Lincoln Electric IM887 manual Making a Weld

MAGNUM 250 LX - OPERATING INSTRUCTIONS

Making A Weld

1.Check that the spool gun power, control, and gas connections are correct for the power source being used. Check that the gas supply is turned on. Check wire spool for an adequate supply of wire.

2.See "Procedure Settings", below for wire feed speed and voltage settings. Set these controls depending on the welding wire and base metal thickness being used.

3.Connect work clamp to metal being welded. Work clamp must make good electrical contact to the workpiece. The workpiece must also be grounded as stated in "Arc Welding Safety Precautions".

4.Connect power to welder and turn "ON".

5.Prepare to purge gas line by first releasing wire drive. Push wire drive release lever to the UP position, to avoid feeding wire.

WARNING: Gun body and contact tip become electri- cally energized when gun trigger is pressed and remain so for several seconds after trigger is released.

6.Press and hold gun trigger for about 5 seconds to purge gas line. If adjustable regulator or metering valve is installed, adjust gas flow per, "Setting Gas Flow Rate".

7.Re-engage wire drive by pushing release lever to down position to feed wire.

8.Momentarily squeeze trigger and verify that wire feeds properly. Trim wire to approximately 1/4" (6 mm) from end of contact tip.

WARNING: When using an open arc process, it is neces- sary to use correct eye, ear, head, and body protection.

9.Position gun over joint at 10° pushing angle. End of wire may be lightly touching the work.

10.Lower welding helmet, close gun trigger, and begin welding. Hold the gun so that the contact tip to work distance is about 1/2 inch (13 mm).

11.To stop welding, release the gun trigger and then pull the gun away from the work after the arc goes out.

12.When no more welding is to be done, close valve on gas cylinder, momentarily operate trigger to release gas pressure in line and turn off power source.

13.Note that clogged tips can often be salvaged by peeling away melted wire.

Procedure Settings

The following procedure settings for 4043 aluminum wire and argon gas can be used as starting points for developing specific welding procedures:

Wire		Metal		Wire		Amps
Size		Thickness		Speed		DC
in. (mm)	ga.	in. (mm)	Arc Volts	ipm (mpm)		(+}
.030 (0.8)	22	.030 (0.8)	13-14(1)	200	(5.1)	40
	20	.036 (1.0)	13-14(1)	240	(6.1)	40
	18	.048 (1.2)	14-15(1)	290	(7.4)	50
	16	.060 (1.6)	15-16(1)	340	(8.6)	60
	14	.075 (2.0)	16-17(1)	370	(9.4)	70
	12	.105 (2.5)	16-18(1)	430 (10.9)		90
	10	.135 (3.5)	24-26	460 (11.7)		110
	3/16	(5.0)	24-26	500 (12.7)		150
	1/4	(6.0)	28-29	560 (14.2)		180
	3/8	(10.0)	28-30	600 (15.2)		200
.035 (0.9)	22	.030 (0.8)	13-14(1)	150	(3.8)	40
			(1)
	20	.036 (1.0)	13-14(1)	175	(4.4)	40
	18	.048 (1.2)	13-14(1)	215	(5.5)	50
	16	.060 (1.6)	14-16	250	(6.4)	60
	14	.075 (2.0)	14-16(1)	270	(6.9)	70
	12	.105 (2.5)	16-18(1)	320	(8.1)	90
	10	.135 (3.5)	24-26	410 (10.4)		110
	3/16	(5.0)	24-26	450 (11.4)		150
	1/4	(6.0)	26-28	530 (13.5)		180
	3/8	(10.0)	26-29	560 (14.2)		200
	1/2	(12.0)	26-30	600 (15.2)		220
3/64(1.2)	10	.135 (3.5)	20-21(1)	180	(4.6)	110
	3/16	(5.0)	20-21(1)	220	(5.6)	150
	1/4	(6.0)	27-28	250	(6.4)	180
	3/8	(10.0)	25-30	260	(6.6)	200
	1/2	(12.0)	25-31	270	(6.9)	220
	3/4	(20.0)	25-31	290	(7.4)	250

(1)Short arc transfer.

Setting Gas Flow Rate

Gas handling systems having adjustable flow valves should be set for the following argon flow rates, depending on base metal thickness and welding position.

ARGON SHIELDING GAS FLOW RATES

Material Thickness		Flow Rates
In Inches and (mm)	Welding Position	In cf/hr (l/mln)
1/16 (1.6 mm)	Flat	30
		(11.8)
3/32 to 3/16	Flat, Vertical,	35
(2.4 to 4.8 mm)	Horizontal, Overhead	(14)
1/4 to 3/8	Flat, Vertical,	35 (14)
(6.3 to 9.5 mm)	Flat Vertical,	35 (16.5)
	Horizontal, Overhead	40 (18.9)
3/4 (19 mm)	Flat, Vertical	35 (16.5)
	Horizontal, Overhead	40 (18.9)

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