4f gmaw. Help

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I started over head mig today. I'm having a hard time with the crowns of my welds sagging. If I speed up I can keep the crown from sagging but the weld gets thin with a very high crown.The metal is 3/16 welder is a MM350 19 volts 270 wire speed. I have even tryed 18 volts and all the way down to 250 wire speed with no luck.No pics. But any advise would be helpful
Reply:Joint or bead on flat plate? Beads on flat plate are always on the tall side.To me if you can read the puddle, overhead is easy. If you are doing any sort of oscillation or motion, chances are you are spending too much time in the middle. I know a lot of guys say to simply run it like flat, but personally that description never worked well for me. I keep a super tight arc and run a small C motion so I can concentrate on each edge as I move forward moving the puddle where I want it to go as needed.Picts would help me pick up some of what you are doing wrong..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:I tryed it again at home with my hh140 maxed out. Same thing. I have tryed a whip and cursive e. I am running about 1/4 stick out. Maybe my torch angle is bad???? Loading picsHh140 030 wire voltage set on 5 wire speed set on 45.  3/16 steel
Reply:First pass on a three pass t joint
Reply:Second pass. Humped up but not sagging as bad as I did at school with the MM350
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Reply:Final pass
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Reply:One problem I see with those welds is that the HH140 really doesn't have the balls to run 3/16" steel even if the manual gives you settings for it. Under real world conditions it tops out at 1/8". because of this your welds will always be tall and cold.The 1st bead looks the best of all of them. #2 being a close second. Both look a bit cold, but that's no surprise with that machine. The 1st one I'd have liked to see your motions a bit tighter. The 2nd one The motions are tighter, but I think you went a bit too slow so the material piled up more. Something in between the two would be a better choice. I'd keep the motions small and fast and watch the edges to see then wet in well and fly to the 2nd side and do the same thing.Last 3 picts it doesn't look like you are concentrating on the toes as you watch the puddle. All of them look tall and cold. In the pict with the penny, the bottom bead on the far right, the bottom washed in much better than the rest of the beads, so it certainly could be better than you did. I'm also not seeing you get the two beads to meet in the center well. Either you 1st bead was too large, or the 2nd ones were too small, or a combination of both. Again the low output of that machine is fighting you. With a bigger machine, I'd say crank up the heat more to flatten out your beads. It seems counter intuitive, but often more heat run faster will help with overhead. T joints are "easy" since you don't have to worry about suck back like you do when you run open root bevel buts if the heat is a bit too high. I'd watch the edge of the puddle for it to wet out, then fly to the other side and watch that edge..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:Thanks dsw!  So with the MM350 and 035 wire I use at school, should I try bumping it up to 21 volts and maybe 275 wire speed? Because I was getting similar results at 19 volts as I am with the 140 hobart.
Reply:It's been a bit since I ran overhead at the tech school. With the new night instructor most of the guys choose to change processes 1/2 way thru the class, rather than going all the way thru mig to overhead. I don't think this year I've had any one who actually wanted to go all the way thru past vertical in mig. Honestly I'd like to see guys get at least thru vertical and try overhead, because I think it gets them to actually learn to read the puddle, but most are more interested in trying each process this term than they are on dedicating themselves to really "learning" something they can use as a trade. Nothing wrong with that since I can remember being at that point at one time in the past.I know running .035 wire and 92/8 argon CO2 I was a bit too hot on my root passes running 19 to 19.5 on the 3/8" open root bevel joints with 3/32" gap. 1/8" land and about as short a stick out as I could possibly run, when I was running practice coupons years ago. I got great penetration, but I got a some suck back on the beads. However I seem to remember running that voltage no problem, possibly higher on the T joints, and I'm pretty sure I cranked the voltage up once I got the root burned in the way I wanted on those bevel joints. I'd have to set up and run some to get a feel on where I'd want to have my settings, but the 18-21V range sounds about right without going back to my notes. 21V I'd probably be up around 375 with .035 wire off the top of my head, maybe around 325 IPM if I was down around 20V. I know some of the feeders at the tech school don't set the same as others do, so a lot of times I'm adjusting the wire speed more by eye and ear than I am by any set numbers running test pieces on scrap..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:Thanks again for the input man! I will give it another shot tomorrow and post pics .
Reply:Sorry no pics dsw. But I got it! I was welding until the instructor was about to leave but I finally got a couple ok overhead ts!I ended up cranking the MM350 up to 21 and 300ipm and moved faster with very little stick out.  I dont know how to explain it, but it looked like i was running dual sheild. It was very hot! But thats what it took for me to get them pushed in.Turns out a little bit of sag at the crown is ok but not a lot. They were more concerned with the toes tying in and proper bead overlap. I got a 95....maybe a pitty grade because I would have gave me a B, but what ever.Thanks again for all the tips!
Reply:Congrats!  Yeah it often seems counter intuitive to go hotter overhead to reduce sag, but it works if you understand what you have to do different and have learned to read the puddle. If nothing else you can always back off a bit to cool the puddle down by increasing your stick out. Too many people are scared of vertical and overhead, and run cold. That just reinforces their fears as things get ugly. Once you truly can read the puddle, these are easy. I'd rather run vertical than flat honestly. I enjoy the challenge of making really nice vertical beads..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:Lol I need to work on 3g with mig. But for me 3g was always tougher than 4g. Even with stick
Reply:That may explain part of the issues I see with your overhead welds. You may not quite have reading the puddle down quite yet. The demo I do with most students who are starting out on vertical is to do a super exaggerated weave. I tell the student to pay very close attention to the ends before I shift up and start back across. I want the to watch as I pause and wait until the puddle catches up to the arc, then I start back across to the other side and repeat the process. With mig there is also often a distinct sound that you hear when the puddle catches up to the arc as you pause. The bead itself looks very ugly many times, but the idea is to separate each pause and wait so the student can actually catch me doing it. then I run the same drill, but make the weave smaller and faster. After 1 or 2 runs I actually go ahead and run the bead like I normally will with no weave at all. I'm still pausing at each side as I do a C shape for example, and cross the middle fast but my motions are so small and done so fast that it's hardly noticeable many times.Post up your attempts at vertical so I can see them and we can go from there. I'm pretty sure I have an idea where your issues are, but I need to see them to be sure..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:Ok. I'm starting FCAW next week but I will see if I can bring some metal home to try with the HH.