ok so im cutting my quater panels on my miata to fit bigger wheels under the flares.
i got them cut and rolled and ready for welding.

i did my best with a roloc disk to clean up the metal

im using a millermatic 175
my heat is on 2.5
my speed is on 40-50

tank meter says 2000psi
flowing at around 20
75% AR 25%co2

im getting very porous welds, the look crappy and dark. like pitted. very terrible penetration, when i turn up the heat i blow right through the metal.
every thing i try isnt working. i thought cause im working outside i may have an issue with breeze blowing away my gas. but i cupped my hand over the welding area to hold in the gas and still no luck. so my next question is, how do i know for sure that im getting constant gas flow when welding. if i put the gun up to my ear i can hear a quick puff. but if i hold the trigger i hear nothing. where would you guys start in my situation. i need to make this work cause if i can get this thing welded back good, the car is shot and i have alot, i mean alot of money into this car. i think that the issue is with the machine. cause even though i dont have much welding experience, i should still be able to get a clean tack. and i cant even get that

 

You should hear a hiss of gas when you're on the trigger. I'd personally start by taking the line between the regulator and the welder off, and turning the bottle on...If you get gas coming out there than you know the issue isn't the regulator. Then reconnect the line to the regulator, leave it off the welder, and turn the bottle on again...If you get gas again than it isn't a problem with that line either.

Just gotta work your way backwards to rule things out. It could be anything.

 

so i went out today and got some clean 22ga sheet metal to practice on. its weldable non coated. yesterday i was running the machine on the extension cord( my roommate built it for the welder out of heavy gauge wire, its not a cheap cord). but anyway i decided to run the machine directly from the wall to see if it made a difference. i cleaned the metal with acetone. i tried some diffrent speeds and heats. but im running 2 on heat and 45 on speed.

this is what i got

so i pulled the gas feed line from the machine and turned on the tank, i can hear a slight hiss, and if i plug the end of the line with my finger for a couple seconds and take it off i hear a puff. my question is how much gas should really be coming out. should it be a very noticable hiss, where i can actualy feel pressure if i hold it upto my hand??

thanks

ps, my friend who does fabrication and welding told me for welding sheet metal to not do a bead, instead to make a series of overlaping spots, so thats what i was trying to do

 

what wire are you using?

 

hobart er50s-6
.024

the other numbers on the spool say
heat 63005
s305401-019
hb-28

 

I didn't read what you posted, but the pics posted above is poor gas coverage. When i have run out of gas while MIG welding it looks the same. Hope this helps buddy

 

can someone confirm what the gas flow from the reg feels like, if i hold it to my hand should i feel pressure?? i can hear it but i cant feel it. im almost thinking that the reg is broken maybe? or the gauge is broke

 

I run 7-15cfm

 

are you using a ball float or a needle gauge? I've used the needle gauge ones before and they never seem accurate, always had to bump the gas up a little more. Ball floats are the way to go IMO

 

Do you have the polarity switched?

 

needle gauge, i got it set to around 18-20
the polarity is right for solid wire. atleast its what the sticker on the inside of the door says

 

We used about 25-30 on the needle gauges I used. Try bumping it up slightly. I'm still pretty new to welding also though so this is just my guess.

 

You aint got gas, no need to bump it up to 30. 15 will do just fine.

 

For the 25-30 I only meant that in regaurds to possibly his needle gauge is reading under like the ones I worked with. I know that if it's actually flowing that its not needed

 

what unit of measurment are you guys using on your gauge, CFH or LPM? i went and cranked up the reg, 20-25 LPM, before i was looking at CFH and had it around 20. so im almost maxed on the gauge. well this was my results. 90% better


keep in mind i was doing this in a pretty dark garage tonight, so i couldnt see where i was going as well

 

It was definitely the gas. When our welder runs out of gas that splatter ish is what comes out.

 

That swisscheese looking weld is known as porosity...need more gas,deffinately a gas coverage issue....justin

 

Looks better but also looks like you should try some very small clockwise circles to keep the puddle pulling left. and also turn the feed down just a bit more.

 

looks alot like mine were. lets see a pic of the gun. mine, from the manufacturer, came with this really narrow plastic cup that was a good half inch behind the feed tip and wasn't allowing for full gas coverage, so i got a larger metal one that actually surrounds the tip, so all the gas covers the weld, unlike the other, which appeared to just rise the second it came out of the gun, giving little to no coverage

 

also, on the proper tip, you can turn the gas back down to about 12ish