iam gonna start on my manifold and i want to know what size filler rod should i use on ss sch40? thanks for any info guys...

 

I generally use 1/16 but I use 3/32 for head flanges.

 

ok thanks man...i also have to run tri-mix gas for ss dont i? or can i run pure argon?

 

i use what ever size i need, if it seems like i am dipping too much then i go a little bigger. i have had no problems using strait argon, only thing is if you want the penetration on the backside to look nice you have to purge the air out with argon.

 

Has anyone tried on Sch. 10/40 using ridiculously large filler rod and a good amount of heat to get good penetration on a single pass?

 

It is not a good idea. The puddle will wander more, and the weld will be more inconsistent and uncontrollable.