[evading]

Hi,

I have a question regarding power settings when welding t-joints. I know the rule of thumb with 1 amp for every 0.01" thickness and 2 ipm/amp for .030 wire.
But in a t-joint I'm not trying to get fusion all the way through the thickness of the material... right?
I want to have good fusion all the way down in the corner of the joint and to the edges of the weld. But is that very dependent on thickness? I realize that thicker material wicks away more heat, but apart from that?

Are there any rules of thumb like the one above for MIG welding t-joints or is it always the same?

With the above rule of thumb I get a wire feed speed of 12m/min for 030 wire for 6mm material and that seems like a lot to me (it is at least hard for me to handle consistently).

Thanks
Einar

[Oscar]

Hi,

I have a question regarding power settings when welding t-joints. I know the rule of thumb with 1 amp for every 0.01" thickness and 2 ipm/amp for .030 wire.
But in a t-joint I'm not trying to get fusion all the way through the thickness of the material... right?
I want to have good fusion all the way down in the corner of the joint and to the edges of the weld. But is that very dependent on thickness? I realize that thicker material wicks away more heat, but apart from that?

Are there any rules of thumb like the one above for MIG welding t-joints or is it always the same?

With the above rule of thumb I get a wire feed speed of 12m/min for 030 wire for 6mm material and that seems like a lot to me (it is at least hard for me to handle consistently).

Thanks
Einar

The depth of the fusion into the base materials certainly doesn't have to go all the way through the thickness, but it should go fairly well into the corner and into the sidewalls as well. T-joints and inside corner joints in general use more amperage than outside corner or edge joints. Practice on scrap of the same thickness and cut-polish-etch with a phosphoric acid (rust remover) solution, and you will know for sure. the 1A per 0.001" applies roughly for large metal mass up to about 0.200" of base material thickness or so. There is always tweaking to do; as you can see from my pic below, thick-but-small parts don't necessarily need 1A/0.001" guidelines. For the short circuit welds, I was running 629 ipm with about 10-12mm ctwd. You need the wfs to get the amperage up.

[weldin mike 27]

When trying to find a nice setting, turn the wire down until it hisses. At this point, you won't have enough "punch" to get root penetration. Now slowly increase the wire speed and listen to the noise. It should be a combination of hiss /crackle /even cloth tearing. If you get to a full on machine gun noise, and or feel the gun stuttering, you have too much wire. At this point you won't get nice starts, it'll be stubbing and carrying on until the arc hears up. I hope this helps.

[tweake]

Hi,

I have a question regarding power settings when welding t-joints. I know the rule of thumb with 1 amp for every 0.01" thickness and 2 ipm/amp for .030 wire.
But in a t-joint I'm not trying to get fusion all the way through the thickness of the material... right?
I want to have good fusion all the way down in the corner of the joint and to the edges of the weld. But is that very dependent on thickness? I realize that thicker material wicks away more heat, but apart from that?

Are there any rules of thumb like the one above for MIG welding t-joints or is it always the same?

With the above rule of thumb I get a wire feed speed of 12m/min for 030 wire for 6mm material and that seems like a lot to me (it is at least hard for me to handle consistently).

Thanks
Einar

i don't do stuff all of mig but my $0.02

my chart here says to use minimum 0.9/.035 wire at about 9--9.7m/min for short circuit. i'm guessing smaller wire will be right into globular transfer.

[evading]

Thanks for all your replies.

It turned out that practicing a bit did all the difference, who would have thought

My welder is a bit finicky at these higher amp/wfs settings so I have to be careful when adjusting the settings.

// Einar