[TheForge] Choosing a tig welder

[Ralph Sproul]

> I haven't put a meter on either of my machines. Given constant input
> voltage, the only variable is current, right? So do you find that a tig
> draws more current (and therefore more power [W]) at a given
> setting--or for a given job--than migs?

> Justin.


    Current driven machines tend to use amps.  The migs run at a voltage -
but the proportional feed of the wire into the short arc or spray transfer
makes for amperage use as well.
    The major point in this is running a starting current to heat up your
material for weld puddle start up.......ALONG with running a high
voltage/high frequency starting current over the welding current.  This
takes a lot of power - and is often why the old Miller Syncrowaves wanted a
#1 or #2 copper pigtails to feed the machine - not something like a #4 as
you wanted no current restrictions on the machine demanding current for both
welding and arc initiation.  This is why I'm offering the warning about "Old
Industrial Machines" requiring a lot of power and you may save money on the
purchase of one of those machines, but the electrical wiring to meet the
welding and arc starting needs of those old machines - can be more than the
welder's cost.  An example of this is I have an old Miller Tig machine -
that needs 125 input amps and large wire size to feed the welder/start up.
I had this wiring, but if your panel only offers 50 to 100 amps.......and
you have to change the panel and service to get a 200 amp service to run the
welder and other accessories and tools around your shop - you are not going
to like the cost of this as compared to the welder savings you thought you
had.

        Even those little Miller Tig welders are inverters.  Thermal
Dynamics also offered a small inverter Tig unit.  Both these welders have
had good reports from many people that I've talked to.

Ralph