some welding problems I have

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Hello, I am a trainer in a technical school for plummers and we often use welding for some works.I have not a lot of experience about welding and I would like you tell me your opinion for some problems which I have.I use a MIG  machine and I create very bad beads, as it seemed in the follow pictureThe nippers of the MIG is not at very good condition(see the two pictures below). The spring of the nippers has been replaced by a wire. Could this condition cause problems at bead?Also, I use a stick welding machine and I try to weld pipes but I cause holes very often, like the pictures below. These holes are created even at very low Amper(35 Amper for example)How can I confront these  problems? Sincerely!
Reply:I am fairly new to this too, but is your polarity set correctly?  When switching between flux and the regular wire, if I forget to swap polarity, I get crappy results.
Reply:need more info :like the what machine, type of wire FC or solid ,gas setting stick: what rod ? ac -dc?if your using solid wire you need cover on and gas if FC maybe too hot for thin metalidealarc 250/250 ac-dc tigidealarc 250/250 ac-dc tig #2 used for sticklincoln sp100hh125dual arbor grinder polisher30 yrs of hand tools52 pitch blocks 6p-26prake gauge -pitch gaugeG&D prop repair 918-207-6938Hulbert,okla 74441
Reply:On the mig welds, I don't see any slag on the beads so I assume you're using solid wire and gas, rather than fluxcore.   If that's the case, the problem is you're not getting shielding gas coverage.   You need to put a gas nozzle on that torch so the gas can flow over the weld, that's why there's porosity all through the welds.   Set your gas regulator to 15-20 cfh and test to make sure that there's gas flowing out the ports in the diffuser when you pull the trigger.Also set your polarity with the torch on the positive terminal for solid wire and gas.  For fluxcore self shield wire (no gas), the torch connects on the negative terminal.On the stick welds, thin, small diameter galvanized pipe butt welds are not what you want to practice on to learn stick.  Run beads on flat plate instead untill you get the hang of watching the puddle and moving it along.  If you're running 6010 or 6011, you need to whip and pause it, or run small circles with it.  Those rods dont just drag straight along like the others.   Whip forward to dig, pause back to fill, repeat.  All the others you can move in a straight line forward without whipping.Last edited by DesertRider33; 12-08-2009 at 04:41 PM.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:What is the "nippers" you are referring to?? Anyway that's solid wire sticking out of the tip and gas diffusor so I assume you're using gas. What I don't see, and maybe you removed it to show us that coil of wire, where is the gas nozzle? Those beads look like little to no gas coverage. You are running with a gas nozzle and a good seal around the back side of the gas nozzle aren't you? Thos slots cut in the ribbed area where the nozzle would slip on look like you could easily get a venturi thing going there.
Reply:How are the other students doing with their welds? Matter of fact, how is good is the instructor at welding? This may be a case of the dumb leading the blind.
Reply:Go watch someone who knows how to use a MIG...think it will become more clear.  I'm new too...but....think you are missing some main principles about welding with MIG.  Ten minutes with a real welder should solve your current problem.
Reply:Originally Posted by transitHow are the other students doing with their welds? Matter of fact, how is good is the instructor at welding? This may be a case of the dumb leading the blind.
Reply:Originally Posted by DesertRider33If you re-read his post, HE's the instructor and it's not a welding class.  It sounds like he intends to teach welding, after he learns how himself.
Reply:If you want to teach welding to your class, it would probably be a good idea for you to take a class on welding. It's not some thing you pick up over night. There's a reason that tech schools and colleges have two year courses for welding. Sure there are shorter programs out there to teach people a few basics. But if you want to teach your students the basics, you're going to want to take one of the serious courses for yourself. That way you'll be more qualified to help your students with any technical difficulties, and you'll be teaching them the right way to weld, not the way you hope might be right. If you're going to be training people how to do something, the end result of which could jepordize some ones safety, then you're partly responsible for them and their work. Nothing against being self taught, but I've seen too many people that were self taught, or just got some basic training and thought that they could teach others, when in fact they only knew enough themselve to be dangerous. For example check this link.http://www.weldingtipsandtricks.com/...t-to-weld.htmlSure he looks professional, and sounds professional, but virtually every thing he says and does is WRONG. I would hate for that to be you. Take a class, teach your students right.
Reply:Originally Posted by transitI forgot that part. Instructor? Ho boy! He uses strange terms for the mig gun and his equipment looks questionable. I would think that an instructor would have a few years experience in the subject he’s teaching. At best, he’ll be one page ahead of his students. There is no info in his profile, could he be British? Strange, plumber welding? British?
Reply:Grimm1, “looks and sounds professional”?  I don’t think so, not even a close country mile. This thing? Spot-weld? Up and down? Cress. Trim the feed, anyone hungry? There are tons of videos better made. Well I have to say, he did manage to plug the unit in, make some sparks and melt some wire.
Reply:Well... to an actual professional he's clearly a joke. But to a beggining self taught first timer this guy might seem like he knows what he's talking about. He obviously thought he did.
Reply:Agreed. Hopefully anyone coming across his video is also looking at other online welding videos and may notice a bit of a difference.Did you read the caption above the window? “Thanks so much for this video, I only watched it once and I am already making welds that break easily”. Looking at things closer, we’ve been had. I think the point is not to use training videos, take a course in welding.Last edited by transit; 12-09-2009 at 10:49 PM.