1. TIG Welding Introduction

2. Background What is TIG? Also referred to as GTAW
Tungsten Inert Gas
Also referred to as GTAW
Gas Shielded Tungsten Welding
In TIG welding, a tungsten electrode heats the metal you are welding and gas (most typically Argon) protects the weld from airborne contaminants

3. Background TIG welding uses a non-consumable tungsten
Filler metal, when required, is added by hand
Shielding gas protects the weld and tungsten

4. Advantages Welds more metals and metal alloys than any other process
High quality and precision
Pin point control
Aesthetic weld beads
No sparks or spatter
No flux or slag
No smoke or fumes

5. Disadvantages Lower filler metal deposition rates
Good hand-eye coordination a required skill
Brighter UV rays than other processes
Slower travel speeds than other processes
Equipment costs tend to be higher than other processes

6. Safety Electric shock can kill.
Always wear dry insulating gloves
Insulate yourself from work and ground
Do not touch live electrical parts
Keep all panels and covers securely in place
Fumes and gases can be hazardous to your health.
Keep your head out of the fumes
Ventilate area, or use breathing device

7. Safety Welding can cause fire or explosion.
Do not weld near flammable material
Watch for fire; keep extinguisher nearby
Do not locate unit over combustible surfaces
Do not weld on closed containers
Arc rays can burn eyes and skin; Noise can damage hearing.
Wear welding helmet with correct shade of filter
Wear correct eye, ear, and body protection

8. Safety Hot parts can cause injury.
Allow cooling period before touching welded metal
Wear protective gloves and clothing
Magnetic fields from high currents can affect pacemaker operation.
Flying metal can injure eyes.
Welding, chipping, wire brushing, and grinding cause sparks and flying metal; wear approved safety glasses with side shields

9. Safety Welding current can damage electronic parts in vehicles.
Disconnect both battery cables before welding on a vehicle
Place work clamp as close to the weld as possible

10. Techniques for Basic Weld Joints
Arc Starting with High Frequency
Torch position on left shows recommended method of starting the arc with high frequency when the torch is held manually
By resting gas cup on base metal there is little danger of touching the electrode to the work
After arc is initiated, torch can be raised to proper welding angle
*Figure copied from “TIG Handbook”

11. Techniques for Basic Weld Joints
Manual Torch Movement
ENBE 499
*Figure copied from “TIG Handbook”

12. TIG Shielding Gases
Argon
Helium
Argon/Helium Mixtures

13. TIG Shielding Gases Helium Argon Good arc starting
Good cleaning action
Good arc stability
Focused arc cone
Lower arc voltages
10-30 CFH flow rates
Helium
Faster travel speeds
Increased penetration
Difficult arc starting
Less cleaning action
Less low amp stability
Flared arc cone
Higher arc voltages
Higher flow rates (2x)
Higher cost than argon

14. TIG Shielding Gases Argon/Helium Mixtures
Improved travel speeds over pure argon
Improved penetration over pure argon
Cleaning properties closer to pure argon
Improved arc starting over pure helium
Improved arc stability over pure helium
Arc cone shape more focused than pure helium
Arc voltages between pure argon and pure helium
Higher flow rates than pure argon
Costs higher than pure argon