Thread: Starting out with AC/DC TIG

Another thing that reportedly controls arc width when using AC is the AC frequency. A high frequency equates to a more focussed arc. Low frequency gives a wider one. My machine only does up to 200Hz, so I've never really been able to test this is any reliable sort of way.

I was also sharpening the electrode like Rusty, just rolling it with my fingers over a spinning flap disc untill i seen the drill trick i will try that

Haven't had as much time as I'd like to practice, but I did change to 1.6mm tungsten for my lap joints on 3mm flat bar and got some 1.6 filler to match. My ambition is to lay the really tight beads that Jody somehow does.

My biggest problem so far is losing sight of what's going on. Starting out is fine, let it heat up until the puddle fills into the centre and start to move. Adding rod to the front of the puddle is working well, managing not to dip the tungsten while holding a tight arc, and then I kind of lose sight of the arc and am barely seeing the puddle, I lose my alignment on the joint and suddenly there's the green flame of doom as the tungsten contacts the puddle (or rod). Then it's all a haze with an arc and puddle somewhere inside, and the finished joint looks quite good for the first 1/3rd and then gets ugly.

Having had this happen so many times, I think it may have dawned on me - I need to move my head as the weld progresses

Yep. Some good advice is to start in an uncomfortable position and move to a comfortable position. I often don't obey this rule and end up screwing up the end but it's easier the other way.

What works best for me is welding a small run around 100mm each time and only hold as far up the filler rod so i don't become shaky or lose accuracy of the arc and dabbing, i tried the whole first and second finger touching and thumb and pinky touch to feed the filler rod it worked well when i tried it and i felt comfortable just trying to feed the angry arc/weld with 1.6mm filler rod was a constant battle i find using 3.2mm filler rod far less effort and work and a much better weld

Once again your technique mystifies me. I struggle with 2.4mm sticking under about 120A. I've never used 3.2mm. And you should learn to feed smoothly and consistently if possible with your left (and right) hand. It's great to always have a constant distance of filler sticking out.

I don't weld fast not as fast as the Miller calculator, my rods could be 2.4mm i will have to check but i think they are 3.2mm, i found the thicker rods much easier to work with

the 1.6mm rods i was filling like a mad man i just couldn't keep up with filling the puddles and i ended up with slight craters

Another tip is to "prop" don't "lean".
If you are supporting your body weight with your elbow for example then it won't work when you find you need to move your head/hands to follow a weld.

When 1st starting out KISS stick with 3mm or thicker mild steel, align your practice coupons to weld towards you on an angle this way you will be able to see what you are doing for the whole weld.
Once you get more proficient swap hands and go from the opposite direction again towards you.
Also just do autogenous welds to start with to learn heat and speed control then start introducing filler rod into the equation... you can simplify that too by doing lay wire instead of dabbing... much easier and the filler is always enveloped in argon so less contamination.
Stacked dimes does not mean a stronger weld.

And keep your practice up, stopping for a few months is like almost starting again for a beginner like us

Had a moment to ponder a few of the bits of advice given in this thread, and one thing that dawned on me is that I really needed to sort out my positioning. For "benchtop" welding, I've just got a sheet of 6mm cement board over a 19mm plywood bench, so for welding small, flat things, I clamp them near the edge with the earth lead, which means I don't really have any bench to rest myself on.

So I took a trip down to the scrap pile in the back paddock where I knew there was a 450 x 600mm piece of 10mm plate rusting away and attacked one side with a flap disk and set in on top of the cement board. It had a bit of a hold in the middle, making me think it might have been a barbecue hotplate (but that doesn't make a lot of sense) so I drilled it out to 7mm and tapped an M8 hole with the innovate idea of being able to attach fixtures and jigs. Might even add more holes if I get motivated

With the ground clamp attached to one corner of my new work surface, I could place the job anywhere and in any orientation, which may sound bloody obvious, but with stick and MIG, you just tend to weld in whatever place or position the job tends to be, it's no big deal.

I then tried a fusion-only lap joint on 3mm bar with 1.6mm tungsten (no filler):
IMG_1479.jpg

and then with 1.6mm filler:
IMG_1478.jpg

I made a point of purposely moving my head around, which helped a lot when I started to lose sight of the puddle and arc position relative to the joint (you can see those moments on the first pic where there's lack of fusion on one side). Obviously needs a lot more practice (including how to finish a run), but I feel I am getting less worse

Nice work, Rusty.

Looks like maybe you got your angle wrong a few times without filler, although something else happened too.

You can tend more towards the lower plate I find. It'll absorb a lot more heat vs the top plate edge, which will just eat away much quicker.

Just come off the pedal at the end and then go back over the weld and feed a bit. It looks like you're doing the last two anyway. So just watch the heat buildup using the pedal and/or travel speed.

From one beginner to another fwiw.

Rusty try bending your torch head it might be a flexible model