roll'n 6" Sch 80

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6" Sch. 80,  1/16 land, 1/8 root opening ER70S-6 hard wire all the way in 1G position. Root:  1 continuous pass in  3.5 minutes (approximately 4.82”/minute)  welding in the 2:00 to 3:00 o’clock position downhill.   RMD mode with a WFS of 150. Fill Pass: 1 continuous pass in 3:41 in ProPulse mode at a WFS of 230 welding uphill at around the 1:00 o’clock position. Cap Pass: 1 continuous pass in 4:39 in ProPulse mode at a WFS of 210 welding uphill at around the 1:00 o’clock position. Total Passes: 3 Total arc on time:  Just under 12 minutes
Reply:What machine did you use? I use an Axcess 450, but I don't have RMD. Always wanted to try it though.IAMAW Local 330Airco 300 AC/DC HeliwelderAirco Dip-Pak 200 with Profax spool gunPowr-Kraft AC225Everlast PowerArc 200stBuffalo Forge No.21 drill pressSpeedglas 9100xxAirco, Oxweld, Purox, Victor torchesLincoln Ranger 8
Reply:PipePro 450 RFC
Reply:Looks good
Reply:While it does look pretty good I see one thing I can do to improve on the ID root profile.   If you look in that first picture you can see at 5 and 7 o'clock where two of the tacks were.   The reason they stick up was because I made them in the 1 o'clock position and the weld tends to drop thru more when welding up high in that area.  My thinking is that if I move down more toward the 2:30 to 3:00 o'clock position my tacks will be flatter and thus blend in better to the finished root.   I'd really like to see if I could get one where it's not so apparent where the tacks were.Should have a QC guy coming out the first part of the week to witness one being run and fill out an official PQR.   Then it will be sent out for testing.   Hopefully it won't be long until I have a qualified WPS to Section IX and I can start knocking out some production work.Last edited by HT2-4956; 03-15-2014 at 09:56 AM.
Reply:Very nice.The spot in pic 1 at the top right looks as though it may not have made it all the way through.It may just be the lighting, though.I was always a little nervous with the 1/8 gap on the MIG roots. I preferred 3/16, but then you had to turn down the machine and travel slower.but that way I could watch the puddle melt out the edges every time.I was never really good at getting the "feel" of it, had to see it.Interesting to see your times.Even though only on 6", you couldn't have done that on a machine without a respectable duty cycle.Good for guys to know who wonder when they might need more than 30% at 140 or 150.By the way, what were you running the various passes at?
Reply:geezer,I see what you're talking about at the top right in picture one.   I'll have to take a closer look at it Monday morning to see for sure.   From its position it looks like where I was coming off a tack and it could be I missed getting a small spot.   I'd have to say that appears to be another good reason for doing the tacks down closer to 3 o'clock so that they come out flatter and are easier to tie in better when welding over them.   As far as what settings I was running the various passes at well, this is where it gets confusing.   This PipePro 450 is not a MIG machine in the conventional sense like most folks understand them to be.   For one thing it's working in CC rather than CV mode.   The root pass was done with an improved on short circuiting transfer mode called RMD (regulated metal deposit) that's controlled by the machines software.   I don't get to make a voltage setting like you do with a regular MIG machine.   Instead I set the machine for what wire size I'm using and it takes over from there setting the optimum voltage based on the wire feed speed I set.  Then there's two other  fine adjustments called "Trim" and "Arc Control" you can use to influence the arc characteristics  (mainly arc length and width of the arc cone) that in turn influence the shape of your bead.    The fill and cap were done in a pulsed spray mode.   And again here the machines software is taking care of the voltage setting and I only have to set the WFS and fine tune things with the Trim and Arc Control functions.
Reply:Now, that is cool.I would be afraid to use a machine smarter than I am....of course, my hammer gives me a good run for my money, in that department.Whatever it does, the Pipe-Pro seems to do it well.Coming off of tacks:That is another reason I liked using a 3/16 gap. It was easier to make sure, when feathering my tacks down to paper thin, to make sure I included the land in the feather also.Most guys were good enough to use 1/8 gap, but I needed the extra reassurance...but I always loved Migging the root.Good welding!
Reply:You sure RMD and ProPulse are CC mode?  I thought they were a varation on traditional short-arc and pulse spray, respectively.
Reply:geezer,I understand what you're talking about when you talk about prefering a 3/16 root opening when using the old school "short circuiting mode"  of putting a GMAW hard wire root in pipe.   This new inverter based wave form controlled wire welding that Miller has developed the technology for has caused me to question just about everything I thought I knew about the process.   I'm shipping a pretty good quantity of ethanol aboard right now so I probably shouldn't be typing any way but....Here's a picture of the top section of a root in apiece of 8" Sch. 40 in the 6G position using the machines RMD mode.   .035 wire with 0 land (knife edge) and a 1/8 root opening, down hill.  It got flatter as I got towards the bottom (but just as even) and was pretty much flush at 6 o'clock (with just a spot of 1/32 suck back where I joined up on a tack).  You just can't push it up in there like you can with 6010 because the machine is controlling the arc length and won't let you physically do it.
Reply:Originally Posted by Fred sYou sure RMD and ProPulse are CC mode?  I thought they were a variation on traditional short-arc and pulse spray, respectively.
Reply:Sure makes a pretty root.On another note...I would like to hire whoever keeps your shop clean to come clean my house.Oops! I hope my wife is not a member of the forum.
Reply:That RMD is the cat's meow, I like to use it when they put me in one of the bays that has the new Pipeworx 400 machines, otherwise I'm stuck with nasty old short arc.
Reply:TimmyTIG,I'd certainly like to hear more about what you're using the Pipeworx 400 to weld on and how you're going about it.   As I understand it the Pipeworx 400 is an updated version of the PipePro 450 (which they've discontinued making).   The major improvement being that they've simplified the user interface so that it's not as complicated / confusing to set up.What's the mid-point and range of your "trim" and "arc control" settings?    My experience is that RMD put's down a thicker root pass than regular short arc and is there for easier to put the first fill pass on (at considerably higher heat and speeds) with out having to worry about burning thru.