mig welding question

Tue, 31 Aug 2021 15:34:05 GMT

go to see Welding Machine for mig question

I currently just started a job at a place that manufactured dump trailers out of mild steel, hardox, and aluminum.  Any ways the heat ranges they weld with are way to hot than I was taught to use. for 10 gauge mild steel they are welding with 34 volts and 450 wirespeed. my flat welds look fine if i move a little faster but not as good as some of the other workers. also I cannot get my vertical down welds and over head welds to look as thin and consistent and the other peoples. anyways i was wondering if there is some kind of technique to doing this fast paced mig welding.
Reply:You're definately in spray transfer at those settings.  Spray is only suitable for flat/horizontal position, as the puddle is too liquid to control acceptably out of position.  I'm surprised anybody is able to make a passable weld vertical or overhead with those settings.  My guess is they're turning it back down into short circuit range for the out of position joints and you're just not aware of the change.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:yea  i didnt know what it was because were using 25/75 mix gas
Reply:You are talking about solid wire right?no one knows what it is if they are using 34v 450ipm with c25 gas. I'm guessing they are still using .035 wire? trying to use to many volts to compensate for the c25? sigh...production work is like this sometimes...
Reply:Nothing about those settings seems right.The V/WFS would indicate a spray transfer, however the gas mix would force you into a globular transfer mode which you wouldn't want. (excessive spatter)For out of position, I don't know how any of the welders are controlling a spray transfer without pulse.  Even then, the gas is wrong.What machines are you running?BTW: If it's C25 you're running, it's generally referred to as 75/25 with the 25% being CO2.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:That setting dont even compute (to me) as a decent spray transfer setting. It's about 9 volts to high for .035 wire. That setting with .045 wire would probably blow through 10gauge just tacking pieces up. My best guess is this. Whoever came up with the procedure has no idea what they are doing but they want to produce products faster so they just turned the welders up and figured it would be ok. I've seen some hinky **** in my days as a production welder. like pegging the V and WFS on a MM250 with .035 wire, c25 gas and welding overhead on 12 gauge. They should be around 19v 260ipm w/ c25 imho.
Reply:I've seen those silly long arc lengths (more like 36-40V) with 1/16" wire on junk plate. The transfer is globular but very low spatter and the beads very narrow. The process makes at least double the smoke and fumes that real axial spray does, so there's a lot of material just getting burned up by the arc.There also has to be a crap ton of oxidation in the weld with all that active gas, and if tested prolly wouldn't muster very good properties.Also of the several shops I knew doing this (building ag stuff and off-road sub assemblies) in the late 80's/early 90's none remain...Matt
Reply:sorry i meant 75/25 mix gas and solid core .045 wire. and as for what process they are trying to achieve i have no idea. As long as im gettin pay check im fine with welding the way they want im just looking to see if there is a way to make it a little nicer looking.
Reply:solid core= solid wire? they need to switch gases in my opinion. You can spray overhead easier than most people think. vertical is another story....
Reply:I worked at a dump trailer place also; before getting laid off. I first started out there right out of school and noticed the same thing. The machines were older cranks style miller welders; which the guys always had at full crank around 32-34 volts and sometimes full crank on the wire speed. Also using 75/25. After using it for a while you can actually weld all positions that way. You just have to move super fast. Anything done vertical was vertical down. Lots of guys had cold lap.  But being production work and everything being about getting it done fast that was the way our shop worked.