MIG welding aluminum arc

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I've done a decent amount of MIG welding on aluminum, usually 1/8" or 1/4" tubing and angle. I know everything is much more important to be right on, on aluminum, such as gun angle, stickout, gas flow, etc. So I start at the recommended settings and it's much more like short circuit, not spraying. If I turn the wire up, it only gets worse. Now I know with steel, you need to go way above the wire feed to short circuit in order to spray, but is aluminum the opposite? Is the wire supposed to be low enough that it almost burns back into the tip if you turn the wire feed down even more? My spool gun is pretty loud, but I don't hear that hissing sound from spraying, sounds more like a buzzing or humming sound.John 3:16(2) Miller Pheonix 456(2) Millermertic 252Dynasty 210DXHobart 210MVPDoringer D350 SA Cold SawScotchman 350LT Cold SawWebb 10x50 MillWebb 15x40 LatheGeka Bendicrop Ironworker
Reply:Aluminum has to be spray transfer - if it's stubbing into the workpiece or welding in short circuit, then either turn up the voltage or turn down the wire feed speed until it sprays.Good luck  (spool gun aluminum is not my favorite)Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:Maybe that's where I'm confused. Don't you turn the wire feed up to spray with steel wire?John 3:16(2) Miller Pheonix 456(2) Millermertic 252Dynasty 210DXHobart 210MVPDoringer D350 SA Cold SawScotchman 350LT Cold SawWebb 10x50 MillWebb 15x40 LatheGeka Bendicrop Ironworker
Reply:Aluminum or steel, spray requires voltage and adjust WFS as needed based on wire size.  That being said, WFS is typically on the high side for spray due to the higher deposition rate of spray transfer but it still requires higher voltage than short circuit for a given wire size.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:Alu mig should have almost a bacon sound to it you most say if it doesn't hiss like spray welding steel it's not right but Alu is a diff mat diff property's then steel you have to move fast I can lay down 2ft of Alu weld in the same time most lay down 6inch of steel.
Reply:Two other things not mentioned1) Wire feed.  You need a very consistent feed.  If the wire is slipping you will not be able to get a steady arc.2) Work distance.  Work distance with aluminum is much higher than with short circuit.  Approximately double. 3/4 to even 1".  Some people use recessed tips to help keep shielding gas in the area.If you are watching the puddle, you should never see the wire in the puddle.  More like spray painting.  This is a pretty hot process and it is typically only done in the flat.  One of the key reasons to add pulse to MIG is to allow out of position aluminum MIG.Gas of course pure argon.  Typically flow on the high side because of the increased work distance/stickout.  If you try to do this with CO2 or even C25, you will not have enough voltage.And stuff I assume you know:  Voltage should be 2-3 Volts more than steel (C25 settings) - wire speed is also higher. (bottom line, much more power for same thickness)  Push only gun direction etc. etc.Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:Originally Posted by con_fuse9Two other things not mentioned1) Wire feed.  You need a very consistent feed.  If the wire is slipping you will not be able to get a steady arc.2) Work distance.  Work distance with aluminum is much higher than with short circuit.  Approximately double. 3/4 to even 1".  Some people use recessed tips to help keep shielding gas in the area.If you are watching the puddle, you should never see the wire in the puddle.  More like spray painting.  This is a pretty hot process and it is typically only done in the flat.  One of the key reasons to add pulse to MIG is to allow out of position aluminum MIG.Gas of course pure argon.  Typically flow on the high side because of the increased work distance/stickout.  If you try to do this with CO2 or even C25, you will not have enough voltage.And stuff I assume you know:  Voltage should be 2-3 Volts more than steel (C25 settings) - wire speed is also higher. (bottom line, much more power for same thickness)  Push only gun direction etc. etc.
Reply:Turn heat up and keep wire speed slow. It takes more volts to weld a 1/4 piece of alum compared to steel. This is because aluminum is a big heat sink. Push gun angle. I use a whip and pause technique to make defined ripples and to prevent burn threw. There should be no spatter. And the black soot should just be along the edges of the weld not the bead itself. I find vertical and overhead alum mig to be a lot easier than steel mig.
Reply:On 1-8 inch aluminum with .035 4043 wire 21 volts and 350 - 375 wire speed should get you close . I use about a 3-8 to 1-2 inch arc length with up to a 45 degree angle on the push . One of the bigger problems on vertical is getting good gas coverage.Miller xmt304,  Miller S22 p12, Miier Maxstar SD, Miller 252 w 30A, Miller super32p12, Lincoln Ranger 9, Thermal Arc 181I with spoolgun, Hypertherm 10000 ,Smith torches. Esab 161lts miniarc.