Mig Test tommorow morning

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I go for a interview and mig test tommorow morning so I practiced doing the test the last 2 nights in school. Teacher says I have nothing to worry about with my welds but was wondering if anyone else had any advice or tips for me when I go in tommorow.Test is 1/4 inch plate vertical down and 1/4 plate horizontal.For my practice test I was using a miller 251 mig set to 21 volts DC and 360 for the wire speed.Vertical down welds(start was a little cold on this one)HorrizontalThanks for any advice.
Reply:I reckon you will be fine just dont choke up on the interview remeber to sell yourself make sure they know how keen you are etc..the only advice i got for ya about the welds is on the vert down if you get a chance try doing stringers for the cap makes it look neater or is it single pass only? and your Horrizontal try just doing i tiny weeave it wet's the toes out but they both look great hopefully you get the job keep us up to date fingers crossed*Edit* your second pic on the horizontal is right onLast edited by Bozzza; 04-28-2010 at 01:26 AM.Cigweld Transmig 265seBoc 140amp StickBoss 200amp AC/DC TIGLincoln Electric Invertec V260-S
Reply:Good luck man! I'm sure you'll do fine.TodHH140HF 4x6 band saw (cut straight right outta the box!)"-Of all the things I've lost... I miss my mind the most."
Reply:Thanks for the good words and I will let everyone know how it goes when I get home!
Reply:Well didn't get it. I want there and put down great welds the guy said and he told me I have amazing hand and eyes for a welder espically at 19 and only have been welding for a few months but because on my practice piece it took me 2 tries to find the right heat setting on their machine he says im not experienced enough and to come back in a month.
Reply:Sorry to hear that. Keep practicing and try again in a month. You'll get there!TodHH140HF 4x6 band saw (cut straight right outta the box!)"-Of all the things I've lost... I miss my mind the most."
Reply:I hope you made your welds significantly smaller than that on your test, those are huge for 1/4 material and short circut MIG.  A weld larger than the thickness of the material is a waste of time and money, something that a potential employer would look at. Your volts are also pretty high, at 21-24 volts you should be getting into a globular transfer, bordering into spray with some gas mixes.  SC is generally run from 16-19 volts.  The wirespeed is also high, but necessary if your going to try and run that many volts.  I like to start around 17 volts and 240 IMP for 1/4" material and adjust as necessary.Last edited by sn0border88; 04-28-2010 at 03:56 PM.Have we all gone mad?
Reply:That sucks. Knowing you needed to adjust the heat setting is important and not all machine are alike. Keep at it and try again. I am sure you will get it next time.Miller DVI2Lincoln Precision Tig 225Thermodynamics Cutmaster 38Everything else needed.
Reply:Sorry to hear that. If your runnig vert down on 1/4 why don't you just run a stringer? Imo that is way to wide of a weave. Also it looks like poresity in your last pic, are you cleaning down to bare metal first before you weld it? I hope things work out for you! Good luckYa gotta spend money to make money!
Reply:Originally Posted by welderShaneSorry to hear that. If your runnig vert down on 1/4 why don't you just run a stringer? Imo that is way to wide of a weave. Also it looks like poresity in your last pic, are you cleaning down to bare metal first before you weld it? I hope things work out for you! Good luck
Reply:Originally Posted by sn0border88I hope you made your welds significantly smaller than that on your test, those are huge for 1/4 material and short circut MIG.  A weld larger than the thickness of the material is a waste of time and money, something that a potential employer would look at. Your volts are also pretty high, at 21-24 volts you should be getting into a globular transfer, bordering into spray with some gas mixes.  SC is generally run from 16-19 volts.  The wirespeed is also high, but necessary if your going to try and run that many volts.  I like to start around 17 volts and 240 IMP for 1/4" material and adjust as necessary.
Reply:We teach our students to set heat on a piece of scrap before welding a test piece. Not all machines behave the same way, so never set heat on an actual workpiece. (We also tape over the numbers on our stick machines so they never rely on numbers to set heat for stick or TIG. That way when they go test on some worn out 8-pack they won't try to do it by unreliable numbers. This works VERY well. )
Reply:Originally Posted by farmallWe teach our students to set heat on a piece of scrap before welding a test piece. Not all machines behave the same way, so never set heat on an actual workpiece. (We also tape over the numbers on our stick machines so they never rely on numbers to set heat for stick or TIG. That way when they go test on some worn out 8-pack they won't try to do it by unreliable numbers. This works VERY well. )
Reply:Originally Posted by BB70ChevelleI original in school had it at those settings on our mm251 and couldn't get it to look right and first thing teacher did was turn the welder up to the setting I listed and my welds got alot better and for the test today I tried at 21 volts first and it wasn't enough heat I had to turn the machine up to 23-24 volt before I could get it to weld right and look good. The supervisor at the company had nothing bad to say about the thickness of my horizontal welds only that they looked great. He didn't have me do any vertical welds while I was there.
Reply:Originally Posted by sn0border88First off, what size wire are you running?  What gas mix?Well, regardless of what your instructor taught you, weaving that vert down is wrong.  A weave like that should be done vert up to ensure good fusion down into the joint.  Did you do that in one pass?  If so, thats way to much metal to lay down at once.  A bead that size trying to fall down on you makes it very hard to get fusion at the root of the joint.  I bet if you did a cut and etch you would see just that.Also your horizontal weld isnt wet out very well, probably because you were pulling it too slow and getting too much buildup.  Pulling will give you better penetration, but if you move to slow the puddle builds up to much and you start to get lack of fusion again.   Also you should work on your starts, start the arc an inch or so infront of where you want to be, and move back to where you want to start.  It helps to heat up the material a little bit and eliminates that cold lap at the start.Lots of guys might tell you that those are great, and honestly while they aren't bad its a stretch to call them good.  It might sound harsh, but no one ever got better hearing "great" as their only feedback.  Run stringers down, weaves up and overall make them smaller.  If I can ill try and run some beads with your settings and see where that gets me.
Reply:Hi BB70Chevelle;He's seen your work with the torch, straight, consistant and steady. Now he may be checking your heart, do you really want it.No offense but any 19 year old seems like a leap of faith for an employer.I agree with the above posts about bead width, and the real issue with that is too much energy is back in the puddle which can lead to poor fusion. Don't worry about that now, you're a student. There are instructors that would "dog" you about the posted welds just to see how far you really could go (they look really, really good for a student).As for settings you can help yourself here, check the airgas link below for some rule of thumb mig settings. Note at the bottom of the page are IPM settings for different wire sizes and burnoff rates for amperage wanted. The chart won't be better than +/- 10% but it is better than nothing and comes from the "total energy" mig equations that are out there. Using a tape measure with a 3 or 5 second pull on the trigger times 20 (for 3sec) or 12 (for 5sec) you have the IPM's. Volt/Amp mig charts are in your materials for class materials. I'm not sure what you do if the volts and wire feed speeds are taped over like the above except set the volts and work the WFS to the sweet spot to see if you know what a proper mig arc would look like at any random setting...http://www.airgas.com/content/detail...=7000000000143Just go back again (stay sharp BTW).Matt
Reply:For 1/4" I like to set my 251 at 19 volts 300+/- wire speed.  I'm using 75/25 gas and .035 wire.  I use 18/280 on 1/8" to 1/4" fairly often also.  I'll post some pics if you'd like.  I think I have some 1/4" scrap in my barrel.My name's not Jim....
Reply:Originally Posted by Matt_MaguireHi BB70Chevelle;He's seen your work with the torch, straight, consistant and steady. Now he may be checking your heart, do you really want it.No offense but any 19 year old seems like a leap of faith for an employer.I agree with the above posts about bead width, and the real issue with that is too much energy is back in the puddle which can lead to poor fusion. Don't worry about that now, you're a student. There are instructors that would "dog" you about the posted welds just to see how far you really could go (they look really, really good for a student).As for settings you can help yourself here, check the airgas link below for some rule of thumb mig settings. Note at the bottom of the page are IPM settings for different wire sizes and burnoff rates for amperage wanted. The chart won't be better than +/- 10% but it is better than nothing and comes from the "total energy" mig equations that are out there. Using a tape measure with a 3 or 5 second pull on the trigger times 20 (for 3sec) or 12 (for 5sec) you have the IPM's. Volt/Amp mig charts are in your materials for class materials. I'm not sure what you do if the volts and wire feed speeds are taped over like the above except set the volts and work the WFS to the sweet spot to see if you know what a proper mig arc would look like at any random setting...http://www.airgas.com/content/detail...=7000000000143Just go back again (stay sharp BTW).Matt
Reply:Originally Posted by BoostinjdmFor 1/4" I like to set my 251 at 19 volts 300+/- wire speed.  I'm using 75/25 gas and .035 wire.  I use 18/280 on 1/8" to 1/4" fairly often also.  I'll post some pics if you'd like.  I think I have some 1/4" scrap in my barrel.
Reply:Took me a little while.  I had to clean off the bench first....Pics didn't come out very well, but here they are.18v 280 ipm vert down two passes.18v 280 ipm flat three passes pushing.19v 300 ipm vert down two passes.19v 300 ipm flat three passes pushing. Attached ImagesMy name's not Jim....
Reply:despite what the pics look like, all the beads had flat faces and wetted in well.  Pics of beads never seem to turn out well for me.My name's not Jim....
Reply:Like what was already said, your off to a good start and seem to have good eyes and hands.  The bad is that when your not allowed to finish a weld test something happened.  Like you say it could be a scheduling issue with school and the best thing is to go back and finish.   You definitely need to be able to run stringers and a weave in both stick and mig because at times you may only be allowed to run one type of style.  Also work on sizing the weld bead to the material thickness being welded because if your always running large on your beads that is extra time and money being spent.
Reply:Thank you for the pics and I can see my beads were definetly way to thick that I was doing. Tonight when I go to school I'll try running a few like those shown in the pics and will let yous know how I do.
Reply:Originally Posted by BoostinjdmMy name is not Jim
Reply:Originally Posted by BB70ChevelleThank you for the pics and I can see my beads were definetly way to thick that I was doing. Tonight when I go to school I'll try running a few like those shown in the pics and will let yous know how I do.I think you got it right...about not being available for shift work due to school. No one that knows anything will knock you for dialing in a strange machine.UA Local 598
Reply:Originally Posted by Boostinjdmdespite what the pics look like, all the beads had flat faces and wetted in well.  Pics of beads never seem to turn out well for me.
Reply:I think you will be fine dude. You obviously want this and are working towards it by asking questions on here so you can get that job next month. My settings are very close to boostenjdms. I like 19v 260ipm with 035 wire on a mm252s and 19v 270-280 on mm251s for vert down on most fillet welds 1/8th through 1/4 in. 251s seems to have a better arc imho. My volts might just be a titty bit higher because our shop is like 200 ft long and there is quite a bit of wire between the machine and the panel.
Reply:I should prolly mention that even when running stringers, I still weave about an 1/8".  If I don't, I get too much of a crown and the toes don't wet in as well.My name's not Jim....
Reply:It definetly can use some more practice as this cover was a bit inconsistint but, I think I'm getting the idea for the right size the bead needs to be though, They still apear to be a little larger then the welds you did so I'll try to get them a little smaller next week. I also did stringers for the first time aswell and like you said about doing a slight weave, I don't think I weaved quite enough as the top weld has a slight curve to it.These were with the settings at 19 volts and 300 for the wire speed. Teacher said they weren't bad the welds but, I'm not to happy with them just yet so I'll keep at it next week to try and get it down right and will let yous now how it goes.Last edited by BB70Chevelle; 04-30-2010 at 01:17 AM.
Reply:Stringers are better sized, try pulling your head back a bit and concentrate less on the puddle and a little more on torch travel speed. If you get too fast or twitchy you'll get plenty of feedback through the torch and by sound.300 IPM works out to 130 -140amps so you still will need a little weave (very little) like boostinjdm mentioned.Matt
Reply:Thank you all again for all your advice and help. I was able to get in some more practice tonight at school and I think I got it down pretty good now.Vertical down 1/4 inch plate 18 volts 260 wire speedSame setting but this one is 1/4 plate to 1/8 plate What does everyone think?
Reply:still looks a bit oversized to me, but I guess thats better than undersized.My name's not Jim....
Reply:Try keeping the width of your weaves down to 1 1/2 times the thickness of material.  So if you want to run a wide weave like that it should be done on thicker plate. That way you get a better feel for the difference in heat input of thin vs thicker plate.
Reply:All of your welds look oversized, but you already know that.What kind of job specifically where you applying for? It seems those welds would probably be good enough to get you in the door for a general fab shop. No offense, but just quickly reading this entire thread, it seems to me the employer may have passed over you for other reasons than just your weld. He said come back with more experience, that can mean a lot of things. As someone else said, hiring a 19 y.o. is a huge leap of faith for most employers. Especially in this job market when you are competing with people who are twice your age with 20 years of working experience. Sometimes reliability, dedication and maturity will get you further than skills alone, and at 19 it's hard to prove you have any of those.From the employers perspective it might be better to hire someone who has a proven work history and will show up every day than someone who has perfect welds with no work history.Last edited by slagmatic; 05-04-2010 at 03:07 PM.