ground question

admin

Just a question for you guys, I had a customer bring in a PTO shaft to be built up and machined back to spec for his bearing. No problem, I do these often. I fired up the Lincoln 255 mig and started welding but I was getting a lot of porosity from the cast steel it was made form so I ground out the bad overlay and fired up the XMT304 and burned it in with 6011, the shaft turned out great. The question and mystery to me comes in when another customer comes in an hour or so later and needs a new end fabed and welded on his hyd cylinder. I was going to weld it on with my thermal arc hefty II suitcase (powered by the XMT304) with ultracore 75 dual shield, I couldn’t get the machine to work so I started checking things and the ground wasn’t hooked to my fab table. The only ground on he table was for the Lincoln mig. Sorry for the rambling but the question is why did the XMT work to weld the shaft earlier with no ground on the table other than the one from my Lincoln mig? Or I might just be going crazy!LarryMiller XMT 304 CC/CVSyncrowave 180 SDLincoln PowerMig 255XTTermalDynamics 52Lincoln 305GComlpete machine shop to back it up
Reply:I saw that at school twice. Buddy next me was having a horrible time getting 7018 to burn for our fill, BUT his 6010 root laid right in...Upon my observation, I said " dude, wheres yer ground", It was dangling from its holder, not attached to the table. Instructor laughed, and said he's seen that at least 3x a year for the last 10yrs he's been teaching...He wouldnt tell us why it happened, we were supposed to figure it out on our own...never did either...Lincoln Power MIG 210 MP ( boat anchor )Lincoln Weld-Pac 100 HDHobart IronMan 230Cutmaster 42Jackson NexGenSumner Ultra ClampsDWM120
Reply:electricity will take the lest path of resistance, so I would be thinking that your xmt ground cable must of been touch something to make a circuit,