Posted by Robin Graham on 08/08/2021 23:57:59:
- 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.
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.
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