POLARITY on MIG

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Hey all. I just bought my Lincoln PRO MIG 175 at Lowes and I can´t just look at it without trying it(I need some extension cords for testing it out). But before I would like to hear some on you. On MIG (with gas) manual says you should put negative terminal to the work clamp. Positive then goes to the gun. FCAW (flux core) goes the other way. Negative is to the gun and positive to the ground. Which terminal is the one that concentrates 70% of the heat and which is the one that stays with 30%?I would like to run on MIG with the most possible penetration possible so is it achieved with what the manual says? would changing it will increase penetration or decrease?Of couse one of this 2 configurations is rated for low penetration. SO I would like to know which one. Or is it another reason for turning the other way the cables? (maybe flux core likes better the inverse configuration or I don´t know) I would also like to know, which configuration you guys are using for welding 1/8 " (.125) wall mild steel. I know Lincoln has a chart but hearing won´t affect. Another question is...Amperage is ruled by the wire feed speed. For thicker materials you need more amps, however on the chart this doesn´t seem to be the rule. So let me get this straight MORE WIRE SPEED = MORE AMPERAGE = MORE WELDING ABILITY (I mean of course for welding thicker materials) Am I getting this straight?
Reply:Don't try to bring the SMAW polarities into GMAW.  Go exactly with the recommendations for the process in the manual.Just remember that your voltage setting has to be sufficient to meet the requirements of the wire speed, which does directly control your amperage.Use the door chart settings, and then adjust wire speed to fine tune.  If necessary, try one voltage setting up or down and then fine tune with wire speed again, if the door settings are off based on your location's details.
Reply:Sort of lolYou have to stick to the polarity of the gas mixure and wire type.  NO if ands or butts!  Its not like stick where some rods you have a choice.  Not all flux wires are straight polarity...gun neg.   More wire means more amperage, however, the voltage must also be factored in as it will affect your arc and if you dont have enough voltage you wont get a good proper fluid puddle. Anyway, with wire to get deeper penetration turn up your heat, or put a bevel on the joint.  I need to bevel for MIG with thinner material than I need to with stick generally speaking, but it all depends.  Anyway, anything more than 1/4" needs a bevel, 1/8"-1/4" may be called for a bevel particuarly if you are grinding down smooth.  It depends on the specs the engineer calls out.  If you are doing this stuff on your own, then you make a judgement.  Ive never had a problem with not beveling less than 1/4", but I do a lot more stick.  Flux core also has more penetration than solid wire mig.  Its not because of the polarity, the shielding plays a bigger role in this case.  GTAW, differnt animal dont confuse the two.IF it Catches...Let it Burn
Reply:Originally Posted by elvergonHey all. I just bought my Lincoln PRO MIG 175 at Lowes and I can´t just look at it without trying it(I need some extension cords for testing it out). But before I would like to hear some on you. On MIG (with gas) manual says you should put negative terminal to the work clamp. Positive then goes to the gun. FCAW (flux core) goes the other way. Negative is to the gun and positive to the ground. Which terminal is the one that concentrates 70% of the heat and which is the one that stays with 30%?I would like to run on MIG with the most possible penetration possible so is it achieved with what the manual says? would changing it will increase penetration or decrease?Of couse one of this 2 configurations is rated for low penetration. SO I would like to know which one. Or is it another reason for turning the other way the cables? (maybe flux core likes better the inverse configuration or I don´t know) I would also like to know, which configuration you guys are using for welding 1/8 " (.125) wall mild steel. I know Lincoln has a chart but hearing won´t affect. Another question is...Amperage is ruled by the wire feed speed. For thicker materials you need more amps, however on the chart this doesn´t seem to be the rule. So let me get this straight MORE WIRE SPEED = MORE AMPERAGE = MORE WELDING ABILITY (I mean of course for welding thicker materials) Am I getting this straight?
Reply:You mentioned needing some extension cords to test it out.  Remember that the longer your extension cord is, the less power is delivered to the machine.  A buddy of mine ran his 175 off of a 50 foot extension cord and could barely get an arc to strike.  If you have to use extension cords, make sure you use the largest wire gage available.I r 2 a perfessional
Reply:Thanks, I made one out of 10 meters of gauge 6 cord, I think it is nice. The cable cover isSOOOOOOO thick and hard. I run it today with the machine settings for fluxcore, it is basicly a 7018 rod in a wire mod. Lol, it smells the same when burned  my hands would smell just like 7018 when run with AC (soo much easier to start an arc now  ) .....I´m actually thinking of leaving it with fluxcore, because I really liked the penetration, but I need to run it with CO2 too so I can check duty cycle and penetration. I really liked the machine, and it won´t go to up to J GNM =( it will only get to E soo I´ll need to run it with gas to decide what to do. Thanks all for the repplies =)Last edited by elvergon; 07-12-2006 at 02:29 AM.