learning TIG - pix on website - advice

Interesting. I'm not sure I have ever seen this notch you refer to, but I'll defer to the exoerts.

J

I have observed the notch you speak of, but it's visibility is affected by the type of base metal, thickness, amperage, and shielding gas, so I wouldn't necessarily try to base my technique on it.

Is there a good set of recommendations for TIG welding in general?

Dial your amperage in correctly, gind your tungsten correctly, and then move the tungsten in until you get your puddle.

I have posted my guidelines on amperages many times, but here they are again.

for everything.

Here is an exercise to practice when not welding.

Level 1

Take a 3/8" steel washer. Place it on a piece of white paper. Take a nice sharp pencil. Place the tip of the pencil against the paper inside the washer. Now start swirling the pencil tip around the inside of the washer to draw a circle on the paper. Keep circling the inside of the washer, while nudging the washer across the paper. Try to end up with the washer traveling in a straight line across the paper. You should end up with a long swirl pattern across the page. Keep parcticing until the swirl pattern is even and in a straight line.

Level 2

Same setup, with one change. Once again slide the washer across the page while swirling the pencil tip around the inside of the washer, but now DON"T touch the paper with the pencil tip. This means being able to hold the tip of the pencil within about a

1/16" of the paper without touching it and without lifting out of the washer.

Level 3

Do Level 2 while standing next to the table without any part of your arm resting on the table.

Level 4

Move to a 1/4" washer.

This exercise comes from a gas welding textbook from 1929, and it still works quite nicely to train your muscles for floating the torch.

Normally you do not swirl the torch while TIG welding, but this still works as an exercise to improve muscle control.

I found I could get similar results on aluminum (3/32) by carefully reducing the amperage and slowing down my travel speed. My welds suddenly went from tall to nearly smooth and full penetration. I did not see any notch, though.

J

I have to admit I have just had a terrible time getting horrible welds and being unable to do anything to get them right. This "notch" thing seems to have been a "red herring" - a false lead. I must have been keeping something else controlled which was actually giving me these promising-looking welds. The instructor reminded me and a fellow student that controlling your weld-pool is the key to most welding processes. After a long time of never seeing a good weld, I went back to the absolute minimum current which would create a weld-pool, then played around with it, filling it and running it forward. Before long I was producing welds which indicate there is hope for me yet.

That minimum curretn which would sustain a weld pool - it was far below the "Amp per Thou" rule. I think the "sustain a weld-pool" current was less than 40A, whereas for 1.5mm sheet the "rule" would indicate 60A. When I tried 60A I had to run very fast and got an elongated-pear-shaped weld-pool. Is there something I have missed here?

RS

The 1 amp per 0.001" gives you some headroom. That is what your foot pedal is for.

>

I am also in the process of learning welding aluminium (i posted my experiences in another thread) and I think the "rule" is correct, but most weldors use a foot pedal. So the rule should be read: start with

60A untill the piece is hot and then back up. Indeed the current to sustain the weld pool (as opposed to start it up is lower than 60A. One of the problems with aluminium is that it is a great heat sink...

Note that the rule does not take the size of the piece into account and it should. If you weld tiny pieces of 1.5mm, the heat sink effect will be low. If you weld a big 1.5mm tube, more of your heat will escape along the tube.

I have a torch mounted slider rather than a pedal but the principle is the same. It controls the current, at least on my machine, from zero to what is set on the panel. I find I need to back off more and more as the work heats up.

Ted

As Ernie said, the foot pedal is to allow us the control needed to adjust for changes in the work. Coming up to an edge, or the end of a piece will require an active foot. That's one of the things I like best about Tig is the control!!

J

I've been taking a piece of scrap the same thickness and playing with that to see where the threshhold is for forming a puddle, then work from there. I have found that using less amperage is more.

J