WeldCraft WP-280-12-RM, Owner'S Manual

OM-254 691 Page 10

SECTION 5 

−

 SELECTING AND PREPARING A TUNGSTEN

FOR DC OR AC WELDING WITH INVERTER MACHINES

gtaw_Inverter_2011-06

Whenever possible and practical, use DC weld output instead of AC weld output.

5-1. Selecting Tungsten Electrode (

Wear Clean Gloves To Prevent Contamination Of Tungsten

)

Not all tungsten electrode manufacturers use the same colors to identify tungsten type. Contact the tungsten electrode manufacturer or reference
the product packaging to identify the tungsten you are using.

Amperage Range - Gas Type



 - Polarity

Electrode Diameter

(DCEN) 

−

 Argon

Direct Current Electrode Negative

(For  Use With Mild Or Stainless Steel)

AC 

−

 Argon

Balance Control @ 65%  Electrode Negative

(For Use With Aluminum)

2% Ceria, 1.5% Lanthanum, Or 2% Thorium Alloy Tungstens

.010 in. (1 mm)

Up to 25

Up to 20

.020 in. (1 mm)

15-40

15-35

.040 in. (1 mm)

25-85

20-80

1/16 in. (1.6 mm)

50-160

50-150

3/32 in. (2.4 mm)

130-250

135-235

1/8 in. (3.2 mm)

250-400

225-360

5/32 in. (4.0 mm)

400-500

300-450

3/16 in (4.8 mm)

500-750

400-500

1/4 in. (6.4 mm)

750-1000

600-800



Typical argon shielding gas flow rates are 11 to 35 CFH (cubic feet per hour).

Figures listed are a guide and are a composite of recommendations from American Welding Society (AWS) and electrode manufacturers.

5-2. Preparing Tungsten Electrode For DC Electrode Negative (DCEN) Welding Or AC

Welding With Inverter Machines

Grinding the tungsten electrode produces dust and flying sparks which can  cause injury and start fires.

Use local exhaust (forced ventilation) at the grinder or wear an approved respirator.  Read MSDS for safety

information. Consider using tungsten containing ceria,  lanthana, or yttria  instead of thoria. Grinding dust

from thoriated electrodes contains low-level radioactive material.  Properly dispose of grinder dust in an

environmentally safe way. Wear  proper face, hand,  and body protection. Keep flammables away.

Ideal Tungsten Preparation 

−

 Stable Arc

2-1/2 Times

Electrode Diameter

1

Grinding Wheel

Grind end of tungsten on fine grit, hard

abrasive wheel before welding. Do not use

wheel for other jobs or tungsten can become

contaminated causing lower weld quality.
2

Tungsten Electrode

A 2% ceriated tungsten is recommended.
3

Flat

Diameter of this flat determines amperage

capacity.
4

Straight Ground

Grind lengthwise, 

not radial

.

1

3

4

Causes Wandering Arc

2

Wrong Tungsten

Radial Grinding

Preparation