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mig v tig
theconrodkid - 20/12/02 at 07:06 PM

ive allready got a mig that i use for common welding jobs ive been offered a bigger and better one, do i buy it or get a tig?
what are the running costs of a tig compared to mig
i do mainly car repairs and shopping trolleys etc oh and build the ocasional locost chassis.your thoughts please.


interestedparty - 20/12/02 at 07:16 PM

I can't do TIG myself but I've been told that although excellent for tricky stuff, especially ally and stainless, it is slow

John


Wadders - 20/12/02 at 09:42 PM

TIG is slow because the filler wire is added to the weld pool manually i.e by hand.
Really TIG is like oxy/acetylene gas welding only with a much more controllable heat source.
Most pro's using TIG to weld ally will have spent in excess of 10k on their equipement. so for general welding duties i reckon a decent MIG set should surfice, the highest amperage set you can run with the mains power you have available

Hope this helps

Al


theconrodkid - 20/12/02 at 10:11 PM

thanks peeps only tried it once long time ago so cant remember how fast or slow it was,dont regard oxy as slow though.


theconrodkid - 20/12/02 at 10:12 PM

as i allready have an arc welder as well can i put the tig kit on that?


paulf - 20/12/02 at 10:33 PM

Theretically it is possible to use a tig torch with an arc set but having tried it i would say the answer is no. I tried a tig torch atttached to my mig set to get a dc supply and then scratch started the arc, but doing so damages the tungsten before you even start welding. Really a high frequency unit is needed to start the arc and maintain it if using AC for ally welding.I did know someone who mackled a set up with an old hf unit rescued from a scrap welder and various inductors etc to give a good current control.
It is going to be a future project of mine to do something similiar but until then i will just use the tig at work and let them supply the gas etc.
Paul.

quote:
Originally posted by theconrodkid
as i allready have an arc welder as well can i put the tig kit on that?


theconrodkid - 21/12/02 at 04:16 PM

ah well another plan bites the dust


David Jenkins - 21/12/02 at 06:08 PM

Just remember that operating a TIG set is like tapping your head, rubbing your stomach, whistling Dixie and juggling a chain saw, all at the same time... i.e. good co-ordination is an asset!

Assuming you're right-handed, your right hand is holding the torch while your brain is trying to maintain the arc length, move across the work at the right speed and maintain the right angles. Your left hand is holding the filler wire and feeding it in as and when required, while your brain is working out the state of the weld pool. One foot is working the pedal that controls the current and gas. The other foot is working the bass drum.

OK - I lied about the bass drum.

On top of this, you will previously have spent a while scratching your head about the settings for current ramp-up, ramp-down, max. current, etc.

Oh - and while you're welding, you may get little electric shocks through your left hand, every time the arc initiation fires.

Apart from all this, it's great fun and gives great results!

rgds,

David


theconrodkid - 22/12/02 at 12:35 AM

as you put it that way David ill stick to my mig


Viper - 22/12/02 at 02:58 AM

If you are using a pedal you don't need to worry about slope up or down coz that's what your foot is doing...and its not that hard, if i can do it anyone can


Alan B - 22/12/02 at 01:28 PM

I'd say it's about 10 times more difficult than MIG...doesn't mean it's impossible, obviously, just a lot harder.

To me a good TIG welder is a REAL welder.

That doesn't include me BTW, I've MIG and stick welded for over 20 years, but can barely run a TIG bead. (although I've only had a couple of hours practice) I can feel that I will be able to master it, but I'll repeat IMO it is a lot more difficult.

Funny thing is I've designed a lot of automated welding equipment, including TIG, but you often rely the customers expertise for the final set-up.

Viper, if you found it pretty easy, then I suggest you are fairly well co-ordinated to start with or have done gas welding previously.

Again, just IMO....I may just be a clumsy klutz...


Alan B - 22/12/02 at 01:46 PM

Just to show how sad I am I even photographed my first TIG attempt..

In my archive as first TIG.

It was after about 20 minutes practice on 16g stainless. Crap obviously, but it gave me the feeling I could learn eventually.

Contrast with the picture auto TIG which I did on a machine I designed.


Viper - 22/12/02 at 08:32 PM

TIG is easier than gas, especialy on alli...


kingr - 23/12/02 at 12:18 AM

Alan - How does your auto tig produce those lovely rippled welds? I heard that with tig that effect is produced by doing small circles with the filler, but I was also shown pulsed mig by the guy that taught me that produced a very similar effect, and I would suspect that it may be easier to use pulsed welding when automated.

kingr


Alan B - 23/12/02 at 03:01 AM

2 words

pulsed autogenous

3 more

Happy Christmas everyone!


gjn200 - 23/12/02 at 12:48 PM

Tig is easy, just so damn slow. I have always used it on s/steel at work, plus after you've done the weld and it looks shite, you can go over it again and make a nice fish tail effect. (not that I would ever do something so bodgy as that)

Graham


David Jenkins - 23/12/02 at 07:58 PM

To be honest, TIG isn't hard as I made out, once you've learnt it.

When you start, you wonder how the hell you're going to get it to work - gluing tungstens to the weld pool (it's amazing how blobby they get!), blowing holes through, etc.

It is satisfying when it works, but it is SLOW!

As someone else said - it's like oxy welding, without the excess heat from the flame cooking everything around.

cheers (and Merry Christmas!)

David


kingr - 28/12/02 at 12:52 AM

I'd still love to be able to tig weld, if only the gear were a lot cheaper, I know I'd want AC/DC with HF start, and you're looking well into the grands for that kind of thing . Ah well, one day maybe.

The thought of fabricating my own exhaust from stainless and with a titanium can is very enticing. Add to that how attractive the thought of being able to work with ali as well as steel, and how nice the welds look when done properly......

Ah, if only I had all the tools I want, and a nice, clean, bright workshop to keep them in......

It's almost enough to make me start playing the national lottery!!

Kingr


theconrodkid - 10/1/03 at 08:30 PM

had a play with a tig at the show today,i did good!,looks like the one in screwfix catalouge only a bit more money so i think ill but one anyhow