open back mig Vert-up

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started doing open back verticle up on mig at school. And I have been having some problems with just blowing through the plates. I am using .035 with 100% co2 at 25CFM, 2.75 fpm and I would tell you the rest of the setting but on the machine I am using they have no read out for them which drives me insaine and it works. the plates I am using are 5/8s with 3/32 gap and 1/16 landing. I am running the gun at an upwards angel to try to keep the puddle moving up but I am having to keep my movement pretty slow to get full pentration but its blowing through. I just cant get this one.
Reply:Spent years welding and have never seen anyone use a procedure that called for an open root hard wire GMAW process.Could you ask your instructor for me as to why you are learning this?A more common procedure would be same joint but with backing.
Reply:Originally Posted by violatedpplstarted doing open back verticle up on mig at school. And I have been having some problems with just blowing through the plates. I am using .035 with 100% co2 at 25CFM, 2.75 fpm and I would tell you the rest of the setting but on the machine I am using they have no read out for them which drives me insaine and it works. the plates I am using are 5/8s with 3/32 gap and 1/16 landing. I am running the gun at an upwards angel to try to keep the puddle moving up but I am having to keep my movement pretty slow to get full pentration but its blowing through. I just cant get this one.
Reply:your landing is too small. Try making it the same as your gap.
Reply:Hold your gun close to 90 degrees, move across the gap without pausing and pause breifly at the edges to fill.
Reply:Vert down for a mig root.  The rest of the pass's are weave vert upTrailblazer 302 AirpakDynasty 200 DX  Thermal Dynamics Cutmaster 52 CamoMiller Dailarc 250 OLD But great!!2 Miller 140's w/autoset NEW! Millwauke Cold cut sawsDewalt portabandJd2 notcherPipe beveling machine
Reply:Originally Posted by worldsgreatestwelderSpent years welding and have never seen anyone use a procedure that called for an open root hard wire GMAW process.Could you ask your instructor for me as to why you are learning this?A more common procedure would be same joint but with backing.
Reply:from the reading on the wire feeder I am using I would says its around 2.7 feet per minute. and its just a position that is part of the lesson plan, when I talked to my teacher about it he said he had never used it since he learned it at school. But for me its kinda helping me for my open back stick than I will start on pipe for stick once I get the root passes down on plate. And I have to use vert up to get full penetration. I tired down but it just wouldn't fully pentrate.
Reply:OK, It was a slow day at work, so I tried it....3 times.  Twice with .035 and once with .045 wire.  I have a 3G cert for bare wire, .045 Co2, unlimited thickness.   You asked for .035, so that is what I did.  Open root is odd to me.  When I took the test, I could use a 1/4" X 1" backer.  The wire goes right through the gap. Wire speed 250, Twenty point something volts.Root pass Back side, I stopped twice because it was too hot.  You can see where.Last edited by David R; 01-24-2008 at 08:20 PM.Real world weldin.  When I grow up I want to be a tig weldor.