Dipping a toe in TIG - what do I need (apart from skill)?

I have a Parweld 160A MMA inverter welder which was marketed as MMA/TIG - it has a 'lift TIG' setting. I'm now thinking about trying to teach myself TIG using this machine as a power source and I want to cost it up.

1. What I know. I'll have to get get an argon bottle with regulator and flow meter. That looks like £200 - £70 deposit on the smallest bottle from Hobbyweld, £70 ish for the gas, maybe £60 for the regulator / flow meter. Also I'll need a torch which leads to:
2. What I know I don't know. This is a quite wide category. I had a look a Parweld TIG torches and they seem to be in the £150 ish range, but I don't understand the jargon - what are 'dual cable' torches for example? Do you get the gas line as well as the cable? If so, what fittings? Then there are much cheaper offerings elsewhere - but will the cables fit my Parweld (sort of bayonet cable plug) welder? Are these things standard size? I could go on about the (to me) mysteries of gas lenses, but I'll leave it here for the time being.
3. The stuff I don't know I don't know. Well, I don't know, but  I live in hope of finding out.

I've done a fair bit of searching and have found plenty of stuff about technique but haven't yet found a basic starter's guide to the equipment needed.

Any help would be much appreciated.

Robin

Edited By Robin Graham on 09/08/2021 00:08:08

Edited By Robin Graham on 09/08/2021 00:09:37

For the gas I use a company called fosse gas in Leicester, really nice guy, operates from a small warehouse in his back yard, I've got refills in the evening and weekend, £95 to 'buy' a 10ltr bottle, no rental you own it, and £30 for refills.

I'm not familiar with your welder, if it's scratch tig and you don't have high frequency start or auto gas, you'll need a torch with a gas screw knob, this means you manually turn the gas on before a weld, and turn it off after.

Edited By Pete. on 09/08/2021 04:01:02

I'd go for the largest Ar bottle you can afford - you'll end up getting through quite a bit of gas because it sounds like your machine may not have sophisticated gas control. Anyway, you're going to do a lot of practicing, aren't you?

Also needed: auto-darkening helmet; proper TIG gauntlets - sensitive enough for good filler rod control; a few Kg of filler rods, of various sizes; tungstens; tungsten grinding facilities.

Your machine may start best using thoriated tungstens. But thorium is radioactive, and, although from a distance the electrodes pose no hazard, inhaled thorium dust is very nasty. If you're going to have to grind, you must be careful about the dust. Because of the radioactivity problem, and with the availability of high frequency starting, there's been a move away from thoriated tungsten. Lanthanated or 'rare earth' tungstens are fine for most steel work.

The grinding wheel used for tungsten grinding should not be contaminated with anything else. You can get away with an angle grinder and suitable flap abrasive wheel. Hold the grinder, wheel upwards and horizontal (in a vice?) and hold the tungsten in a slowly-rotating (cordless preferred) drill.

Gas lenses are good! They allow less gas to be used and facilitate access to the work. Find out all you can about them. No real need not to use one.

Look at Rapid Welding's web-site. They carry CK torches (and everything else you'll need). It would be a good idea to get the feel of a torch before you buy - you need something over which you can have fine control. The smaller CK torches are nifty, and come with a very flexible hose that doesn't try to take control of the torch's position.

While you can learn to TIG on your own it's a very steep learning curve.

You will save days of practice and a lot of expensive material(metal, gas, electrodes etc) by having a couple of hours tuition using your machine. If you can weld with oxy-acetylene you already have some of the skills.

You'll need to sharpen lots of electrodes with a lift-start.

Ensure that your helmet has lots of settings, as you need to see what you're doing at low power

From somebody who was in the same situation at the end of last year (with a dedicated TIG set):

The socket on your machine is a 'Dinse' or 'Dinze' connector (35-50 if Google is to be believed). This is a very common size (the other common size is smaller) - it's easiest if your torch set comes with one already attached.

You will need a valved torch so that you can turn the gas on and off as (it appears that) the machine doesn't have a gas solenoid. It's easiest to buy a 'torch package' which comes with cable / hose / sheath and often a set of consumables.

The cable/hose needs to be one with a separate gas hose, (not a 'single hose' setup where the gas flows up the middle of the Dinse connector and the power lead is inside the gas hose, although adaptors are available). You will need a hose from your gas regulator with a suitable coupler for the gas connector on the torch cable/hose. Most gas fittings are 3/8 BSP Right handed, but some Chinese torch sets are metric - M10x1.0 seems common.

As above, get the biggest gas cylinder that you can. Note that different suppliers fill to different pressures - Hobbyweld, I think are 137 Bar which is quite low. To work out how much gas you're actually getting, multiply the cylinder capacity by the fill pressure.

Torches come in different size formats and water or air cooled - for simplicity / cost, stick to air cooled. Choices of air cooled torches are 9, 17 or 26 format (loosely based on CK model numbers). 9 is small, and neat, but limited to ~100A (or about 3mm mild steel, but will get very hot at this), 17 is a bit bigger, but still quite nice to use - limited to ~150A. 26 it more unwieldy, but can handle 200A+ (actual current ratings vary slightly by manufacturer, but are roughly of that order). Unless you have very specific requirements, I'd suggest looking at 17 size torches with a valve (usually designated something like 'WP17V' ) .

I have a Kennedy WP17 torch (from Zoro) which seems to be decent quality & fairly flexible - I'm sure they used to do a valved version, but it's not there now.

The torch may/may not come with a set of 'consumables' - back cap, collet, collet holder & ceramic cup. IME, these aren't particularly consumable (bar breakage). What comes with the torch should see you through your first few months of practice IMHO. If you don't get any with the torch, you will need to buy the correct set (which can be a bit bewildering). 17 and 26 sized torches share the same consumables; 9 series torches are smaller. Cup sizes are numbered by diameter: Get a 'middle of the road' cup - something like a 5, 6 or 7 to start with, but don't go overboard. There are cheap sets of consumables with a few different sizes on Amazon, etc. that appear to be perfectly adequate. You will come to find situations where a smaller (for tight fillet welds), larger or longer cup is needed, but they are cheap to buy when you know better what you need to suit the welding that you are doing. Larger cups need more gas; smaller ones are less forgiving. As long as you haven't gone to extremes, cup size is irrelevant when you're practicing.

Gas lenses need a different type of collet holder. The full sized ones are quite long, but the 'stubby' versions aren't much bigger than a standard ceramic cup. I would use them out of preference, especially if there's a requirement to have the tungsten sticking out further than usual. If your torch comes with standard consumables, I wouldn't bother changing them until you've had a bit of practice - Gas lenses can get contaminated by spatter when you do things like losing gas shielding because your torch position has drifted (or forgetting to turn the gas on!), so not ideal for your first steps. They won't make the difference between success and failure in learning, and there is an argument that you learn to be more consistent, more quickly, with a standard cup.

What are (very) consumable are the tungsten electrodes! Buy a pack! There is perpetual discussion of the "best" type of tungsten. Many of these differences are only relevant to AC - with inverter welders, I think the differences are subtle and linked to personal preference (there are umpteen videos comparing them on Youtube). It will not make the difference between success and failure when learning TIG. The advice I was given, and will pass on it to buy a pack of 2% lanthanated electrodes (pale blue colour code) in 2.4mm and stick with them. This has worked for me on mild steel & stainless (DC) and aluminium (AC). (You need to make sure you have a 2.4mm collet holder / collet in your torch.)

I have seen a couple of decent videos on setting up lift start TIG - I will add them if I can find them again.

Good luck  - I am by no means fully competent, but find it a very rewarding process. 

A

A few videos, as promised.

The first is American, but bear with it - He summarises a lot of (IMHO) very sensible advice in one place. I forgot to mention filler metal above, but he also covers that well. His video on how to assemble a TIG torch is good, too.

The only thing I would add to the post above is to get a cheap 'peashooter' style flow meter so that you can check the gas flow at the torch, rather than trusting the regulator gauge.

Edited By Andy_G on 09/08/2021 18:34:31

I use a ck17 sized torch for my TIG. I got the actual CK one with super flex cable on it and it’s way nicer to use because of that - heavy or inflexible cable is a pain- TIG is supposed to be the sensitive welding process after all.. The torch is 150 amp rated (100% duty) - duty cycle is something to watch on a cheap torch.

I use purple E3 electrodes now (previously red and grey for dc and ac respectively) They seem good all rounders, but I haven’t experimented with lots of different types.

Oxy experience is useful, but on a TIG you can’t just pull the torch away to reduce the heat. Took me a long time to relearn that reflex…

Getting comfortable and supported in welding position is important. I was welding upside down under a car at the weekend - MIg would have probably been easier, but we use what we have. Getting well positioned for those shenanigans is even more important.

An autodark helmet is a good idea. Especially with a scratch start - one less thing to think about.

Clean material is a must. Not just a quick wire brush, but proper clean and shiny. With OA you can getaway with suboptimal prep, not so much with TIG - fit up, clean, supported positioning etc - all make a huge difference.

Dave

I was told that the more sophisticated kit with the foot pedal was worth the extra money.

A foot pedal is on my list to organise, but it’s not super useful when lying on the floor…

I was going to look at a torch mounted slider but I’ve not got round to it yet

Dave

Robin post the exact model you have ,then you will get more accurate comments. I.E Knowing if it has a gas selonoid .

Steve.

I'd agree with the bit about having to unlearn reflexes. I still have a tendency to want to pull the electrode away when I finish, when of course the correct thing is to release the button and wait until the gas cuts off.

With DC only you will not be able to do aluminium. The scratch start will be a bit of a limitation too, but I guess better to have a try with what you have rather than spending a lot on new equipment. If anyone is thinking of buying TIG equipment as a learner, I'd suggest that you go for something more than the bare minimum. The features I would suggest you want to have would be HF start, which makes it a lot easier starting the weld, and AC (as well as DC) which means that you can do aluminium. Being able to do aluminium turns out to be a very useful bonus feature that I hadn't really thought about when I got mine. I had been thinking mainly in terms of stainless steel tanks for the boat, which it does really well.

If it doesn't have a gas solenoid you should be able to add one externally. I've seen a video on Youtube where a guy added one to one of those very cheap very small DC welders that you see advertised. Thus turning a DC MMA welder into a simple TIG machine.

regards

John

On a couple of occasions I have had the foot pedal between my knees when doing positional welding with my my TIG, would agree though that a torch mounted slider is a more comfortable option for positional work. But I would be surprised if any scratch start TIG had the facility for either option.

You have a PM, Noel

Thanks for replies.

Noel, I have read and replied to you PM - thanks for your offer of assistance.

After reading and digesting all replies I think that I might be dipping my toe in waters much deeper than I first thought. But I am much more informed now, and in a better position to make a decision.

Thanks again, Robin.