Aluminum MIG

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With all the conversation about this subject, has anyone tried different gas mixes for aluminum MIG (DC spray & short and pulse spray)? I've been using 100% Argon and have been wondering if a mix would produce a nicer/cleaner bead? Would another type mix offer more penetraion? I'm ready for an Argon refill and am open to experienced suggestions.
Reply:I was wondering about that too, I just started using MIG for aluminum days ago. I want to find a way to make the process less tempermental. it seems like If everything isnt "just so" it wont spray or I get spatter etc...Its workin well but its seems less forgiving than other MIG stuff. If my machine isnt just right it wont spray, I want a wider envelope to work in.One part of the Lincoln Website says pure Argon only, another part of their site says up to 25% heliumI found a patent dealing with this, they are adding all types of gas to the mixcheck it outhttp://www.patentstorm.us/patents/65...scription.html
Reply:A mix with what other gas?  Some helium should make the weld hotter, allowing it to spray at a lower voltage and increasing penetration at the same voltage.  As for other gasses, I don't think I would want a reactive gas mix with aluminum.  Certainly not C02.  That would be porosity and soot city.  Not certain about oxygen.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:you can't short arc Al. Spray only. MM350P is incredibly forgiving on Al. It welds incredibly well. --Gol'
Reply:I've heard many arguements that you can't short arc aluminium, but I've seen it done and I've done it. It doesn't offer much penetration, but it will work somewhat.My thought on the gas mix was Helium.
Reply:pretty sure what ever you can weld aluminum with GTAW you can use for it6G zirconium 702 GTAW 2" xxheavy6G P.E.D. carbon steel GTAW 2" xxheavy3G titanium Gr. 2 - Gr. 7 GTAW up to 3/4" 3G 316L stainless GTAW up to 1" 3G carbon steel GTAW up to 1" 3G Hastalloy GTAW up to 3/4"1G tantalum GTAW up to .060"
Reply:Originally Posted by Go1lumyou can't short arc Al. Spray only. MM350P is incredibly forgiving on Al. It welds incredibly well.
Reply:The mixes I was reading about were very very small percentages <2%of the other gases. The majority was argon, then some helium. I dont need anymore heat, I am just lookin for a was to make the process less sensitive to torch angle and travel speed. I gotta get into some werid spots and I end up with alot of spatter here and there. Probably just need more practice
Reply:Ummm, DesertRider33, using a helium blend gas usually requires MORE volts than a non-helium gas.  Around 6 volts more.  And that higher voltage is part of the reason why a weld done with a helium mix is 'hotter' (the heat transfer of the helium itself is another part of why it is hotter).If your machine can supply enough voltage, using a helium-argon mix on aluminum will make for a hotter weld than plain argon.
Reply:The way I understand it, an arc in pure helium would be around 17 volts.  With pure argon, its 12 to 14.  Helium rises, not good for welding flat.  It takes a lot more but the way  I read it, it will get more heat out of the same machine.  They use blends because of the weight of the argon.DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:I stand corrected.  Thanks guys.  I only use argon to weld aluminum, mig or tig.  I don't really see a need for using another gas besides argon to mig aluminum.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op