Freehand vs Walking the Cup on a 3F tee joint carbon steel

A common TIG weld joint in welding school might be a 3F vertical multiple pass tee joint.

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While A 3F TIG multiple pass fillet weld might be uncommon  in industry, it is a  good pretty good training exercise that prepares for TIG welding socket welds.

I used 140 amps on DCEN

#6 gas lens cup with 15-20 CFH argon flow 

3/32” ER70S-2 filler rod

3/32” 2% lanthanated tungsten

For field welding, a scratch start tig rig would be a common setup but since I was in my shop, I used a foot pedal with machine set at 140 amps and I maxed it out.

I wanted to compare freehand to walking the cup on this weld so I freehanded the first half of each pass using a tig finger for a prop.

It is important to note that letting a weld cool between passes can be very helpful.

When a weld gets too hot, things can get messy.  The puddle can get full of oxides and does not flow the same.

That is why welding procedures often list a maximum interpass temperature. ( a temperature the metal must cool to before welding the next pass)

This 3F tee joint is good training for a multiple pass fillet weld or a socket weld where multiple passes are needed.

For this video I used a PrimeWeld TIG 325x with water cooled CK 20 torch and a weldmonger #6 gas lens cup.

I used ER70S-2 filler rod in 3/32” diameter. 

3/32” 2% lanthanated tungsten ( for DC welding 2% thoriated and CK LaYZr also work well)