new tig

[grunty]

just bought a tig to have a play with before I spend serious money on somthing I can't get the hang of.
I have some aroshield light, can i start with that for a practise, will it be ok for ally?
How thick will 140amps weld?
ta muchly
Al

 

[shenion]

That is a DC TIG, not intended for Aluminum. Supposedly, DC will work, but you need to clean the alum completely. AC is preferred for alum welding.

You need 100% argon for TIG. Any other mix will contaminate the tungsten. You can test it with argoshield, but the electrode will degrade.

140A should do about 1/8"

 

[snowcat]

Oh no dont try and D/C ally its sooo hard to keep the temp zones. Just get some pureshield argon and have ago with some standard LCMS.

 

[Graham]

Scratch start

I was spoiled by years of using a Miller Goldstar 350A set with all bells and whistles. I wa looking at getting a little inverter 5-80A and they say they have things like 'hot start', 'anti stick', and 'scratch start'.
I am sure that scratch start speaks for itself but dont you loose the end of the tungsten each time? how do you stop, just pull away and oxidize the new weld?
Yes I have been spoiled.

 

[shenion]

Many have reduced current when starting and goes to set current when lifted. So there is not a big surge when using scratch start.

Stopping would be via the footpedal or button on torch.

 

[irondarren]

Cant beat a nice HF start unit, I bought an inverter fusion php 200, cost me about £750 inc vat + i had to buy a parweld torch which was about £60 i think. Cracking little DC machine, plus it does 180amps MMA, which is fine on 4mm rods, even does 7018 rods nice.

Shenion you sure 140amps does 1/8 plate, I used to do much thicker than that on my EWM pico 140, used to be able to do 1/4 plate nice on the 140.

 

[shenion]

I used Millers TIG calculator and it shows 115-135 for 1/8" butt weld.

Others have said the amps are a bit high. I imagine you can go slower and use less amps.

 

[irondarren]

I guess a lot of it is down to travel speed, the faster you go the more amps required

 

[Drains]

THE "hot start" and "anti stick" relate to MMA.

You don't have to lose the tungsten tip each time with scratch start, but theres a good chance you will. There's an acquired skill to scratching.

You can use a carbon pad to start with a scratch machine. I knocked up a wee holder for an old carbon brush from a drill. You get the arc going with that, then take it away and pick up the filler wire.

Shenion's talking about Lift tig - low current until the machine detects a loss of continuity when you lift off, then it puts in the welding current, so less chance of tungsten loss or contamination.

 

[Graham]

TOP tig

For my Saturday job I use a little inverter 160A machine by CEA (or CAE? nah CEA), called a TOP mig.
It has HF start, pre-set ramp up and ramp down as well as post flow gas purge. Just has a foot switch for on/off. It goes down below 5A which is a real plus for light stainless.
Its a great little machine but I do miss the Miller Goldstar.
I bet the TOP was over £1K too.

I cant see any remote switch on these little inverter tig's.
I use 5%Hydrogen in Ar as the work is very light stainless.

 

[irondarren]

I really do need a foot pedle for my Inverter fusion TIG, saves so much messing around, espcially when it comes to the edge of the work piece where you can back off the power and not burn the corner off

 

[DIY Welding]

Which model is it I have some s/hand pedals in stock

 

[Weldingartisan]

Which model is it I have some s/hand pedals in stock

Not got one one for a Kemppi Mastertig by any chance?