TIG Welding questions before i bite the bullet

[Richard.]

would i NEED one from the get go, or better to just have a bash get used to it and then intoduce a foot pedal later

Well I use my pedal about the same amount of time as I use the torch switch.
Sitting at a bench with the part laid out you can't beat a pedal for this but unfortunately life's not that kind and when the job isn't at the bench but requires you on your knees welding above your head you are gonna have to make do with the switch so it's good you learn to control the pool on a fixed current. Id see if they will do a good deal on a pedal for you with the unit. If not buy it later.

 

[blenkie1]

Might get a flood damaged one from tec arc! Funny no one has mentioned duty cycles in all this. Will it be important to you?

 

[Burdekin]

It does

My DC machine is one of them but I'm not a fan. Maybe the more expensive ac/dc machine is better.

 

[NickyEng]

Every days a school day I stand corrected

Not in anyway arguing with you rich but quote below on conductivity from Lincolns website says I am correct from a certain point of view

Many inexperienced aluminum welders use preheat as a crutch. Since equipment for welding aluminum needs to operate at higher capacities. Aluminum has a low melting point -- 1200° F compared to 2600° F to 2700° F for steel. Because of this low melting point, many operators think they only need light duty equipment to weld the aluminum. But, the thermal conductivity of aluminum is five times that of steel, which means that the heat dissipates very quickly. Therefore, welding currents and voltages for welding aluminum are higher than they are for steel so operators actually need heavier duty equipment for aluminum.

 

[Richard.]

It does

Those stealth units you sell jim could be the ticket here as I remember you saying they were good for the cash. What would you do one of those with a pedal for roughly mate.

 

[Jim Davey]

Er, had 3/4 of a bottle of wine now Rich and can't remember but I think 650 rings a bell. I'll check in the morning...hic!

 

[Richard.]

Not in anyway arguing with you rich but quote below on conductivity from Lincolns website says I am correct from a certain point of view

Many inexperienced aluminum welders use preheat as a crutch. Since equipment for welding aluminum needs to operate at higher capacities. Aluminum has a low melting point -- 1200° F compared to 2600° F to 2700° F for steel. Because of this low melting point, many operators think they only need light duty equipment to weld the aluminum. But, the thermal conductivity of aluminum is five times that of steel, which means that the heat dissipates very quickly. Therefore, welding currents and voltages for welding aluminum are higher than they are for steel so operators actually need heavier duty equipment for aluminum.

Fair point Nicky, yes makes sense.
The oxide layer does play a big part in the amount of current needed mind. You'll see as you start to weld the oxide layer is pushed aside as your hitting it with current then the pool comes through from the Alu under it. The two very different melting points. Does make a difference to the current needed at start off.

 

[paulmitchell1984]

what welders are those JIm?

 

[Paul.]

That's not correct Nicky the reason why you need so much current to get Alu flowing to start with is you need it to punch through that oxide layer which melts at 3 times higher than the aluminium underneath. This is why a pedal comes in handy. You need a good blast to punch through that oxide layer (1800 degC) then back off to gain control when the Alu starts flowing which melts at only 600degC.

I have to disagree with this Rich, the cleaning action is provided by the AC cycle, its called the scavenging effect or at least it was when I learned to weld 40 odd years ago. the cleaning is carried by electrode going positive, hence the ability to vary cleaning by altering the ac balance on machines that have that facility,

 

[Richard.]

I have to disagree with this Rich, the cleaning action is provided by the AC cycle, its called the scavenging effect or at least it was when I learned to weld 40 odd years ago. the cleaning is carried by electrode going positive, hence the ability to vary cleaning by altering the ac balance on machines that have that facility,

Yes the Ep cleaning cycle lifts the oxide layer Paul but you still need more current with it to punch through. You could alter the balance round to 50% but if you've not got the high current to start with you wont get through it.

 

[Burdekin]

Er, had 3/4 of a bottle of wine now Rich and can't remember but I think 650 rings a bell. I'll check in the morning...hic!

Must be good wine Jim. ;-) From memory I think you sold the one in your post about the machine for £850, but if they are £650 with a pedal that's an awesome deal.

 

[Richard.]

This is why it is possible to weld Alu in dc with a helium mix. It doesn't clean very well as you've not got the positive half wave doing as you say lifting the oxide layer but the hotter arc from the helium mix helps punch through the high melting point oxide layer

 

[Jim Davey]

what welders are those JIm?

These

 

[Jim Davey]

Must be good wine Jim. ;-) From memory I think you sold the one in your post about the machine for £850, but if they are £650 with a pedal that's an awesome deal.

I better stop drinking and posting before I bankrupt myself...

 

[paulmitchell1984]

650 sounds good hehe (unless its cheaper then its not) , let me know i could be interested

 

[Jim Davey]

650 is probably what the machine costs me :s

 

[paulmitchell1984]

same as this ?

http://www.thewelderswarehouse.com/Welding/Tig-Welder-SWP-Stealth-180PD.html

just looked one i listed is only 185

 

[Tom Orrow L]

same as this ?

http://www.thewelderswarehouse.com/Welding/Tig-Welder-SWP-Stealth-180PD.html

just looked one i listed is only 185

The stealth 200 AC DC is the one of up from that. Jim could sort you with one of those easy, I've sold plenty of them and had good reviews so you shouldn't have aby issue.. They're actually the most affordable UK supported ac Dc TIG on the market.

 

[Jim Davey]

Lovely little welder for the money, I can't fault it.

 

[paulmitchell1984]

let me know Jim