309 wire and carbon steel

by Dolan Jahn
(central, SC,USA)

i'm practicing for state competition, and i miss read the wire type.

Thought it was ER70S6 wire, which i use frequently. But in all actuality i was suppose to use 309 stainless wire on carbon steel T-joint design, of 1/8" thickess, width of 4", and height of 2". I use this site frequently, and figured it was the best place to turn to, after visiting this site for 2 years; and not been lead wrong so far.

So after the rambling, could you offer any advice on a verticle T-joint 309 wire in 1/16, 3/32, or 1/8 wire. Any advice would help out tremendously, thank you


i am guessing that if this is for a competition, there is a drawing with a fillet weld symbol stating the weld size.

also, if thickness is 1/8" then weld leg size is probably not larger than 1/8"

That could be done with a single pass or with 2 passes. depending on time given and what you are comfortable with.

This joint is probably going to be judged by uniformity and accuracy of size of the weld leg.

if you walk the cup, you could probably use the 1/8" rod with a single pass using the lay wire technique.

or you could do 2 passes with the smaller rods to get the 1/8 leg size. that's a pretty small weld.

since its a t joint, you probably wont be able to walk the cup for the first inch or so...

a few tips for you are...

always snip the wire tip if it comes out of the argon.

use a sharp electrode ...a 3/32 is fine for this joint.

if you use the lay wire technique, keep a little pressure on the rod into the puddle to keep it from balling.

also , dont use too much torch angle, this will ball your filler too.

dont burn thru. you should not need more than 100-125 amps ...burning thru will bring oxides from the back side into the puddle

Return to tig forum.