I hear people talk about TIG welding, but My uncle was a "heliarc welder". Whats the difference?
The
"TIG" in TIG welding stands for Tungsten Inert Gas. But Before it was
called TIG" it was given the name "Heliarc" because helium was the gas
that was used when the process was invented. But then someone
discovered that argon worked better and so it was called TIG because
inert gas could refer to either helium or argon. But wait, then someone
else discovered that small additions of hydrogen worked well for some
metals. The word "Inert" no longer held true so the eggheads decided a
new name was required. So nowadays, the technical term for what used to
be called TIG and Heliarc is Gas Tungsten Arc Welding or "GTAW". But
Guess what? people still call it TIG and even Heliarc. In fact more
people call it TIG welding than Gas Tungsten Arc Welding.
Exactly What is TIG?
TIG
welding is akin to gas welding as far as welding technique in that the
torch is held in one hand and the filler rod is manipulated with the
other hand. It is considered more difficult than other arc welding
processes because it requires the use of both hands. Often times a foot
pedal amperage control is also used which adds another layer of
difficulty.
A TIG torch can be either water cooled or air cooled
and is designed to provide shielding gas as well as welding current
through a tungsten electrode. A ceramic nozzle directs the shielding
gas to the weld puddle and internal copper parts like the collet and
collet body hold the electrode in place. The tungsten electrode is
sharpened for applications where the arc needs to be pinpointed and for
very low amperage. The heat the melts the metal and makes the weld
puddle comes from the arc that is created between the tungsten
electrode and the workpiece. The arc is shielded by argon, helium, or a
mixture of the two. Sometimes for certain alloys, hydrogen is added in
small percentages to improve the way the puddle flows. The arc is very
smooth and quiet and clean when DC current is used. When the TIG
welding machine is set on Alternating current, it is slightly more
noisy but still clean and smooth.
What Metals can be welded using the TIG process?
Almost
any metal can be welded with TIG. Carbon and low alloys steels like
1010 carbon steel and 4130 chromoly steel,Stainless steels like 304,
321, and 17-7ph, Nickel alloys like inconel 718 and Hastelloy X,
Aluminum alloys like 6061,5052, Magnesium alloys like az31b, Titanium
alloys like commercially pure, and 6al4v, Cobalt alloys like Stellite
6b and l605, copper alloys like Nibral bronze and pure copper, All can
be welding using the TIG welding process.
How can I learn how to TIG weld?
There are plenty of websites out there that offer basic TIG process fundamentals. www.millerwelds.com is a good resource for example. But you need more than a website to be a good TIG welder. Training and practice are critical.
I
would recommend a TIG Training DVD like the one available from Hobart
institute of Welding or from Miller welding along with some focussed
practice on different material types.
When it comes to learning how to TIG, the 3 P's come into play:
- Practice
- Practice
- Practice
And when it comes to the metal being welding the 3 C's are important:
- Clean
- Clean
- Clean
