[ RadSafe ] RE: TIG Welding

[Shawn Hughes (Road2)]

Hey!

Something else I can chime in on....

One of the projects I've consulted on is helping a friend start up a large
welder repair shop. I am certified through Miller as a welder repairman.

Very simply, most electric welders are large, dumb AC to DC transformers.
The problem is what welders call 'striking an arc'. With a traditional
welder, it is hard to get the welding process started. TIG/MIG and other
technologies get past this by an introduction of a small high-frequency
radio signal into the DC welding leads. This makes it easier for the
electricity to jump the air gap (to be technical, with TIG, an inert gas
flows from the workpiece surrounding the welding rod, providing a near inert
field to weld in) to begin welding, and once the arc starts, in many cases,
the RF portion is automatically turned off. The exciter for this part is RF
shielded inside the unit, but as far as occupational exposure to the
operator, no. You CAN get a sunburn, but that is a byproduct of UV radiation
emitted by the various welding rods, and zero to do with the starter.

I think the instructor is yanking this guys' leg.




> A third  year journeyman welder has titanium implants in his face due to
> facial fractures from his youth.
>
> His technical college welding instructor told him that TIG welding is
like
> putting his face in a microwave.  Now he is worried and wants the
titanium
> implants removed.

It appears that the bulk of TIG welding is done 
with mains-operated AC arcs. There appears to be 
benefits to using AC over DC in the welding process.
 

-Shawn+++++++++++++++++++++++++++++++++++++++++++++++++++++
Shawn R. Hughes
Special Projects Consultant
near Oak Ridge, Tennessee
srh at esper.com primary email
www.shawnrhughes.com fledgling webpage
 
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