[Mvtepixels]

Hi, i'm an hobbyist welder, i'v been welding with a 30 years old buzz box for the last months, it's heavy and kind of tricky to weld with it, so i bought an inverter ( Nutool 140 AMPS), it burns rods like butter, when welding normal steel it works very well, but with stainless steel it's a different story, when i weld stainless steel the slag is very hard to come off, with the old buzz box the slag comes off without even touch it, with the new inverter i have to hamer the welds very hard and the slag still not come off tottaly. Does anyone know why it hapens ?
The old buzz box welds at 50 volts AC and the inverter welds at 70 volts DC, is it the cause ?
I did a test with both machines on the same conditions on a 2mm sheet metal and took this picture:



Rods:

[Poland308]

SS stick weld slag is notorious for coming off hard. Biggest thing is let cool and it will start to pop off all on its own, it’s designed to work like that. Until the weld is cool enough you will just fight it, if you tried to get it off when it was still hot then it usually looks like your pictures, and it almost makes it stick on there even worse. Maybe that’s just me.

[tweake]

try dropping your amps a bit.
AC is a bit cooler than DC.

[Mvtepixels]

SS stick weld slag is notorious for coming off hard. Biggest thing is let cool and it will start to pop off all on its own, it’s designed to work like that. Until the weld is cool enough you will just fight it, if you tried to get it off when it was still hot then it usually looks like your pictures, and it almost makes it stick on there even worse. Maybe that’s just me.

Thanks for your reply Poland 308, i did that experiment, with the buzz box the slag went completely off after 1min, with the inverter i waited more than 10 min but only went off small parts of the slag, the remaining slag looks like black superglue. No matter how much i wait, it don't pop off

[Mvtepixels]

try dropping your amps a bit.
AC is a bit cooler than DC.

I did that, 45, 40, 35, 30 amps... the problem remains. I've been searching the internet for answers, and i got to the conclusion that the high voltage might be the problem, my inverter welds at 70v, on the rod's box appears 50v on the description... but that's just assumptions, i need more information.

[tweake]

try dropping your amps a bit.
AC is a bit cooler than DC.

I did that, 45, 40, 35, 30 amps... the problem remains. I've been searching the internet for answers, and i got to the conclusion that the high voltage might be the problem, my inverter welds at 70v, on the rod's box appears 50v on the description... but that's just assumptions, i need more information.

i take it you havn't put a meter on to check.
i doubt its 70v welding voltage. might be 70v ocv.
inverters are not as predictable in their welding voltage like transformer machines.
the ocv on the rod box relates more to transformer machines.

did you try increasing amps?
sorry i should have asked earlier.
unfortunately i have not stick welder stainless. i don't know if its sticking due to being to hot or to cold.
i'm wondering if transformer run voltage is a lot higher and actually getting a bit more heat at lower amps.
also what is your arc length like?

[tweake]

i see esab actually list a weld voltage for those rods. to me at the moment it does seam to require a high run voltage.
so i wonder what the inverter welder is like running 6011?
if its got a cel or 6010 mode try it on that.

[Mvtepixels]

i take it you havn't put a meter on to check.
i doubt its 70v welding voltage. might be 70v ocv.
inverters are not as predictable in their welding voltage like transformer machines.
the ocv on the rod box relates more to transformer machines.

did you try increasing amps?
sorry i should have asked earlier.
unfortunately i have not stick welder stainless. i don't know if its sticking due to being to hot or to cold.
i'm wondering if transformer run voltage is a lot higher and actually getting a bit more heat at lower amps.
also what is your arc length like?

I measured the voltage on both machines with a multimeter, but not while they weld, don't know if i should also measure it while welding...
I did increase and decrease the amps but the problem remains.
I try to maintain a short arc, also one thing i notice is the penetration on the inverter is higher than the buzz box, working with the same amperage on both

[Mvtepixels]

i see esab actually list a weld voltage for those rods. to me at the moment it does seam to require a high run voltage.
so i wonder what the inverter welder is like running 6011?
if its got a cel or 6010 mode try it on that.

I never welded with 6010 or 6011, in Portugal it's a pain in the ass to find this rods, in my country the shops love 6013 ... but i definitely need to give it a try

[snoeproe]

I’ve done a fair bit of stainless stick. The slag usually pops off on its own when the weld cools. Once cooled, the slag comes off easily.