Thread: MIG /TIG whats the difference?

Originally Posted by HangOver

thanks for the advice
I bought a mig from fleabay it should be here early next week :-)

the amps wasn't high, about 140amps but the price was cheap.
Can't wait to play :-)

Steve all i can say mate is ya get what ya pay for these days

Mate for what you want to do a mig will be fine tho personaly i wouldent use the gasless wire it is pure cr@p u will see id say cause most of the cheapys come with a roll ....

Either bite the bullet and pay bottle rental (which i do)or use the throw aways and use lw1 mig wire .9mm in dia should be ok with the unit you have mentioned the gas bottles will come down to how often you use it as mine gets used at least once a week id rather pay the 130 a year rental and 70 per fill than be caught without gas .....

Also the mig you have purchased may be used on different metals like steel,stainless,alloy's and some brass and bronze tho you will need the same type of wire for the meterial you wish to weld also different metals require different gas for instance steel uses a mix of argon,oxygen and carbon dioxide BOC gases refer to this as argo shield light or heavy then for alloy you can use straight argon or now you can get allishield which is mainly argon with another gass i cant recall its name but i use straight argon and it works fine then stainless you can get stainshield tho straight argon will do the job well enough .....

As for the difference between mig and tig welders what the others have said is right tho a tig welder comes in a few different vairiants you can have a straight DC tig welder or you can get the dearer AC/DC tig welder both these machiens come with either Pulse mode and HF mode or both or nither it all comes down to price and what sorta welding you need to do with em the HF is a high frequency zap so to speak that can be set to provide easyer starting of the weld by throwing a spark from the end of the tungsten electrode to the job this is a must for alloy welding with a tig and to do alloy you need the dearer AC/DC unit as alloy requires AC current to weld it .....

The standard type DC tig (which i have) is great for doing steel and stainless tho wont do alloy i have a mig for that tho the DC tig is great for doing both light and heavy work mine is a 140 amp transtig caddy great compact machiene and it can also be used as a stick electrode welder which requires the stick hand peice and the polarity must be changed from tig to stick stick requires the earth to go to the neg terminal and the electrode to the pos terminal DC tig welding is reversed with the earth on the pos terminal and the torch/electrode on the neg terminal ....

For doing weld jobs on veheicles i mostly use my tig as there is no spatter to worry about and the welds dont need to be cleaned up and the tig is great for doing welds upside down or in tight spots like inside diff housings and the like also tig welds are much stronger and done proper are air tight i can weld to presure specs tho ive been doing this for many years as im a sheetmetal worker by trade and i use to work in the mining repair industry and welds had to be pressure tested up to 1500 kpa for some applications ...

Mig welding is also just as good for general repair and manufacture and for use on veheicals tho i tend to only use mine on alloy or jobs were the parts to be welded have been removed from the veh and can be done on the work bench like when i did my brothers (cal415) rear maxi and diff guard i had the housing on the bench and did all the welds with the mig tho i used my tig to repair the back of the pumkin where the cross shaft and the side gears air conditioned the diff housing when he broke the std diff center whilst snatching a broken pootrol .....

So there you have some more info to ponder weather it be relivant or not i think i have given a fairly broad explanation of some of the stuff i know and could go on for pages and bore you all as theres so many vairyants of welding tho this chapter has explaind the bascis and may be usefull to some body

Cheers

Chris

thanks for that I didn't know you had to use different wires and gasses for different metals

I am a frim believer of "buy cheap; buy twice" and I was dubious about it being so cheap but I think if I can get one or two welding jobs done on it, it will have paid for itself any more will be a bonus

A few weeks ago I got a welding job done on an exhaust it cost nearly $100
This unit cost about $275 to the door.

Once I have the the jobs I want on the RRC I will probably be used about once a year!

thanks again