I tried out my Old Telwin vs. New Lincoln machines today

[alexGS]

Hello - at last today, I was able to fire up both my old MIG and my new MIG - I wanted to try the old again first, just to ensure I was being fair in my assessment of the new

Old machine first - it's a 130A Telwin, only ever a cheap machine, bought about 16 years ago. The gas regulator wasn't even working - needle just went straight to maximum regardless of the tap setting - so I borrowed the regulator that was supplied with the new machine.

There are two rocker switches - you can have 1 or 2, and MIN or MAX. There is a wire feed knob, which I set on about 3 out of 10.

As you can see, results on 1 and MIN are pretty dreadful. The machine makes an intermittent humming noise as the arc stops and starts.

Results on 2 and MIN are better, with a steady arc and better penetration, but I managed to blow two holes in the vertical-up butt-weld of the 0.9mm steel sheet (clamped in the vice).

1 and MAX is more powerful again and produced a lovely smooth bead, but I didn't bother trying the butt weld at this setting, as I knew it would blow straight through (the test bead shown was on the flat with a backing plate).


Now for the new machine...

 

[alexGS]

The new machine is a Lincoln Powercraft 180i, an inverter machine with synergic function and inductance control. Of course it's made in China, but the quality of build is leagues ahead of the old Telwin, despite costing about the same. Well, a tad more - $1299 against $899 16 years ago. Cast alloy wire feed mechanism, a Euro torch connector with a solid-feeling 'cord' on the supplied torch, a much-better earth clamp with the copper bridging inside - even the gas hose fittings, screwed-on, are much better quality than what passed as acceptable in 1999.

So what can it do? Well, a lot more than I can do with it, that's for sure!

I tried the Synergic mode first and was surprised to get no stable arc out of it at all, at the lowest voltage setting (with current and wire feed automatically controlled).
You can see the first three beads (on flat plate with backing) on the left of the picture.
Increasing the voltage to 16V produced a useful result, and manually increasing the current from 38A to 55A didn't seem to make any difference at all, which was odd.

Next I turned off the Synergic mode, which eliminates the current control knob and replaces it with a wire feed speed control knob (i.e. the digital knob stays the same but its function changes - welcome to the microcontroller age). It's also worth mentioning that the knobs have 'steps' but no end stops - they spin endlessly, which is nice.

Stepping the voltage up to 20V produced a nice smooth fat bead that gave a good deal of distortion.
16V seemed about right, and then it was a matter of turning down the wire feed progressively to try and reduce the 'build' and improve the penetration.

The vertical-up butt-weld with the 0.9mm steel plate was an interesting experience. 16V and a wire feed speed of 2 gave a nice steady and controllable arc with quite a bit of build and no risk of blowing holes. This seems far improved on what the Telwin could do. The interesting part was that the weld had a hissing sound, rather than the usual crackling.

Even a small adjustment, stepping the voltage down to 14V and the wire feed down by what I thought was a proportional amount (to 1.5) resulted in a popping sound and the feel of the gun being pushed away from the surface (i.e. wire feed speed too high!)

I spent the next 20 minutes cutting up ten little squares and blowing holes in them, trying to replicate the results of 16V/WFS2. It didn't help that it was now dark and very difficult to see anything in my workshop, even with a head torch strapped on the helmet, etc. The different 15A power socket (fitted onto the extension lead, for the new welder) means that I can't use a double adaptor for the lights etc.

There's still the inductance control to experiment with! Heheh

 

[alexGS]

One more picture, showing the result from the old transformer machine (left) and new inverter machine (right) at their practical minimum settings...

 

[alexGS]

And the back, which shows little penetration of either, but at least the new machine was a more even result.

Cheers for reading... Comments are welcome
I know I have a long way to go in my quest, but the aim is to weld reliably in a vertical position without a backing, since that's what I have to do in the repair of my FIAT 850 bodyshell.

Mainly my aim here was to compare an old machine against a new machine in equal hands, to see whether there was a big difference and perhaps help others decide whether to upgrade. I should also have mentioned that I'm using 0.6mm CIGWELD wire, with 75/25% Argon/CO2 mix.

-Alex

 

[Chris Stevens]

You might get better results with .8mm wire...........

 

[alexGS]

You might get better results with .8mm wire...........

Oh OK, thanks for the advice I'll try it.

What's the 0.6mm wire for - I thought this would be a case for using the thinnest wire?

-Alex

 

[Chris Stevens]

I did vehicle welding professionally for 4 years, and cant say I found a use for .6mm wire in that time. Guess its better for some jobs, but personally would never use it to repair a body shell.

 

[octo0072000]

Some people swear by 0.6mm for thin metal.

I'm not one of them... Tried it, don't get on with it. 0.8+ for me.

same for me 0.8m used 0.6m can't get on with it

 

[alexGS]

I switched to 0.6mm a couple of years back - the benefit I noticed was the increased wire feed speed, which was more consistent than slower speed on the old machine. I also felt that smaller wire gave a more stable arc at the minimum current setting, but there might have been other variables (e.g. material cleanliness). Of course, the new machine has better wire feed control, which makes it worth me trying the 0.8 again. Thanks for the advice.


So - what's been the general experience of using IGBT inverter machines compared to older transformer types, especially working with thin (less than 1mm) steel sheet?

I searched the Internet a few months back and found most discussions were comparing the size and weight of the machines, and the price. I was more interested to know whether an inverter MIG 'turns down' better than a transformer type, in the way that an inverter microwave oven or an inverter heat pump (reverse cycle air conditioner) turns down to lower power where conventional types cannot.

My DC TIG is an inverter and turns down beautifully - it can run a bead less than 3mm wide - so does an inverter MIG bring the same advantage?

I thought synergic control would work better than it seems to, but I guess that's a machine-specific discussion which belongs in a different forum.

The main point here is whether an inverter MIG brings sufficient advantage to be worth replacing an old transformer MIG. Perhaps a better demonstration would help, too

-Alex

 

[Chris Stevens]

My old Kemppi transformer welds .5mm exhausts no problem, and I certainly wont be changing it for an inverter anytime soon.

 

[premmington]

same for me 0.8m used 0.6m can't get on with it

I own a vehicle repair garage... There is always a debate about 0.8mm and 0.6mm wire use.

I have two Mig welders threaded up.

1. Miller with 0.6mm A18 wire and pure Co2.
2. Kemppi with 0.8mm A18 wire and Argon 5% Co2 mix.

0.6mm wire in pure Co2 does give you a less "wetted out" weld bead with a higher profile. Which is what I want sometimes for panel work.

I am finding I am Tig brazing more and more of late for panel repairs.