Mig Welding, Inductance

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This is how I understand inductance: Higher inductance helps flatten the bead, basically helps make the puddle/bead wetter so it lays down better. Lower inductance has basically the opposite effect, which leads to a higher bead profile and more slag.   Is this correct? Also, how would using different gas effect inductance, such as straight co2 compared to 75/25, would changing the inductance have the same effect with the different gas? I have some more questions about spray arc, but I want to search around and do some reading on it , that is if I can find anything on it.  I dont know the first thing about spray arc... I think I have ran spray arc before with my old miller 252 and didnt realize what I was actually doing..  Is spray arc when your running hot enough that the wire pretty much sprays right into the puddle and lays down real flat and gray looking? Thanks.Last edited by brucer; 02-05-2013 at 11:33 PM.tackleexperts.comwww.necessityjigs.comhttps://www.facebook.com/groups/mach...dingequipment/
Reply:Inductance with MIG slows the power supply's ability to react to the short circuit. A CV welding machine wants to go to max amps NOW when the wire is shorted. With inductance it takes more time (in milliseconds) to get to max amps.With no inductance a small ball is formed & the wire is pinched off (can't carry the current). With some inductance a larger ball is formed before the pinch point is reached and the crater is pushed a bit deeper.I don't think inductance helps with 75ar/25Co2, although most people don't use C25 to put the amount of wire to the task than it can so it may wet the surface a bit more at lower settings and help the looks at the toes some. With Co2, inductance allows for higher settings that go unstable without it. With Co2 at lower settings it seems the puddle spreads better if you have your settings right for the material section.To power supply makers this is referred to as a flat V/A curve for no inductance and a slightly drooping V/A curve for inductance. Historically the flat curve V/A machines were the Miller & Hobart (pre-merger) type machines and the Union Carbide/Linde/Esab, Lincoln and T/A for added inductance. If you've been around both types you can quickly tell which is which by the sound but with the MIG in capable hands it's hard or impossible to tell the difference by eyeballing.There is a sh!t ton of stuff out there on axial spray (spray arc), so you'll be searching & reading for a while.Good luckMattLast edited by Matt_Maguire; 02-06-2013 at 08:54 AM.
Reply:As the CO² content (%) in your shielding gas reduces, you'll want  to increase the inductance to help with puddle wet out. You'll want to run more inductance with C25 then you would with C0².Your inductance control is for short circuit transfer. For spray I'd start out with the inductance dial on the low side. To much inductance can lead to poor arc starts.As you increase the inductance you should notice that the short circuit transfer arc becomes softer.ESAB Migmaster 250 Hobart Ironman 230Multimatic 215TWECO Fabricator 181i & 211iHH125EZ - nice little fluxcore only unitMaxstar 150 STH - very nice
Reply:I knew what inductance is (college good for something) but I never knew what it had to do with MIG welding. Just did some reading.. pretty interesting.
Reply:Picture will help too.. less indutance is on the CO2 setting...http://www.scottgrossstore.com/catal...0558002888.jpgEsab/Lorch ET-220iEsab 160i caddyThermal LM-200 Lincoln feedersThermal Pee-Wee 85sThermal 60i- 3phase /RPC powered (Beast)Thermal Drag-gun 35CINE 1500 Klutch 140i
Reply:All I know about inductance settings in my current MIG setup is that it has a HIGH and LOW inductance conectors for the ground clamp. Provided we are talking about a 3ph 400 unit... it has been set in LOW inductance from the very beggining. I never dare to change it as I understood by the manual that the HIGH setting is meant for thick material, which given the machine, it is by no means the 6mm (at most) that I have been welding with it.Just for kicks I will give it a try nex time. We run it with C15 all the time.Mikel
Reply:Originally Posted by Brand XPicture will help too.. less indutance is on the CO2 setting...http://www.scottgrossstore.com/catal...0558002888.jpg
Reply:Originally Posted by DanAs the CO² content (%) in your shielding gas reduces, you'll want  to increase the inductance to help with puddle wet out. You'll want to run more inductance with C25 then you would with C0².Your inductance control is for short circuit transfer. For spray I'd start out with the inductance dial on the low side. To much inductance can lead to poor arc starts.As you increase the inductance you should notice that the short circuit transfer arc becomes softer.
Reply:Originally Posted by DanMy inductance control doesn't look like that.
Reply:Originally Posted by brucerWould I be better off to go to an 80/20 mix if I want to mess with spray arc in the future?What would you recommend?