Boynextdoor

Quoted from Mick on Wednesday, 20 April 2022

For anyone that's interested I have a bit of an update to this thread. I decided to invest in a small portable inverter TIG welder as my big unit is simply too large to drag around.

My main prerequisites were lightweight and cheap. Also as I only wanted to weld steel, it only needed to be a DC set.

Looking around (on ebay) I saw that there were many cheap inverter DC welders that could be used as a TIG set. Most were not dedicated TIG welders, but stick style welders that could be used with a TIG torch. This kind of setup is what's known as a scratch start set. which means that to initiate the arc, you need to touch the electrode to the work piece. This is fine and not really an issue, but for a few dollars more you can get a HT start. This style of welder initiates the arc using a High Tension spark which is initiated when you press the button on the torch / pedal which is what I'm used to with my other unit.

Looking for HT start welders puts you into the dedicated TIG welder territory, which also means you can get units with adjustable pre and post flow. What this does is start / stop the gas flow before and after the arc. This means that gas is applied before the arc is struck and also supplied for a time after the arc is extinguished which ensures that the arc is always shielded and helps minimise inclusion (weld contamination). Often with scratch start sets there is no gas control at all and the gas has to be controlled manually. Which means opening a valve before you weld and then remembering to shut it off afterwards as well.

The good thing about a dedicated TIG set is that they usually integrate the gas control and also include the TIG torch.

The unit I decided on was a Giantz 220amp unit which was just shy of $200 delivered. This particular unit had a 60% duty cycle at 180amps which is enough to weld 6mm. The until will also weld up to 220amps but at that kind of power the duty cycle drops to 40%. It will happily weld thinner materials all day long which makes it perfect for things like 1mm body panels. It also included gas post flow control. The pre-flow is however unfortunately pre-set but no real biggie.

https://www.ebay.com.au/itm/284723697842

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The unit arrived pretty quickly and I set it up for a quick test. The results were pretty good. the arc is nice and stable and it has plenty of power. The unit itself is very lightweight, in fact ironically the gun cable is heavier than the actual welder.

A quick bead on some 1mm. Not the best weld in the world but okay for out of the box

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Same again but on 5mm

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I haven't done a long term test on this but from what I have seen so far the results are good. The unit is light weight, The torch head is not great but replacement heads are really cheap. I ordered a more modern style with integrated trigger switch but have not fitted that yet. It also does not come with a gas regulator so factor one of those in with your purchase along with some hose. These are the items I bought for mine

https://www.ebay.com.au/itm/403564491002

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The torch upgrade is of course a personal preference. there's nothing wrong with the one supplied with the welder, they work fine, but for an extra $26 you can get a really nice ergonomic setup that's a lot more comfortable to use

https://www.ebay.com.au/itm/194753004780

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The regular is necessary. I prefer the flow style regulators which incorporate the flow gauge as you get a good visual indication of the flow. Needle style gauges are great but I personally find that it's much easier to read the floating ball. This particular one is offensively cheap which I can only put down to being produced in surplus for covid (as oxygen regulators). They fit the standard argon / MIG gas bottles which is the main thing.

A quick note on welding gasses...

You do not need to use argon for steel, you can happily use MIG welders(like this) for TIG welding. It is generally the metal that you are welding the dictates the gas type and NOT the welding process as most people assume. MIG GAs / Argo shield will work fine for TIG welding steel.

In summary I'm pretty happy with the welder, the tests that I carried out were good, the welder behaved as good as my big Miller AC/DC unit. Weld power control is good with 1mm being pretty easy to handle. I did not try it on thinner material but I suspect that it work work well. There is unfortunately no foot control but for a portable unit that should not be a deal breaker.