tried gas and have some questions.

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Converted my mig to gas this past week. I got 0.035 aluminum wire and the Argon. Got the 0.030 solid wire and some 80/20.I brushed the aluminum with stainless and cleaned with some acetone. It was very thin metal and I mees with some amps and wire speeds. I kept getting burnback on the tip and zero penetration really. Do you have to preheat Al all the time? I can see with some 1/8 maybe. Is my wire speed too slow and my pass too slow or is my 30 CFM of argon not enough?Doing steel... I use the same 30 cfm, solid 0.030 wire and the welds look like puddles of snot compared to my flux cored ros of diamonds (no dimes yet). Adding more wire, les wire. Changing amps etc. seemed to not yield as deep a penetration as I had with flux. This was done on a turbo downpipe I have of mild steel . Just laying beads learning the nuances of my new mig.I'm using a Decastar 135e. Sure it's budget but I'm not building boats or anything. From my feel is think I don't have enough amps to just blaze away as a rookie. Surely I can adjust some technique or equipment to weld a bit thicker steel or weld ANY Al.AL:I have no birdnesting with the aluminum 5356. Would switching to 4xxx be better? Adding Helium to my gas mix for a hotter flame?STEEL:Smaller wire or more gas?Last edited by cosworth; 06-16-2004 at 04:24 PM.The safe path leads to stagnation
Reply:I'll get started here and better aluminum experts can add or amend.Was it a clean stainless brush that you used?  Used only on aluminum?Try upping the wire speed.  The burnback leads me to believe it was still too slow.  Preheat probably always helps on the starts.  Aluminum is such a great conductor that it will preheat ahead of you once you get going.30 CFH (I'm sure you meant H, not M) should be more than enough.  You can probably cut back to less than 20; you're problem isn't here.For both the steel and the aluminum, did you change your polarity for working with the solid wire?  DCEP, electrode positive (reverse polarity) for solid wire.  DCEN, (electrode negative or straight polarity) for flux-cored wire.You will NOT get the same penetration with solid wires that you were capable of with flux-cored wires, BUT you should get adequate penetration for your projects if you find the right settings.  If the polarity was correct, try upping the voltage to the next tap; I don't know your machine.Is there any kind of settings chart with your machine?  What are the ranges on the dials?  We can probably give you starting values to work with based on machines of similar size.Helium is not your answer unless you were already an expert trying some heavy stuff with a professional machine.
Reply:Yeah the polarity was right. And I used a brand new brush only lightly brushing in one direction to get the AlO2 off (until shiny). I'll try canking teh speed up on my wire AND my pass with some good 250f preheat. I have a good pyrometer to use.The Decastar is a Ryobi welder as well. It's 86 amps at %20 cycle. Yeah, I know, 150 minimum for decent Al welding. But I am only planning on doing sheet for now.I do need practice yes. I need to learn the welder as well. I'll back off some gas and try f faster feed and pass with plenty of pre-heat and see if that can tidy things up.From what I see self-shielded is great for thick stuff - use gas for thin pretty stuff.The safe path leads to stagnation
Reply:i just started learning myself. i can say flux is much easier to learn.mig takes some getting used to, more particular.and exhaust pipe, being round, is much more difficult than flat.put your cfh at around 15-20. and get some flat to practic on.my flat welds look pretty good, the pipe welds need some work.keep practicing, and good luck.97 S10 excab, VORTECH supercharger, fmic.a broken down 13.8 @ 97Lincoln SP135 PLUS
Reply:I have lots of bar stock to play with too. Tried some 90deg welds. Seems I have to perfect my gun angle, work angle and try to get used to using backhand. I'm left handed and I naturally go for the forehand technique with too much gun angle.AL:I'm going to try adding some wire, slowing down the bead a bit, lowering the CFH to the ball betweeen 15-20 and using backhand with a proper gun angle. Making sure my work angle doesn't allow in air under the argon.Steel:Just piss around with my angles and my wire speed. Lower the flow to the same as my argon tank too. And get the hang of doing the back hand technique using my left hand. Any other lefties out there starting out with MIG?The safe path leads to stagnation
Reply:are you pushing or pulling your gun??StangnetShop Full Of Stuff. Joey
Reply:I was pushing only (forehand). With too much gun angle and possibly too much gas.I'm a leftie and I was going left to right without being able to see the weld puddle.The safe path leads to stagnation
Reply:for anyone just starting out:Gun Technique. The most common technique is the push method (also called the forehand or leading method) that involves pushing the gun away from (ahead of) the weld puddle. Pushing usually produces lower penetration and a wider, flatter bead and can help when welding thin materials. The other common technique is the drag method (also called the backhand, pull or trailing method), in which the welding gun is pointed back at the weld puddle and dragged away from the deposited metal. Dragging typically produces deeper penetration and a narrower bead with more buildup.The safe path leads to stagnation