Lincoln Electric IM992 TIG Welding, Typical Current Ranges 1 for Tungsten ELECTRODES2, TAbLE b.3

b-6 OPERATION b-6

Once the arc is started, normal welding technique for the application is then used.

NOTE: With the VRD switch in the “ON” position there is no output in the DOWNHILL PIPE mode. For indicator light operation, see table B.1.

For other electrodes the above techniques should be							TIG WELDING
tried first and varied as needed to suit operator prefer-
ence. The goal for successful starting is good metal to							The TOUCH START TIG setting of the MODE switch is for
metal contact.
							DC TIG (Tungsten Inert Gas) welding. To initiate a weld,
For indicator light operation, see table B.1.							the OUTPUT CONTROL dial is first set to the desired cur-
							rent and the tungsten is touched to the work. During the
DOWNHILL PIPE Welding							time the tungsten is touching the work there is very little
							voltage or current and, in general, no tungsten contamina-
This slope controlled setting is intended for "out-of-posi-							tion. Then, the tungsten is gently lifted off the work in a
							rocking motion, which establishes the arc.
tion" and "down hill" pipe welding where the operator
							When in the TOUCH START TIG mode and when a
would like to control the current level by changing the arc
							Amptrol is connected to the 6-Pin connector the OUT-
length.
							PUT CONTROL dial is used to set the maximum cur-
The OUTPUT CONTROL dial adjusts the full output range							rent range of the current control of the Amptrol.
for pipe welding.							The ARC CONTROL is not active in the TIG mode. To
The ARC CONTROL dial sets the short circuit current							STOP a weld, simply pull the TIG torch away from the
							work. When the arc voltage reaches approximately 30
(arc-force) during stick welding to adjust for a soft or more
							Volts the arc will go out and the machine will reset the
forceful digging arc (crisp). Increasing the number from -
							current to the Touch Start level.
10(soft) to +10(crisp) increases the short circuit current
							To reinitiate the arc, retouch the tungsten to the work
which results in a more forceful digging arc.Typically a
							and lift. Alternatively, the weld can be stopped by
forceful digging arc is preferred for root and hot passes. A
							releasing the Amptrol or arc start switch.
softer arc is preferred for fill and cap passes where weld
puddle control and deposition (“stacking” of iron) are key							The VANTAGE® 300 can be used in a wide variety of
to fast travel speeds. This can also increase spatter.
							DC TIG welding applications. In general the ‘Touch
It is recommended that the ARC CONTROL be set to the
							Start’ feature allows contamination free starting without
minimum number without electrode sticking. Start with the							the use of a Hi-frequency unit. If desired, the K930-2
dial set at 0.							TIG Module can be used with the VANTAGE® 300.
					TAbLE b.3		The settings are for reference.
		TYPICAL CURRENT RANGES (1) FOR TUNGSTEN ELECTRODES(2)
	Tungsten Electrode		DCEN (-)	DCEP (+)	Approximate Argon Gas Flow					TIG TORCH
	Diameter in. (mm)				Flow Rate C.F.H. ( l /min.)					Nozzle Size (4), (5)
			1%, 2% Thoriated	1%, 2% Thoriated	Aluminum			Stainless Steel
			Tungsten	Tungsten
	.010	(.25)	2-15	(3)	3-8	(2-4)		3-8	(2-4)	#4, #5, #6
	0.020	(.50)	5-20	(3)	5-10	(3-5)		5-10	(3-5)
	0.040	(1.0)	15-80	(3)	5-10	(3-5)		5-10	(3-5)
	1/16	(1.6)	70-150	10-20	5-10	(3-5)		9-13	(4-6)	#5, #6
	3/32	(2.4)	150-250	15-30	13-17	(6-8)		11-15	(5-7)	#6, #7, #8
	1/8	(3.2)	250-400	25-40	15-23	(7-11)		11-15	(5-7)
	5/32	(4.0)	400-500	40-55	21-25	(10-12)		13-17	(6-8)	#8, #10
	3/16	(4.8)	500-750	55-80	23-27	(11-13)		18-22	(8-10)
	1/4	(6.4)	750-1000	80-125	28-32	(13-15)		23-27	(11-13)

(1)When used with argon gas. The current ranges shown must be reduced when using argon/helium or pure helium shielding gases.

(2)Tungsten electrodes are classified as follows by the American Welding Society (AWS):

Pure	EWP
1% Thoriated	EWTh-1
2% Thoriated	EWTh-2

Though not yet recognized by the AWS, Ceriated Tungsten is now widely accepted as a substitute for 2% Thoriated Tungsten in AC and DC applications.

(3)DCEP is not commonly used in these sizes.

(4)TIG torch nozzle "sizes" are in multiples of 1/16ths of an inch:

# 4 = 1/4 in.		(6 mm)
# 5	= 5/16 in.	(8 mm)
# 6	= 3/8 in.	(10 mm)
# 7	= 7/16 in.	(11 mm)
# 8	= _ in.	(12.5 mm)
#10 = 5/8 in.		(16 mm)

(5)TIG torch nozzles are typically made from alumina ceramic. Special applications may require lava nozzles, which are less prone to breakage, but cannot withstand high temperatures and high duty cycles.

VANTAGE® 300