My Mig beads and varied IPM settings

admin

I'm welding with a Millermatic 252. I've welded a couple of steel tabs on the side of this 1/4" inch thick steel tubing. They were originally vertical, I pounded them over to get a general strength test. I'm using .035 wire and C25 gas.Recommended settings for this are 21/375.  I deliberately set the wire speed 50 below, and 50 above the recommended. One thing I don't get as a beginning Mig welder, is the higher IPM setting are supposed to produce higher currents, why does it produce colder looking welds ? And the weld at the setting 50 lower than the recommended IPM looks better with a better penetration appearance. Also, hammering them over seems to show equal stength. Maybe the pro's can shed some light on this.
Reply:You're neglecting to figure in the third variable...How fast did you move the welding gun?  If you move the gun at the same speed, while using a higher wire feed speed, your weld will not have as good a finished appearance(all other things being equal)Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:The major difference is that using 75Ar/25CO2 gas , at 325ipm/ 21 volts you're still within the range of "short circuit transfer." [ame]http://www.youtube.com/watch?v=i_edwUW92u0&feature=relmfu[/ame]In contrast at 425ipm/21 V you're into the range of the erratic, unstable "globular transfer." Note:This is a high speed video.[ame]http://www.youtube.com/watch?v=-_4-h0Ndpfs&feature=relmfu[/ame]Furthermore at 425 IPM and 21 volts gives you insufficient arc length leading to erratic arc operation and lack of cleaning action of the base metal. At 425 IPM you want to be using closer to 25, maybe 26 volts.
Reply:They both really dont look that well, and if you hit them at the base instead of the weak points I would bet they both would have broke. Just being honest I hate being bi-polar it's awsomeMy Heroes Have Always Been Cowboys
Reply:Thanks for the informative replies. As good as going to Mig school. Normally I always use the recommended settings, then maybe tweak it a little. But since I'm new to Mig, I like experimenting with both extremes. Create a huge mistake, then learn from it.Miller Bobcat 250Syncrowave  200Millermatic 252Spoolmatic 30ASpectrum 625 X-TremeMaxstar 150SVictor O/A torchesDewalt angle grindersWelded on/off for over 40 years.
Reply:By the way, those are interesting videos Joshfroms... Thanks for postingMiller Bobcat 250Syncrowave  200Millermatic 252Spoolmatic 30ASpectrum 625 X-TremeMaxstar 150SVictor O/A torchesDewalt angle grindersWelded on/off for over 40 years.