I ran into a similar problem when learning to tig using scratch start and a stick welder. On 1/8" steel butt joint I would run a little to the hot side and use a 3/32" rod to chill the puddle. Less than 1/8" steel was even less fun.

After a few months (off-and-on), including using a high freq box on aluminum, I got really tired of fiddling around with amperage and using speed and filler rod size to compensate.

Eventually I spent $225 and bought my Airco tig and a foot control and found out tig was way easier

The problem I was having is everything I weld is a different item each time - so I had to spent too much time on scrap getting dialed in instead of getting work done.

If I wouldn't have bought a real one I would have gone back to mig/stick only.

 

Filler size is a balancing act. Bigger filler allows more fill per dip. However bigger filler also chills the puddle more and requires a hotter puddle on average.

1/16" filler should be fine for what you are doing. Remember when you go to bigger filler, you need a hotter puddle to melt it. Key is to always remember you melt the filler with the puddle NOT the arc. 3/32" will start to get tough on 1/8" material. 1/8" will be super tough as the material and filler are the same size. All the tech school uses for steel/stainless is 1/16".

Next time you get filler you might get S6 filler vs S2. You may find it a bit easier to work with, and it deals a bit better with contaminants than S2.


To me your biggest issue is amps. 85-90 is low to me, about what I'd use for 14 ga. I doubt I'd be colder than maybe 110 amps on but joints. Most likely I'd be in the 115 to 125 amp range, even with no pedal.


I'll be honest with you, I doubt you have enough hood time in yet to do well on but joints. It takes a fair number of hours to get in enough practice to get to this point. Most students even with an instructor looking over their shoulder don't get thru lap joints in 40 to 60 hours of weld time. The tech school runs joints in a specific progression for a reason. Each "skill" builds on the last one. beads with no filler let you get a simple feel for what things like arc length, travel speed and the pedal ( if you have one) do for you and how each changes the puddle in different ways. Then we go on and add filler to the mix. At this point you learn the basics on manipulating two different things at once, but you also begin to see how adding filler to the puddle effects it. After a bit we work on overlapping beads. This helps you learn to get the puddle to go where you want it so you can "aim" your bead,

Next comes joints, starting with lap joints. The lap joint is very similar to the overlapping bead, but now you have an edge you have to work with. The lap has the greatest heat sink area and is the easiest to deal with heat control. Next is T joints. Now you have a thin edge to work with. Next outside corners. Now you have two thin edges and a root you need to work with. Too cold and you don't melt thru the root. To hot and you either loose the root and blow holes, or you melt down the edges too much. The V at the corner is very close to what you get when you do bevel buts. Next would be but joints, Bevels, gaps and tight buts. Each has it's own "problems" that have to be dealt with. But joints are last because they require the most skill at heat control. Once you get those down, you change positions and start the procession all over again.

Filler is one way you can cool your puddle. Use the filler as a heat sink to cool the puddle so it's under control. Also you can move in with your torch to decrease arc gap and cool the puddle, or you can move the arc more onto the side of the piece where it can take more heat. on gapped but joints I'm constantly moving from side to side with the torch to control the heat. In some cases you may be doing all 3 at one time.

 

DSW - Thank you. A very solid and informative post.

 

yes, thanks. I was told that laps were the hardest joint, which is why I was starting on butt welds. I will try some laps. As per your prior advice, I started with beads no filler. When I felt comfortable with that, I progressed to beads with filler, then padding/stacking beads. I also spent some time with Zap at his clinic, which helped. Now I comfortable enough with beads that I thought it time to move onto some joints.

 

You could always try jamming in more filler rod with the current 1/16" rod. Sometimes it makes more sense than going up a rod size because it doesn't take all that much heat at the puddle to melt 1.5x as much filler.