Learned alot about my new welder!

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So I did some destructive testing (12 ton press) on a joint to see how well it would hold up. I used 1.5" .120 wall (i think) steel, notched two pieces and welded them up to make an intersection. First joint failed pretty bad, it looked great but was way to hot and cracked outside the weld. I was running about 18 volts and I believe around 280 IPM. I turned her down to 17 volts and about 200 ipm (where I felt most comfortable with feed rate) and she held up alot better, but still cracked. I was leaning on the press pretty good this time. Now what makes the most sense is to find the right voltage and make the strongest joint eh? I was thinking going around 16.5 volts and trying some more. I just realized how damn poweful this welder is its awesome! I am working on building some cages, I stick welded one which turned out well, but I would like to get better obviusly and safe. Anyadvice or pointers with round tube?? By the way my tubes were poorly fitted I just did a quick notch on the band saw and welded them up just to see.HTP Invertig 201Lincoln Idealarc SP250Miller 180 AC StickBy farmall:They should have held the seagull closer to the work, squeezing evenly for best deposition.
Reply:Show pics of the sections. I try to get as good a fit as I can with tube, as when you have a very large bead filling a gap, it can make for more brittle areas right on the tube next to the bead in the HAZ, and for some reason, I have seen a couple of welds crack that were large fills, right next to the base metal-maybe 3/32" in from the base .And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:Hey fordman,I have to agree with Rojo on the fitting aspect to get a solid weld joint. You need to minimize the gaps & try to get as much a "touch" fit all around as possible. The other area I feel you are having problems is the heat setting & wire feed you are using. You are much too high(heat) for that thickness. Generally, you want to have a heat setting near the thickness rule, ie. .125 thickness/125A heat to start. Then you can fine tune your WF settings to optimize the joint weld. Practice on some scrap setups & get yourself equipped to make tight, concise joint fittings and you will see a marked difference with your welded joints. Hope that helps a bit.... Good luck....  DennyComplete Welding/Machine/Fab. ShopMobile UnitFinally retired*Moderator*"A man's word is his honor...without honor there is nothing.""Words are like bullets.... Once they leave your muzzle, you cannot get them back."
Reply:I ASSume    from your sig you have an SP250.  What gas and wire size are you using?DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:pics.  where are the pics.
Reply:Maybe this will help.  .045 wire, 1 inch per minute = 1 amp.So for .120 pipe, 120 ipm would be a good place to start.For .035 wire *1.6 = 192 ipm.For .030 wire its * 2 = 240 ipm.Set your wire speed first, then adjust voltage for a good smooth arc.  If its too hot, turn down the wire speed and adjust the voltage for the best arc.  I would guess around 18 volts depending on position and gas.Is there a chart in the door of the machine?DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:I am using .030 wire and 75/25 argon c02 mix. I really liked how it welded with a bit higher voltage but I didnt like how it broke. Sure a cage in itself needs to be strong and it shouldnt see that same kind of "bending" force, but still I want my joints to be strong as I can! The second one was the lower voltage with a lot more force. I dont know the whole volt/ amperage correlation thats part of my issue.. I am still figuring it out and it seems I need to weave alot more with the welder to keep the weld puddle from getting that cold lap look. But my beads were a bit wide for my liking, at least the first one was. Attached ImagesLast edited by fordman; 02-03-2008 at 03:43 PM.HTP Invertig 201Lincoln Idealarc SP250Miller 180 AC StickBy farmall:They should have held the seagull closer to the work, squeezing evenly for best deposition.
Reply:Way to much bead...half that would be close to correct.Anything worth doing is worth doing RIGHT
Reply:Yeah thats the problem I am having with this thing right now I cant get it to "flow" right. The bead on the right is closer no?HTP Invertig 201Lincoln Idealarc SP250Miller 180 AC StickBy farmall:They should have held the seagull closer to the work, squeezing evenly for best deposition.
Reply:Still way too much heat...get a tight fit-up and see what you can do, it makes a lot of difference !!Anything worth doing is worth doing RIGHT
Reply:Ok, I will play a bit tonight and try and get a better camera. That was only around 17 volts and 200 ipm, I need to turn it down? Are you basing this off the blueing off the metal?HTP Invertig 201Lincoln Idealarc SP250Miller 180 AC StickBy farmall:They should have held the seagull closer to the work, squeezing evenly for best deposition.
Reply:Yep, basing it off the size of the bead and the HAZ.Anything worth doing is worth doing RIGHT
Reply:Ok. Maybe if I moved a bit quicker I would reduce the heat and bead size? Thanks for the help, this helps more than you think. I need a better helmet too, the 20$ OSH one isnt cutting it either!HTP Invertig 201Lincoln Idealarc SP250Miller 180 AC StickBy farmall:They should have held the seagull closer to the work, squeezing evenly for best deposition.
Reply:Originally Posted by fordmanOk, I will play a bit tonight and try and get a better camera. That was only around 17 volts and 200 ipm, I need to turn it down? Are you basing this off the blueing off the metal?
Reply:That blueing is probly an inch or so from the weld. Thats 1.5" tube. I didnt try for a tight fit up at all, I was merely curious and I did a quick notch on the band saw because I dindt wanna setup my holesaw notcher or get the chop saw!! It defintely didnt warp there wasnt that much heat into it!!HTP Invertig 201Lincoln Idealarc SP250Miller 180 AC StickBy farmall:They should have held the seagull closer to the work, squeezing evenly for best deposition.
Reply:You can't weld right if you can't see correctly. Welded for years before auto lens, just suit the shade to the task you're performing. I always kept shades from 9 - 12 before I got lazy with an auto.Anything worth doing is worth doing RIGHT
Reply:Originally Posted by olddadYou can't weld right if you can't see correctly. Welded for years before auto lens, just suit the shade to the task you're performing. I always kept shades from 9 - 12 before I got lazy with an auto.
Reply:An auto lens is a luxury, not a requirement. You can get fixed shade lens for less than $10 each, find the one that best suits your personal vision and have at it. For a lot of vision impaired folks, back-light makes a big difference also. Set-up so you don't have an overhead light shining onto the backside of the helmet, makes a big difference !!If you're only hobby welding I'd wait to get an auto lens...several tools that would serve you better than a fany lense.Something else to note is the wire you're using...some machines just flat don't like some wires. Go for 1 or 2 pound spools until you know which wires are best suited to what you're doing. And don't bother with any more practice until you get your notcher or whatever set up...quality work doesn't happen by accident.Anything worth doing is worth doing RIGHT
Reply:I have a notcher and am pretty good with a chopsaw as well. Like I said a few times I just did a quick notch to practice on and see what happened. With a stinkin bandsaw! It workd fairly well actually they werent horribly fitting at all, Snug everywhere, maybe an 1/8" gap on one of the sides!HTP Invertig 201Lincoln Idealarc SP250Miller 180 AC StickBy farmall:They should have held the seagull closer to the work, squeezing evenly for best deposition.
Reply:Originally Posted by olddadSnip...quality work doesn't happen by accident.
Reply:Let us know how to progress with these welds.  I never could do a nice weld with MIG on tubing so I went to TIG and it was much easier.  I am still learning ti fill a little better, but for the most part the first few TIG welds I ran in TIG were better than anything I was able to do with MIG.Build a Barstool Racer at BarFlyRacers.com!
Reply:Yeah but tig seems harder to do in car. I mean if I was building a bolt in bar or something I wouldnt mind tig welding it.HTP Invertig 201Lincoln Idealarc SP250Miller 180 AC StickBy farmall:They should have held the seagull closer to the work, squeezing evenly for best deposition.