need high freq box help

Date 06-03-2002 23:13

hey all,
i just got new miller 301g engine driven. want to get into alum tig. i have done lots of tig but not off this type of machine. i have a tig torch with gas valve and thumb remote. do i need a plain in/out high freq box or do i need the get millers 700 dollar box. i dont have a clue. the machine i use at work is an older lincoln stick tig machine thats prob. at least 30 yrs old. need some info on what i need. do i really need the high freq for dc tig? help!!
clueless

By Lawrence (*****)

Date 06-04-2002 14:09

DC electrode negetive (DC-) Tig welding of Aluminum requires helium as a shield gas but not HF.

The superimposed HF is used for AC (Alternating Current) Welding and for arc starting assistence.

Can you scratch start using DC- and helium to weld Aluminum? Maybe.... the work will have to be very clean, fabrication is alot more condusive to this method than repair welding.

Generally field welds of aluminum are accomplished with AC.

Tell us a little more about your project.

What type Alum? Cast? Extrusion? Sheet? Series?

Thickness? and any other parameter that would give more detail

Lawrence