Another mig ? Open root

admin

Root fine, 3/8 mild steel, .035 wire flat & horizontal position 19.4v temp for root. Hot pass 20v, filler same cap same, bend test face breaks all way down to root, hot pass not even tied in. Instructor doesn't know bout mig so I'm flyin in the dark here. Never had trouble tying anything in? I move fast little circles?
Reply:seems cold, pictures would help a lot
Reply:At those settings you have to ensure your arc is stricking the parent material and not up on top of the puddle. Lack of fusion is easy to acheive while short arc welding.
Reply:pulsed spray transfer would do it. Try turning up the heat and feed speed and moving faster to stay just in front of your puddle
Reply:Is there a reason you have to be in short circuit for the fill passes?  If not, run that up to ~350IPM and 25v (for a starting point)Actually might have jumped a step there, what gas mix are you using?Have we all gone mad?
Reply:Deleted - I explained a 3G Open Root.Not sure what OP means by "Horizontal".1G?2G?It would be nice if you guys in school used the correct terminology.Last edited by Black Wolf; 07-21-2011 at 11:32 PM.Later,Jason
Reply:i attached some pics, from my fillet welds with gmawfirst one is 2g cap temp was about 20v, ipm 4second was an osha safety hazardthird 3g cap uphill temp lower at 18.5 v ipm 2.54th was either 1 or 2g root temp 20v, ipm 4in response to snoborder gas mix is 25/75pulse spray transfer? hate to sound ignorant but how is that different from short arc? i get the pulse, but how would you set that up on the machine and would you need a special power source? we have miller dimension 302 combo post a pic of it on monday.twin thats why i'm frustrated cause i hesitate when i strike my bevel walls with filler wire and they appear to tie in same with cap, use my 10-15 angle degree, push my puddle at about 10-20 degree. tried slowing down adjusting temp, ipm's. clean root with wire wheel, grind hot pass, grind filler, no problems until i grind cap then i can see where all three of cap beads didnt tie in to each other nor top of bevel? Naturally i assume its a heat problem, 20v ipm 4 is as hot as i have gone, go hotter on monday see what happens. instructor started me out at 150 temp around 17v's, so i assumed that was a starting point but apparently he was way off?black wolf i will check out your 3g post, and i don't know what op is either?will post some open root pics on monday 2g. Attached Images
Reply:cut the segment in half polish it and etch it and post a picture please ?I forgot how to change this.
Reply:Think 2nd pic is wrong school.  Plumbing school for plumbers crackTiger Sales:  AHP Distributor    www.tigersalesco.comAHP200x; AHP 160ST; MM350P,  Spoolmatic 30A; Everlast PowerTig 185; Thermal Dynamics 60i plasma.  For Sale:  Cobra Mig 250 w/ Push-pull gun.  Lincoln Wirematic 250
Reply:Think 2nd pic is wrong school. Plumbing school for plumbers crack +1    hahah lol
Reply:Picts can some times look worse than they are. Not sure if thats the case here or not. The 1st and last picts look to lumpy for my taste. The beads look piled up in the center and not that well tied in on the sides.  Pict #3 is usless because of how blurry it is. The unfinished section that wasn't capped with the 3rd bead on pict one is an exception. The way that second bead looks smooth where it meets the 1st bead and the upper plate is more what I'd be looking for myself. A nice well laid multiple bead should almost look like a nice smooth triangle when done, not a washboard like these do. The settings seem close to about what I could make work, so I'd guess it's more your tecnique, stickout or speed of travel thats an issue. It'd be easier if I saw you run it to make a call.Personally I can't weld that well doing circles. I can do it to demonstrate it for students, but I make better welds doing a C or Z type movement or a straight stringer. I'm watching for the puddle to catch up to the arc as I swing from side to side. As soon as the puddle catches up to the arc, I'm quickly swinging to the other side and pausing just slightly for the puddle to catch up again. All this movement is usually less than a 1/16" or 1/8" max left and right of center. Doing so I usually lay a flatter bead thats tied in at the sides well. I also tend to weld somewhat slower than many do when I weld, especially at lower settings and my "weave" is signifigantly tighter, usually moving forward no more than 2 to 3x the wire size.Take a minute to add your location to your User CP so we know where you are at. If you were near me, I'd try and set up some time to give you a hand with this..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:What you described sounds like cold lap.  This happens when your arc is directed at one plate and doesn't carry over to both plates or when the arc is not directed at the plates rather it is too much on the weld bead (like in the middle or back of weld puddle).  If you were to z back and both going from one plate to the other at the front of the weld puddle you would notice a big difference.
Reply:Thanks for the tips! I been so caught up with temp and wire speed, haven't considered it might be my technique. I will focus more on technique and post some more pics tom.