|
|
Hello all, I have just found these forums. I was given a MIG machine that had a problem in the electronics, after fixing that and wiring the building and machine, I am on a roll but I need some help in getting things right.I am pretty good at stick and weld mostly on tractors and other fairly heavy structural parts most often. So I am at least used to the idea of welding and the fundamentals.The machine I am using is a Power Mate 160A unit. Gas is C25 at about 20 CFH. The metal I am using is assorted mild steel plate and bar that was laying around the shop. Pretty heavy stuff for the machine but that's what I had.My first question is about setup of the machine and what I should be looking for. For most of this I was running pretty well maxed out on the voltage. At first the character of my arc was that it was sort of "hissing" and occasionally a large glob would build up on the end of the wire and sort of "pop" off now and again. Definitely not short circuiting the majority of the time though. I turned the wire speed up and got more of the bacon frying short circuiting characteristic to it. Both modes seemed to result in a good looking bead but the short circuiting mode was obviously faster with the higher wire speed. Can you explain what is happening there, and if there is any usefulness in the slower mode?My second question is in regard to fillet welding and just laying a bead on a flat surface. It seems that I am getting quite a bit more deposition of filler metal than I am used to in stick, in order to join the two pieces together or run a bead. I am more of the mindset to melt the two pieces together and let the filler just cover any gaps, however in this case it seems that more filler is going down than necessary, but at the same time not a very impressive puddle. I would like to know what to think about that.Thanks,Birken
Reply:My first question is about setup of the machine and what I should be looking for. For most of this I was running pretty well maxed out on the voltage. At first the character of my arc was that it was sort of "hissing" and occasionally a large glob would build up on the end of the wire and sort of "pop" off now and again. Definitely not short circuiting the majority of the time though. I turned the wire speed up and got more of the bacon frying short circuiting characteristic to it. Both modes seemed to result in a good looking bead but the short circuiting mode was obviously faster with the higher wire speed. Can you explain what is happening there, and if there is any usefulness in the slower mode?
Reply:Originally Posted by SandyI think this site would be real helpfull with the background you have. http://www.esabna.com/EUWeb/MIG_handbook/592mig1_3.htmFluxcore is by far more penetration and plenty of smoke and hiss to make a stick guy feel at home. Lot less fill ratio too.
Reply:Originally Posted by Birken VogtMy second question is in regard to fillet welding and just laying a bead on a flat surface. It seems that I am getting quite a bit more deposition of filler metal than I am used to in stick, in order to join the two pieces together or run a bead. I am more of the mindset to melt the two pieces together and let the filler just cover any gaps, however in this case it seems that more filler is going down than necessary, but at the same time not a very impressive puddle. I would like to know what to think about that.
Reply:Originally Posted by sstorkelThe close the tip is to the work, the more "heat" will be transferred. .
Reply:Hello Birken - it was funny to see your name pop up on here. I'm used to seeing it on thedieselstop - I haven't been on there lately, but JayBee is my name on there...
Reply:Originally Posted by slow6you mean transfered from the gun to the metal? or vice versa or both?thanks, your tips are good
Reply:Originally Posted by sstorkel DAMHIKT.
Reply:DAMHIKT: Don't Ask Me How I Know That
Reply:[QUOTE=sstorkel]DAMHIKT: Don't Ask Me How I Know ThatWell,alrighty now, I won't. Thanks for the update
Reply:Originally Posted by sstorkelDAMHIKT: Don't Ask Me How I Know That
Reply:[QUOTE=Birken Vogt] using is a Power Mate 160A unit. My first question is about setup of the machine and what I should be looking for. For most of this I was running pretty well maxed out on the voltage. At first the character of my arc was that it was sort of "hissing" [QUOTE]To me it says you have repaired the machine well - maxing out the voltage setting and the hiss tells me that the unit is in spray mode -that high amps ( high wire speed) are feeding in the wire where it is melted by the heat of the arc pool (where the voltage setting is melting off the wire) - is, as it should be. [QUOTE}My second question is in regard to fillet welding and just laying a bead on a flat surface. It seems that I am getting quite a bit more deposition of filler metal than I am used to in stick,[QUOTE] The above (high amps and high voltage setting) are the factors that produce your high deposition rates. If you want less deposition, reduce the wire feed rate (amps) and reduce your volts setting ( heat input).There is a sweet spot for the two, where one setting complements the other.Basically ,the wire speed controls amperage, penetration and rate of fill.The voltage control sets the amount of heat in the pool which controls the rate of wire burn off.As others have suggested if you work with ag stuff flux core wire may suit your needs, better. A caution here, may be that the machine would need to be able to be set to electrode positive to run flux core, as well as require the correct drive rollers and obviously dispense with the gas.Hope this helps youGrahameGrahamewelding instructor
Reply:I was thinking it was spray transfer but did not want to assume in my ignorance. But being it is a 160A machine, can it do that or is something else happening? Wire size is .035. Besides laying down a bead, which it was doing, it was also building up a big blob on the end of the wire which would occasionally "pop" and throw metal everywhere. I am wondering if it was not globular transfer instead.Birken
Reply:Small MIG units really can't do spray transfer especially with C25, it's either short-circuit or maybe you have gotten into globular transfer.The ESABNA and Miller info say spray transfer on steel can be done with no more than 15% CO2 - 85% Argon mixes. ESABNA lists spray transfer on steel with 0.035 wire at about 165 Amps minimum and 98% AR - 2% O2. ESABNA lists short-circuit transfer with 0.035 wire between 75A to 175A.Amps on a wire-feed machine is controlled by the wire-feed rate, and the wire-feed rate also obviously influences how fast filler metal is introduced. To slow down the amount of filler introduced, you can slow down the wire-feed rate, increase the torch travel speed, or use smaller diameter wire. |
|
发表于 2021-9-1 00:14:30