Thread: MIGs for car bodywork - do any go lower than 30A?

Originally Posted by JNorton

Do you really, REALLY need a spot timer?

Originally Posted by Jarh73

I don't think you NEED a spot timer.

Damn you guys are persuasive.

I was thinking spot timer because I need to replace at least a couple of panels completely, with ones from a parts car (drill out the 20-ish spot welds, and plug weld onto project car).

But you're right - spot timer isn't necessary. I guess if I wanted to I could use an audio cue to govern spot time for consistency (e.g. lead-in count and 3.5s beep in headphones - easy to create for an ipod or similar) - but practise and experience are probably good enough.

So now I'm wavering back to the inverter devices..

Originally Posted by LordBug

Why not get one of those multifunction units? The Unimig 190 inverter does MIG & TIG, so you'd have access to both, and that's a $1,300 package from a place local to me in Perth.

Originally Posted by JNorton

That way, you could also look again at things like:

Tokentools inverter MIG TIG and ARC welder - MIG welding and TIG welding and ARC welding

The Unimig 190 is on my list already, along with the Cigweld 175i, and I'd looked at the Tokentools $800 one after seeing the "Chinese TIG" thread here as well as a few other references.

I guess more reading is the order of the day - then a visit to check out some in the flesh. One that weighs only 20kg is certainly appealing - would be able to chuck it in the boot and take it to mates' houses too... not to mention the tools to practise TIG.

How important is it to have separate wire speed and current controls? I see the inverter ones combine functions to a single dial - I've certainly had to adjust both a fair bit when setting up to weld in the past.

The more input people are giving me, the more I'm realising I really need to do a short practical course in MIG (and TIG possibly) process to get the most out of welding.

Spend an evening or two here:

Welding Tips and Tricks - TIG, MIG, Stick and a pantload of other info

Very highly regarded site that will answer many of your questions

Regarding the spot timer. A work around with a TIG would be to simply set it on a pulse setting of say 4 pulses/sec, then count how many pulses you put into each weld. After you'd done about 3 or 4 welds I reckon timing it would be completely redundant as you'd know instinctively how long each weld takes.

For extracting broken bolts, the TIG will work just fine. Clean up the whole as much as possible (e.g. grease, etc.), stick the tungsten out so you can get it right down in the hole close to the bolt. Only disadvantage is that you also have to manoeuvre your filler rod in there too to start building up a lug. on the other hand, the advantage with TIG is that you have heaps more control for small bolts so you don't accidently weld the broken bolt to the edges of the hole.

Cheers

- Mick

Originally Posted by homemechanic

How important is it to have separate wire speed and current controls? I see the inverter ones combine functions to a single dial

The amp function of the dial is only in effect when it's switched to stick (and I assume TIG) mode. In MIG mode the dial only controls wire speed.

What I'd like to know is how useable these DC machines are for TIG? I see references to "scratch start" but there seems little info on the net on how this works as opposed to AC TIG.

Originally Posted by RustyArc

What I'd like to know is how useable these DC machines are for TIG? I see references to "scratch start" but there seems little info on the net on how this works as opposed to AC TIG.

The high frequency start allows the arc to initiate without touching the tungsten to the work. As I understand it, the HF is also high voltage, so the voltage helps to bridge the air gap and once ionisation has started, the main current (at a far lower voltage) can successfully bridge the gap following the ion trail.

If you haven't got HF then you have to scratch start which risks contamination of the weld. Lift arc helps in this case. The older AC welders particularly (sine wave) had a long period with little current flowing to maintain a steady arc during each cycle (i.e. when switching between EN and EP), so HF stabilisation is needed to keep the arc live.

Apparently HF is a 'nice to have', but personally I reckon it's one of the things that makes TIG welding a joy.

Cheers

- Mick

Originally Posted by homemechanic

How important is it to have separate wire speed and current controls? I see the inverter ones combine functions to a single dial -

If you are talking about the Token tools 3 in 1 machine, that's not correct.

The link to the Token tools 200 Inverter IGBT machine shows a Wire feed / amperage control on the right side and a Voltage control /heat input on the left side.

The voltage knob ( on the left hand side) has absolute adjustment quite different from the old transformer migs in that they were adjusted by a series of steps off the transformer .The rotary stepped switch depending on the number of steps gave a close adjustment.


The infinite adjustment should be a joy to use.

I had initially followed the link to verify the above, but find I am really impressed with the fit out and quality of the machine

This machine has had some real effort put into its design if you care to take a close look. The way the wire drive cover swings out of the way and the ball detent closures are things you don't see on dearer machines. The
Alloy wire drive frame also bespeaks its quality.

This is a serious value for money machine. Given that the opposition machines (also Chinese) at this level are left in the dust by this machine. I see a potential buyer will have a better pathway to quick rectification of problems in the event there are any, if you check out the warranty and after sales service.

Thats my 2c worth.
I have no connection with Token Tools in any way if any one was wondering.

Grahame

Cigweld 195 with remote feed, as Grahame recommended :

Cig Mig Welder | eBay

Says he can freight.


Also, here's a video showing the tack weld MIG technique for thin sheet steel:

Welding Video - Mig Welding a Patch

Hi,
Don,t let the grime on the machine throw you off.
The last schoool I was at had one of these units since new and still have it.

I wonder how many of these other new fangle dangle machines could survive the rigours of a high school engineering shop for over 20 years?

If you are still talking aluminium you could still throw in a Lincoln spool gun -around $350 and still come out on top.

Grahame

Originally Posted by WelderMick

Apparently HF is a 'nice to have', but personally I reckon it's one of the things that makes TIG welding a joy.

I really have to agree. Whilt my TIG experience is half an hour in total with only an HF machine, I can very easily see myself being frustrated with a scratch start (Having just done a bit of reading on tips and tricks relating to it).

$315 that Transmig went for!

I'd consider looking at 2nd hand models aswell.....Your price range is more than double what i had when i was buying my first MIG.

I picked up a 2nd hand cigweld transmig 195 for $550! Ive welded very thin sheet metal and thicker 8-10mm mild steel. Ive never used the spot weld timer option, once the settings are right you just power on, with no blow outs.

Only problem is that its a 15amp plug and from experience, running it on a 10amp plug is a really STUPID idea. So the money you save will most likely be spent on upgrading the shed circuts

For your price range i think you'll be able to pick up a really good MIG, plenty of great 2nd hand MIGS out there and with the money saved you can get some gas and steel to play with

Cheers

UglyDan

Originally Posted by UglyDan

I'd consider looking at 2nd hand models aswell.....Your price range is more than double what i had when i was buying my first MIG.

I picked up a 2nd hand cigweld transmig 195 for $550! Ive welded very thin sheet metal and thicker 8-10mm mild steel. Ive never used the spot weld timer option, once the settings are right you just power on, with no blow outs.

Only problem is that its a 15amp plug and from experience, running it on a 10amp plug is a really STUPID idea. So the money you save will most likely be spent on upgrading the shed circuts

For your price range i think you'll be able to pick up a really good MIG, plenty of great 2nd hand MIGS out there and with the money saved you can get some gas and steel to play with

Cheers

UglyDan

After reading the Welding Tips and Tricks site and watching many videos once the kids were asleep, I'm thinking TIG looks like a lot of fun and a lot of use.. but I'm not on the market for two welders just yet

I've been nosing around and there's a used Transmig 200 up for sale locally (not on ebay). 15A plug isn't an issue - I already have a couple of 15A sockets in the garage (needed one for the compressor). If I can't get a good bargain locally on a quality used MIG in the next month I'll look at using my whole budget on an inverter MIG with lift-start TIG; I can see good use for TIG on steel and stainless - and it does look like fun.

Thanks all for your input - its made me do more concrete thinking and reading, and I now have a plan of attack (and an HF-start AC TIG welder to add to my "tools I'd like to own" list! ).

I'll update when I get my hands on a welder and gas bottle!

There seems to be something of a fixation about spool guns for Aluminium - they are not necessary in most cases, (12 years in the aluminium welding industry and I haven't used one yet).
I know that salespeople will promote the fact that you can swap over and mig weld Aluminium, and you can. But it is a very different beast to either carbon or stainless steel, (as a generalisation migs are at their best with new, clean material on jobs that do not need to be leakproof).
The chinese multi process machines look attractive but my experience has been that you either get a good one or a dog. Stay well away from any machine containing a plasma cutter.
You will be amazed at what a good operator can achieve with a well set up, good quality mig running .9 wire. Remember that the smaller the wire the more potential feed problems that you will have. Thin materials are more sensitive to poor inductance settings in a CV powerplant, (MIG is CV, TIG and Stick are CC). This alone would be enough to make me cross unimig off my list in the first instance.
HF start is very nice on a DC tig, but not essential, constant HF is essential in an AC Tig, (you won't finds one without it). Pulse too is a nice luxury but not essential.
The notion that mig's are "point and pull" always concerns me, anyone can squirt metal, but it takes an operator to weld efficiently.
TIG is probably the "Rolls Royce" of processes, but requires a correspondingly higher degree of skill and is far slower than Mig or Stick welding.
Your best bet is to get some sheetmetal and try the machines on your list at the dealership, you will then have an accurate picture of their characteristics.
Good luck.

This listing might interest you or anyone else looking for a CIG 3-phaser:

CIG trans mig 300 & 250, plus 3 wire feeds. 3 phase. | eBay