mig uphill

admin

I'm trying to get better at mig welding in my farm shop after years of using only stick. My question is this, if someone is kind enough to educate me. I was in a fabrication shop the other day and a welder was welding the tongue on a trailer vertical up (something I have trouble doing). His method was to basically use a series of spot welds moving in increments of about a sixteenth of an inch. He was using 75 - 25 gas and a miller 251 welder. Is this a method anybody else out there would use?
Reply:when i run mig vertical, i usually go side to side and watch the puddle.
Reply:ABSOLUTELY NOT! that is not how you weld vertically. PERIOD! Shoot, that's not even really welding. welding vert mig isn't that much different than doing it with stick. The only difference being that your hand doesn't change possition in relations of it's distance from the work peice as it moves up the weld. I do a z pattern up stoping on the sides and going quick accross the middle.There are no problems. There are only solutions. It's your duty to determine the right one.Hobart Handler 210Airco 225 Amp MSM Stinger
Reply:Jody on Weldingtipsandtricks.com has a good vid on uphill mig.MM252 30AMaxstar 150STrailblazer 301gDialarc 2509100XX Hypertherm PM 30                      Milwaukee4 BaldorsKohlswa shop anvilScott truck anvilStonewell farrier rig
Reply:For fillet welds (3F), I was taught an upward-pointing arrow pattern for the root. The "arrow point" digs into the root which "waving the gun across back and forth" in a "weave" just doesn't do. You need a constant stickout. once you get the root, you no longer have a sharp corner and it becomes like you do a groove weldFor the rest (if needed) "weave" is like a ladder. The drawing is kind of sloppy but I hope you get the idea. Easier to do than to draw.What you end up with resembles my avitar and will pass Xray inspectionLast edited by wirehead; 06-26-2013 at 02:12 PM.XMT304 (school)SP125+ (home)HF 4x6 BandsawGood judgement comes from experience and much of that comes from bad judgement.
Reply:Those series of tacks he made are just that, a series of cold welds that will be prone to failure, they look good but are not suitable for anything that is going to support any kind of load.
Reply:Originally Posted by ironmangqThose series of tacks he made are just that, a series of cold welds that will be prone to failure, they look good but are not suitable for anything that is going to support any kind of load.
Reply:I hope the guy doing the welding on the trailer tongue has good liability insurance. I go from side to side in a slight arc or reverse V pattern. I Hold the corners for a good two seconds if it's a large weld joint. Don't linger in the middle it will fill up.  This is how I do vertical up and is the process to pass the structural weld test in my state.  It has to pass the big bend test to pass the certification.
Reply:You mean tacks like this guy ...... start about 1:23 min. of the way in on the videoLast edited by assassin_works; 06-27-2013 at 12:45 AM.Lincoln Power Arc 4000 Thermal Arc Fabricator 252 iThermal arc 186Thermal Arc 26 tigTweeko 200 amp spool gunHobart AirForce 400WP-17V-12R
Reply:That's an odd method, no?TA Arcmaster 300CM3XMT 304S22P12 suitcase feederX-Treme 12VSOptima pulserTA161SMaxstar 150STLHypertherm PM45OP setupStihl 020AVP, 039, 066 Magnum
Reply:Originally Posted by Drf255That's an odd method, no?
Reply:Not a proper method for a trailer tongue, maybe for welding body panels in but definitely no good for anything structural
Reply:During my Carman apprenticeship they sent us to the local community college for welding.There they taught us when going up  to weave, holding on the outsides and faster across the middle.Fast forward 2 years we had a Install stiffing patches on covered hopper cars almost 13' of weld around each patch. The company we where repairing these cars for did not want this weaved. So the RR brings in there welding instructors and we learn how to run a bead straight up. I do both now depending on application.I have noticed in the shop must of the struggles guys had can be attributed to welder settings.Turn it down your running to hotAlso I think its easiest to learn to weave 1st then go on to stringersSammy
Reply:Thanks for everyone who sent a reponse. Your help was greatly appreciated.
Reply:Yea that is a wack form of pulse welding with the mig,  depending on the wire you are running the heat and speed are the critical points to dial in then you can breath a bit and not worry so much about the weld falling out.  when I give a 3G plate test for MIG I usually have them set the machine to their idea of what works and most end up going too hot.  17ish volts and under 240 on the wire speed. then you can take your time a little bit.  I would weave like you would with 7018 verticle, just smooth minor changes and stay consistant. make sure the puddle is getting full fusion.  95% of my students FAIL the verticle up MIG solid wire test cause they dont focus the direct shorting of the circut on the the base metal.  You cant stay on top a puddle and keep pushing it up. It will not carry enough heat to make a real difference.Keep Welding!-J