tig from mig??

[lovelectricity]

i have asked in two sections as its a crossover, why cant you get a tig gun, slap on a euro connector for power/gas. turn the wire feed to zero. add a foot pedal/ switch to turn it on and run pure argon? is it possable, what have i missed ok no hf start but cheap. is this idea half baked?

 

[irondarren]

mig works on voltage as opposed to amperage. amperage on mig is controlled by the speed of the wire. easy to get an arc welder to run as a tig, because amperages etc are very similar, mig works on a slightly different way

 

[lovelectricity]

sorry ive messed things right up i deleted wrong one, ok a pickhill giant 220, external rectifier, bits for gas etc what do you rekon is is possible, ok no hf but oh well

 

[matt1978]

Ref, the making a mig into tig, you wouldn't be able to do it for a couple of reasons, As Shenion said, you need CC for Tig, where as a stepped voltage transformer machine like I imagine you have is CV only and the OCV (Open circuit Voltage) would be about 30 Volts, where in tig, you only need 10v or so, so it would wreck the Tungsten on ignition. 2nd point is that your mig euro fitting is Plus polarity and you need your tig torch to be on minus or again, you would obliterate the tungsten. Add onto this and you wouldn't have anyway of controling the current (amps).

Get yourself a small dc tig inverter!

 

[malcolm]

sorry ive messed things right up i deleted wrong one

Hope you've found the error of your ways there. Double posting tends to end in confusion.

Pickhill is an arc welder is it not? ARC voltage works the same way as TIC There are TIG adapter boxes available for arc welders.

 

[lovelectricity]

oh is all going pear shaped i cant keep track of the two posts. gonna keep lookin at this one sounds more hopfull.

 

[lovelectricity]

cheers malc learn that one the hard way. wont do that again. ok then yep pickhill is an ac arc welder volts= 50 or 80, amps= 20-220

 

[matt1978]

What sort of stuff do you weld up lovelectricty?

 

[lovelectricity]

ok i do steel with current set up, stainless with arc and stainless rods, would like to do aluminium and stainless with tig for no reason apart from it will be helpfull and i like to make things my brain hurt from double post. bloody hell a hell of my own making!!

 

[oddball90]

For ali welding you will need an AC/DC tig welder.

 

[shenion]

You can do Al with MIG and pure argon with a decent MIG. Not ideal but it works.

 

[lovelectricity]

do u mean rectify to output from the stick? sorry shenion its gone mad. i mean tig from well it now seems to be the arc set. didnt expect that!!

 

[shenion]

You can add a rectifier. You will also need to add a reactor for best results.

There are HF start units available, I see several on ebay.

 

[oddball90]

Lovelectricity you can weld aluminium with a mig welder but it is not easy on thin material, also needs to be a good mig machine not a hobby one. For Tig welding aluminium you need a AC tig, this is neede to help with oxidisation of ali. When the polarity goes negative it cleans the oxidisation from off the surface of the weld.
Don

 

[matt1978]

Yeah as Oddball said, if you wanna Tig weld Aluminium you need AC tig set. The plus (positive) pole, cleans the oxide layer off, and the minus (negative) pole gives you your welding value (penetration), on most decent AC tig welders you get a AC Balence knob, so you can choose more + for greater cleaning effect, but this will give you a big ball on the tip of the tungsten and not as much penetration, or - pole for greater penetration but this is not good when welding "dirty" aluminium. Most welders come pre-set at 35% + and 75%-

You can weld Alu with DC tig but the tig torch/tungsten has to be + pole, which means 2/3 of the heat is at the tungsten so you need a really thick tungsten 6mm or so to cope with this extra heat.

 

[lovelectricity]

ah got it. no mines not hobby its a boc machine. it could do ali suppose. right stainless needs dc and ali needs ac am i correct on that? stainless needs a rectifier ali dont. reactor/choke, large cacacitor to try and keep the voltage stable when doin stainless. am i getting it or am i way off? (this ac welder is the same as an oxford and has a f**kin great choke already in it)

 

[matt1978]

Nah, Alu needs AC on Tig only. On Mig welding you mig weld on DC positive, thats what your mig torch is, DC+, so you got 2/3 of the heat at the electrode (Your mig wire) and 1/3 of the heat at your work piece (Via the earth cable) so you can mig weld Alu on DC, using your conventional BOC welder. Only problem with mig welding Alu is mainly feeding the wire. You idealy need 4 roll drive and fairly short torch. Also for thin material its much much better to have a Pulsed mig machine as you can mig weld Alu and Stainless with a Tig cosmetic appearnce. Also using a bigger dia wire such a 1.2mm, so its much easier too feed.

 

[shenion]

If the AC welder has a choke, put the rectifier before the choke.

 

[lovelectricity]

gettin another welder thats broke tommorrow will use this as the basis of a tig its all good fun but all the add on units seem to want dc. i could get this from the mig.

 

[shenion]

Add-ons are for AC/DC.

You can't use the MIG supply as it is CV instead of CC that is used by TIG.