TIG is harder than it looks

[John OlsenParticipant @johnolsen79199]

I am no expert, just an amateur at all forms of welding, so for what it is worth here is what I have learned in a year or so of playing around…

1 Cleanliness is everything. Especially with aluminium. Stainless is not so hard since it tends to be cleaner. Clean the filler rod too.

2 Remember to turn the gas on! Seems obvious enough but I have forgotten at least twice. If you do forget, clean the job again. (Use the right gas too, not the mixture intended for MIG. I haven't done that, but I gather it is not a good idea.)

3 If you touch the tungsten on the job, stop. Regrind the tungsten and clean the job again. It will not get any better if you try to keep on going.

4 If you are making stainless tanks, like I was on my first major job, do not flange the joints. A nicely fitted butting corner is much easier to weld and often does not even need filler.

5 Aluminium is harder to TIG, get some practice before trying anything critical with it. If it starts to get out of hand, stop and let it cool for a bit. Some of my best joints have that "stack of dimes" look, many don't!

6 Buy a reasonably capable machine, Having HF start in particular is good, scratch start is for experts, not learners. Arc force is good on MMA, but not needed for TIG. All those settings might look a bit daunting, but better to have them and not need them than vice versa.

I mostly don't use TIG for welding mild steel, I use the same machine but on the DC stick setting. I find that the welds I can do that way are so much nicer than what I used to get with an old AC arc machine that it is not worth expending the argon to try to do better with TIG.

I have a foot pedal, but I am not multidextrous enough to get much value out of it yet. The machine also does pulse, but I haven't made a lot of use of that yet either. I have welded stainless, aluminium , and copper, the latter being inch size plumbing tubing, quite thin in the wall. It didn't come out very tidy but it holds vacuum in OK.

Welding is a trade in its own right, as an amateur I do not expect to ever get to the level of the professionals, but with practice it is possible to do a reasonable job .

John

[Martin King 2Participant @martinking2]

Hi all,

I am getting on OK with my new AC/DC tig machine from RTech but really only on mild steel angle and flat bar in the 3-5mm thickness. Practice does seem to be the key here!

I have successfully built up a chipped corner of a Cast Iron vice with SiBronze brazing and repaired a small watchmakers lathe in a similar fashion. Neither looked that pretty but they came out OK after machining. Both items showed porosity which I suspect was from the carbon in the cast iron and the fact that it was difficult to get the joint REALLY clean.

Also with SiF one is not supposed to melt the cast only the rod; I found this really difficult when striking the arc as can be seen at the RHS of the joint.

Very difficult to guess the current also, this was at 85A with 2.4 tungsten and 1.6mm rod. Perhaps should have been less with such a small part?

Quite surprised at how quickly the Argon goes down even with only a 5sec post flow. Another expense to be costed in at £50 a pop from Hobbyweld!

I am looking into the courses offered by The Machine Shop in Leicester as they have a tie up with RTech and buyers of RTech kit may be eligible for a 4hr free course. Long way for me but maybe tie it in with another course and make a day of it; post COVID of course.

The plane cutters weld up OK but will need to switch to a 1.6mm tungsten and smaller cup I think. Again here I could do with some help with the best current to set on these very small parts, almost just a tack weld?

Cheers and Happy New Year to all!

Martin

[mark costello 1Participant @markcostello1]

2 hints that might help

Dip the filler rod in the very beginning of the puddle, not towards the middle as seems to be My habit.

With Aluminum just as You dip the filler very slightly raise the torch.

I am not an expert and will not be posting any pictures of My welds, Your eyes may be too sensitive.

[Kiwi BlokeParticipant @kiwibloke62605]

FWIW, a few tips for beginners…

Watching closely the weld pool can become hypnotically fascinating. All your concentration is focussed there, but you can end up staring at it, without really taking in any useful information – there's a lot of changing information in the picture, which is challenging to take in all at once. Before you reach the stage of 'unconscious competence', you need to reach 'conscious competence' and be conscious of what is really important to observe. I'd suggest you really need to concentrate on watching three things (for ferrous welding, at least):

1. Watch the weld pool width (across the direction of travel). Aim to allow the pool to grow to the same size as the previous pool, then add filler and move the same distance as before. This gets you nearer the 'stack of coins' appearance that's so pretty. This deliberate 'stop-start' torch movement is easier to control than a continuous movement. And easier still if you can use a slow pulse technique.

2. Watch the downwards penetration of the visible leading edge of the weld pool (applicable when there is a gap or vee between the pieces to be joined). Aim for consistent depth. Do make sure the pool isn't just sitting on the parent metal surface.

3. Watch the electrode position. Keep it at the recommended distance from the work and beware sideways wandering.

Magnification really helps. Spectacles and light leaking in from behind your helmet are a really bad combination. If you can't get, or don't want a magnifying lens for the helmet, get close.

Life is easier with a gas lens, and it saves gas too.

Of course, there's no substitute for good tuition and practice, practice, practice, but short-cut hints hopefully help…

[Ady1Participant @ady1]

Posted by Colin Heseltine on 30/12/2020 21:18:51:

I am also trying to learn to use a TIG welder. I started off using the MIG auto dimming helmet but was struggling to see what I was doing. Brought a Parweld True Colour vizor and this transforms things. I can now see the weld puddle. The other thing I did was by a x2 cheat lens to fit in the vizor. This increases the size of what you are looking at significantly. I wish I had bought the x2.5 now.

Trouble is I have not picked the welder up for a couple of months. I had intended to try and use for a few hours every week. I want eventually to be able to TIG ali.

Colin

I too have been having flash issues and detail issues with smaller items so got myself a parweld

I can confirm that MIG welding is a heck of a lot easier with a 60 quid parweld visor than a 25 quid standard unit, and that's without the magnifyer being fitted yet

So thanks for that advice, well worth the money

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