is.With something like this fit up can help. If you over lap the corners, you leave no place for the weld to go.  If instead you set up the joint so just the inside corners touch, you leave yourself a V to fill. 1/16" 16 ga is most likely the smallest material you can use this on. Go any thinner and the corner is pretty much an overlap anyways. In that case I might look at changing the joint design completely. Outside corners are one of the harder ones to do well. They get really tough when you get really thin. At the tech school it's one of the last joints we have students do, just before but joints. There just isn't much space to lay down a bead when you are talking about the thickness of the material. You might find going to something like a lap joint easier. If possible fold the one side 90 deg and set it up so the piece over laps the other. That doubles the thickness to prevent burn thru on a tiny sharp edge. With thin steel, it's not all that hard to get a nice fold. They sell small hand folders for doing sheet metal duct work.( see pict) I'd have to check mine to see what the thickest material they will do is, I want to say no thicker than 18 ga. I have ones in 12", 18" and 24" and have cut a few down for custom sizes for special jobs. Tool has 2 "settings, a 3/8" fold and a 3/4" fold IIRC.With thin sheet it's also very tough to get the tacks to blend. one way is to just use the tacks as the actual weld, and start/stop at the tacks. 2nd option is to feather the tacks down to almost nothing 1st with the grinder so you don't have a big area to go over, Down side is that you need to have enough control to take away the excess material and not remove all the strength of the tack so it wants to open up when you do the weld.Last suggestion. Don't do this free hand. Set yourself up something that you can rest your hands on as you do the weld. It might be a chunk of angle or tube clamped to a box or something that you can use as a rest. This helps eliminate the shakes and helps you maintain a consistent arc length. If possible set all this up to do  the welds in the flat or horizontal fillet position to keep things easy..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:I can't see any difference in C25 or straight CO2 on low amperage. None. Downhand stuff like that.Bubble gumTooth pixDuct tapeBlack glueGBMF hammerScrew gun --bad battery (see above)
Reply:Originally Posted by DSWWhat wire size? .024 would be my choice for something like this. C25 would be a better gas choice for thin sheet. 100% CO2 is more aggressive and deeper penetrating than C 25 is.With something like this fit up can help. If you over lap the corners, you leave no place for the weld to go.  If instead you set up the joint so just the inside corners touch, you leave yourself a V to fill. 1/16" 16 ga is most likely the smallest material you can use this on. Go any thinner and the corner is pretty much an overlap anyways. In that case I might look at changing the joint design completely. Outside corners are one of the harder ones to do well. They get really tough when you get really thin. At the tech school it's one of the last joints we have students do, just before but joints. There just isn't much space to lay down a bead when you are talking about the thickness of the material. You might find going to something like a lap joint easier. If possible fold the one side 90 deg and set it up so the piece over laps the other. That doubles the thickness to prevent burn thru on a tiny sharp edge. With thin steel, it's not all that hard to get a nice fold. They sell small hand folders for doing sheet metal duct work.( see pict) I'd have to check mine to see what the thickest material they will do is, I want to say no thicker than 18 ga. I have ones in 12", 18" and 24" and have cut a few down for custom sizes for special jobs. Tool has 2 "settings, a 3/8" fold and a 3/4" fold IIRC.With thin sheet it's also very tough to get the tacks to blend. one way is to just use the tacks as the actual weld, and start/stop at the tacks. 2nd option is to feather the tacks down to almost nothing 1st with the grinder so you don't have a big area to go over, Down side is that you need to have enough control to take away the excess material and not remove all the strength of the tack so it wants to open up when you do the weld.Last suggestion. Don't do this free hand. Set yourself up something that you can rest your hands on as you do the weld. It might be a chunk of angle or tube clamped to a box or something that you can use as a rest. This helps eliminate the shakes and helps you maintain a consistent arc length. If possible set all this up to do  the welds in the flat or horizontal fillet position to keep things easy.
Reply:Beads don't look all that horrible, but they could be better. Better picts would help point out things to work on. Consistency seems spotty over the whole project. Some beads look ok, Others are sort of lumpy, other places I see a lot of porosity.Beads in pict 1 and 2 seem a bit tall. Beads on the left side of pict 3 look a bit flatter and better.As far as settings, without knowing what you are using so I can look up the suggested settings or go off similar units, it's a blind guess. 2 on voltage and 4 on wire speed is a bit different between my 140 amp class 110v mig and my 200 amp class mig. You are about in the right range from my guess. I'd sort of have to play a bit with the settings and see how they dial in. I'd go with the wire speed as slow as I could managing to keep a decent puddle. In some cases that might mean dropping down to tap 1 and reducing the wire. Other times tap 1 is too cold and I need to stay on tap 2. On my 200 amp machine tap 2 wire speed 40 is suggested for .024 wire and C25 on 16 ga, on 18 ga tap 1 and 35 on the wire same size and gas, so I'd be right between the two. My small 110v mig, works out to about the same, but the suggested wire speed is just a bit slower, 2/ 30 on 16 ga, 1/20 on 18 ga.Also remember when working on thin material, you can control your heat with your stickout. When you hold the gun farther away, you get a colder bead than when you keep the gun in tight. On tap 1 I might get up close and personal with the gun so I gain a bit of heat vs where I normally weld. On tap 2 I might back off a bit farther than normal so as to cool the bead a bit more and not blow thru. This has a lot to do with how you personally like to weld. I tend to stay in rather close most times, so running a lower tap may be the better choice for me. Other guys like to be farther away.Oh I forgot to mention, I'm talking about pushing the bead vs dragging. When you push you get a flatter bead. When you drag you get a taller bead. Also on something like this I go straight, no motion or circles or if I do the side to side motion is micro small. I'm talking about 1/64" max it's more of a super fast wiggle than anything else. Circles cause you to stay in the puddle longer and build up more material and heat, some what similar to dragging. That's really the last thing you want with thin sheet.Thin sheet metal is it's own little world. Things that work here like overlapping spots or stitches won't work with thicker stuff, but are ideal with thin sheet to avoid burn thru or warping..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:On thin stuff like 18, and 16 ga, I would make the corner welds downhill.You can weld a little hotter, and as long as you stay ahead of the puddle, the weld will flatten out, and look real nice.I would tack what I could on the inside, very small, inconspicuous tacks. That way you don't have to worry about tie ins, or welding over tacks.I would also just overlap the corners, in the case of non-critical applications like batt boxes, tool boxes, etc.
Reply:Originally Posted by DSWBeads don't look all that horrible, but they could be better. Better picts would help point out things to work on. Consistency seems spotty over the whole project. Some beads look ok, Others are sort of lumpy, other places I see a lot of porosity.Beads in pict 1 and 2 seem a bit tall. Beads on the left side of pict 3 look a bit flatter and better.As far as settings, without knowing what you are using so I can look up the suggested settings or go off similar units, it's a blind guess. 2 on voltage and 4 on wire speed is a bit different between my 140 amp class 110v mig and my 200 amp class mig. You are about in the right range from my guess. I'd sort of have to play a bit with the settings and see how they dial in. I'd go with the wire speed as slow as I could managing to keep a decent puddle. In some cases that might mean dropping down to tap 1 and reducing the wire. Other times tap 1 is too cold and I need to stay on tap 2. On my 200 amp machine tap 2 wire speed 40 is suggested for .024 wire and C25 on 16 ga, on 18 ga tap 1 and 35 on the wire same size and gas, so I'd be right between the two. My small 110v mig, works out to about the same, but the suggested wire speed is just a bit slower, 2/ 30 on 16 ga, 1/20 on 18 ga.Also remember when working on thin material, you can control your heat with your stickout. When you hold the gun farther away, you get a colder bead than when you keep the gun in tight. On tap 1 I might get up close and personal with the gun so I gain a bit of heat vs where I normally weld. On tap 2 I might back off a bit farther than normal so as to cool the bead a bit more and not blow thru. This has a lot to do with how you personally like to weld. I tend to stay in rather close most times, so running a lower tap may be the better choice for me. Other guys like to be farther away.Oh I forgot to mention, I'm talking about pushing the bead vs dragging. When you push you get a flatter bead. When you drag you get a taller bead. Also on something like this I go straight, no motion or circles or if I do the side to side motion is micro small. I'm talking about 1/64" max it's more of a super fast wiggle than anything else. Circles cause you to stay in the puddle longer and build up more material and heat, some what similar to dragging. That's really the last thing you want with thin sheet.Thin sheet metal is it's own little world. Things that work here like overlapping spots or stitches won't work with thicker stuff, but are ideal with thin sheet to avoid burn thru or warping.
Reply:Here is an example of the difference between a full outside corner prep (A) and an overlapping corner prep (B).When using MIG or Flux Core on sheet metal of 16 ga or thinner (and maybe even possibly 14 ga, depending upon the application), example B is much easier to fit up, and execute with a nice, flat weld profile, which does not detract from the appearance of the box, if run fairly hot, downhill, somewhat quicklyFor thicker metal, the example A gives more strength, and also gives enough room inside to "V" for the weld to lie nicely with a little bit of a round contour, making the welded joint look almost like it has been bent.By the way, the pic came from here, just to give credit where due:http://www.soliddna.com/SEHelp/ST5/EN/i_v/shtpls1a.htm
Reply:Crap that thin? Buy a TIG lol.
Reply:This is an 18ga open corner joint. vertical down MIG .030 75/25 Lincoln 216 set to C 165. Only about 2.5" long but I could do this for feet on end if necessary but thankfully not. Sometimes I have to fill a .25" gap if the press brake operator had a bad day. Try welding your battery box joints downhill and "feed" the puddle with pulse "on" "off" stitches with the MIG gun so that you have two things working for you 1) your hand position dragging the puddle downward about .25" at a time and 2) adjust your hand position so that you alternate between building up the size of your puddle and also dropping your hand downward to help gravity pull your puddle downward. My "puddles" and slightly smaller than the size of an Advil pill. The puddle is standing above the surface of the joint so that I have something to grind down and yield a perfect corner. There are no low spots or porosity. Come to Phx and I'll give you a 15 minute lesson and you'll be good to go.example of finished cornerLast edited by Jimmy_pop; 03-11-2014 at 08:07 AM.
Reply:Very nice work there. That takes a fair amount of skill..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:It will take you a minute or two of practice to get it to look like thatBut you won't find a better example of how to get it done than that.Very nice.
Reply:Originally Posted by Jimmy_popThis is an 18ga open corner joint. vertical down MIG .030 75/25 Lincoln 216 set to C 165. Only about 2.5" long but I could do this for feet on end if necessary but thankfully not. Sometimes I have to fill a .25" gap if the press brake operator had a bad day. Try welding your battery box joints downhill and "feed" the puddle with pulse "on" "off" stitches with the MIG gun so that you have two things working for you 1) your hand position dragging the puddle downward about .25" at a time and 2) adjust your hand position so that you alternate between building up the size of your puddle and also dropping your hand downward to help gravity pull your puddle downward. My "puddles" and slightly smaller than the size of an Advil pill. The puddle is standing above the surface of the joint so that I have something to grind down and yield a perfect corner. There are no low spots or porosity. Come to Phx and I'll give you a 15 minute lesson and you'll be good to go.example of finished corner
Reply:This is a beautiful weld. It can be duplicated with a drag technique during a flat weld on thin sheet metal.Bubble gumTooth pixDuct tapeBlack glueGBMF hammerScrew gun --bad battery (see above)
Reply:Originally Posted by Jimmy_popThis is an 18ga open corner joint. vertical down MIG .030 75/25 Lincoln 216 set to C 165. Only about 2.5" long but I could do this for feet on end if necessary but thankfully not. Sometimes I have to fill a .25" gap if the press brake operator had a bad day. Try welding your battery box joints downhill and "feed" the puddle with pulse "on" "off" stitches with the MIG gun so that you have two things working for you 1) your hand position dragging the puddle downward about .25" at a time and 2) adjust your hand position so that you alternate between building up the size of your puddle and also dropping your hand downward to help gravity pull your puddle downward. My "puddles" and slightly smaller than the size of an Advil pill. The puddle is standing above the surface of the joint so that I have something to grind down and yield a perfect corner. There are no low spots or porosity. Come to Phx and I'll give you a 15 minute lesson and you'll be good to go.example of finished corner
Reply:I use .030 since I mostly work with 14 and 11 gauge tube. I do not have time to switch out rolls so my sheetmetal technique has developed to use .030. Along time ago I use to clamp a piece of .5" copper solid bar behind those corner joints to help contain the puddle but I have not done that in years. I am stitch welding, pulse on-off manually vertical downhill. I am welding more on the previous weld than I am welding on the virgin material with each pull of the trigger. Even being red hot, the slight cooling between each weld is enough to keep from blowing through. Again, I am welding more on the previous weld that the new material by a ratio of about 70/30%. 30% being the amount of the new weld going onto the joint. This keeps me "feeding" the puddle so the puddle is tall and above the height of the joint so that I have something to sand down and blend. This technique would not work well in any position other than vertical down since gravity is a major help is steering the puddle in the direction I want it to go. I could do the same thing with .023 or .035, would not really change anything.