TIG or MIG welder

[birchy]

I've just moved into a workshop with 240 & 3 phase supply

In that case, it might be worth looking for a used industrial machine. They're usually fairly cheap because not many people will have 3 phase. Have you got a Saracen near you? They're a local company who supply workshop equipment and often have reconditioned/serviced machines they've taken as part-ex.

[m_c]

If you have 3 phase, get a 3 phase welder!
The 3 phase means you get a far smoother DC supply, which translates to smoother welding, and as birchy says, because very few people have 3 phase, 3 phase welders go for peanuts secondhand.

[corkcnc]

I think if it's a case of one or the other I'd go with the TIG. As been mentioned, TIG will get you out of a lot of tight spots in mild steel, ally and ss so it's pretty versatile. If you have a lot of mild steel welding though in terms of a large frame then MIG is twice as fast and simple once you get your set up and angles right.
However if it's an outside job on a windy day, welding gate posts etc.. my ancient Pickhill Bantam kicks ass everytime. (Once you have someone to reset the trip after the inrush into the coils knock the mcb).
Still for a lad with a workshop or garage I'd still go for TIG. The control you can achieve lends it to many applications. Even putting holes in work hardened stainless when someone calls over after trying to drill a hole in ss with high speed on their battery powered drill....(clamp a heavy washer around the hole first to limit the burn.)
Definitly agree about gas bottle rental. Don't dream of taking out a rental contract on your bottle, even the small ones. Pick on up second hand is your best bet.

[birchy]

I'd have to agree that Mig will do most jobs but there are occasions when TIG and ARC are more suitable. If you have a workshop and 3-phase, then I'm assuming you're setting up something a bit more professional than a garden shed workshop? If so, get a 3-phase MIG welder and a small inverter TIG/ARC. The latter will often be combined into one set as they're almost identical electrically. Inverter driven arc welders are an absolute joy to use. I bought one of these last year for £300. It's been better than expected, however it drinks Argon faster than I can drink scrumpy!

SIP (S.I.P) 05266 Weldmate Welder P178 (160amp) HF Tig/MMA/Invert Welding | eBay

[IanS1]

Thanks for all your advice folks. I'll have a good look into a 3 phase and good look into MIG in general.