Tungsten sizing for thick to thin

[Moby]

Caveat: Brand new to TIG welding

I was welding some 16ga to ~3/8" over the weekend (new exhaust for my FJ-62, this was for the manifold flange to downpipe) and I sized the tungsten I was using (2% thoriated) for 16ga. This seemed to work OK and I could get both the 16ga pipe and flange to puddle pretty nicely but the torch got really hot really fast. Machine is a Miller Dynasty 200 set at 90 amps (probably using 80) with an air cooled 150 amp torch, Argon at 20 cfm. I'm wondering if sizing up on the tungsten would have helped or is recommended for joining thick to thin.

 

[94cruisercal]

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[Pin_Head]

The size of the tungsten doesn't matter so much as the amount of current you are using. The tungsten is sized according to how much current you are using. An air cooled 17 series torch should handle welding at 90 amps with no problem. Even though it will get hot, it is nothing to worry about. 90A is a little light for the 3/8 inch part, so maybe you have to go slow and dwell too long on it. Bumping it up to 150 will let you go faster and put less total heat into the part.

 

[Moby]

The size of the tungsten doesn't matter so much as the amount of current you are using. The tungsten is sized according to how much current you are using. An air cooled 17 series torch should handle welding at 90 amps with no problem. Even though it will get hot, it is nothing to worry about. 90A is a little light for the 3/8 inch part, so maybe you have to go slow and dwell too long on it. Bumping it up to 150 will let you go faster and put less total heat into the part.

Yeah, that sounds about right, I was having to go pretty slow. I'll try more amps next time. Thanks!