Forney 140 MIG WELDER User manual

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140 MIG WELDER
OWNER’S MANUAL
IDEAL FOR:
Do-It-Yourself, Agriculture, Maintenance & Repair,
Contractor, Automotive, Metal Fabrication Hobbyist and
More...
INCLUDES:
12’ Welding Torch; Ground Clamp; 8’ Power Cable; Gas
Hose and Regulator
CAT. #00309 WELDER FEATURES:
• Welding range up to 140 Amps / 120V Input
• Can be used for Mild Steel, Stainless Steel,
Aluminum and Cast Iron
• Large cabinet with easy access to 4” and 8” spools
• Metallic heavy-duty wire drive system
• Torch/Cable wrap
• 12’ Premium MIG torch with Euro disconnect and
Tweco®style consumables
LR114649

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STOP PLEASE!
DO NOT RETURN
TO THE STORE
If you have questions or problems with your new Welder, please
call customer service at 1-800-521-6038 Monday through
Friday from 7am-5pm Mountain Time or at
www.forneyind.com/customer_service.
Please take time to register your product at
www.forneyind.com/customer_service/register_your_product/.
This qualifies you for our industry leading 5/3/1 warranty.
Thank you, enjoy your new Welder.

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Forney Promise
We are committed to your success regardless of location, size or
needs. We understand it is your goal to get the job done right,
and we are ready to help you do just that.
President's Message
We market the highest quality tools, equipment and accessories
for the do-it-yourselfer and professional. Our passion and
dedication in bringing new products to the industrial and retail
market, combined with our personal service, is unmatched in our
industry. Our ability to listen to our customers’ needs enables us to
create solutions to their problems.
Our dedication to the highest quality customer service within our
corporate headquarters and the service provided in the field is
unequaled. We are committed to creating the best solutions to our
customer’s needs. Above all, our employees will provide the same
respect and caring attitude within the organization as they are
expected to share with every Forney customer. Our goal will be to
exceed our customers’ expectations through empowered people,
guided by shared values and commitments.
We work hard so our customers trust us because of our integrity,
teamwork and innovation of Forney products, and Forney’s
80 years of unmatched product quality and an unwavering
commitment to our customers.
When our customers succeed we succeed.
STEVEN G. ANDERSON, President & CEO
Copyright© 2014 Forney Industries,
Inc. All rights reserved. Unauthorized
reproduction and/or distribution is
subject to US copyright laws.
U.S. Warehouses:
- Fort Collins CO
- Tipp City OH
FIVE WAYS TO ORDER
Web: www.forneyind.com
Phone: [phone]
Fax: [phone]
Mail: Forney Industries
1830 Laporte Avenue
Fort Collins, CO 80521
Email: [e-mail]

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Forney 5/3/1 Limited Warranty
Effective August 1st, 2009
1) Limited Warranty: Subject to the terms and conditions below, Forney Industries, Inc., Fort Collins,
Colorado, warrants to its original retail purchaser that the new Forney equipment sold after the effective date
of this limited warranty is free of defects in material and workmanship at the time it is shipped by Forney. This
is in lieu of all other warranties, express or implied.
2) Notification: Please call 1-800-521-6038 with your warranty questions. You can also visit www.
forneyind.com for additional information about your new welder.
3) Length of Warranty: Within the warranty periods listed below, Forney will repair or replace any
warranted parts or components that fail due to defects in material or workmanship. Warranty is effective
from the date of original retail purchase. Warranty duration is as follows:
A) 5 years: Original main power rectifiers only to include SCRs, diodes and discrete rectifier modules,
transformers, stabilizers and reactors.
B) 3 years: Drive Systems, PC Boards, Motors, Switches and Controls.
C) 1 year: MIG guns, relays, contractors and regulators, plasma cutting torches, and accessories.
D) 90 days: Replacement parts. Does not include labor.
4) Non-Applicable Parts: Forney’s limited warranty shall not apply to consumables such as contact tips,
cutting nozzles, felt wire cleaner, drive rollers, gas diffusers, plasma torch tips and electrodes, weld cables,
tips and parts that fail due to normal wear. In addition, this warranty does not extend to any damage caused
by the untimely replacement or maintenance of any of the previously listed consumable parts.
5) Warrantor:
Forney Industries
1830 Laporte Avenue
Fort Collins, CO 80521
1-800-521-6038
www.forneyind.com.
6) Purchaser / Warranty: The original purchaser of the Forney Industries product. The warranty is
not transferable. Forney Industries products are intended for purchase and use by persons trained and
experienced in the use and maintenance of welding equipment.
7) What is not covered under the warranty:
A) Implied warranties, including those of merchantability and fitness for a particular purpose are limited in
duration to this express warranty. After this period, all risks of loss, from whatever reason, shall be on the
purchaser.
B) Any incidental, indirect, or consequential loss, damage, or expense that may result from any defect,
failure or malfunction of the Forney product.
C) Any failure that results from accident, purchaser’s abuse, neglect or failure to operate products in
accordance with instructions provided in the owner’s manual(s) supplied with the product.
D) Pre-delivery service, i.e. assembly and adjustment.
8) Claim: In the event of a warranty claim under this warranty, the exclusive remedies shall be, at Forney
Industries sole option:
A) Repair; or
B) Replacement; or
C) Where authorized in writing by Forney Industries, the cost of repair or replacement at an authorized
Forney Industries Service Center; or
D) Payment of or credit for the purchase price less reasonable depreciation based on actual use upon the
return of the goods at the customer’s risk and expense.
9) Purchaser will:
A) Contact Forney’s Customer Service at 1-800-521-6038 within 30 days of the defect or failure.
B) Provide dated proof of purchase (typically a purchase receipt).
C) Provide the serial number. Registering your welder at registration.forneyind.com:442 will speed up this
process.
D) Deliver or ship welder to a Forney authorized Service Center. Freight &/or packaging costs, if any, must
be borne by the purchaser.

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WARRANTY.................................................................................................................................. 4
TABLE OF CONTENTS.................................................................................................................... 5
SAFETY INFORMATION ................................................................................................................. 6
ASSEMBLY AND MAJOR COMPONENTS...................................................................................... 11
SET UP CHART ............................................................................................................................ 14
FRONT PANEL OPERATION..........................................................................................................15
GENERAL OPERATING INSTRUCTIONS......................................................................................... 16
TROUBLESHOOTING................................................................................................................... 18
SPARE PARTS AND DIAGRAMS.................................................................................................... 20
TABLE OF CONTENTS

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CAUTION!
BEFORE INSTALLING, OPERATING OR CARRYING OUT MAINTENANCE ON THE 210 WELDER,
READ THE CONTENTS OF THIS MANUAL CAREFULLY, PAYING PARTICULAR ATTENTION TO THE
SAFETY RULES AND HAZARDS.
In the event of these instructions not being clear, please contact your
Forney Authorized Dealer or Forney Customer Service 1-800-521-6038
Safety Information READ BEFORE USING
Principal Safety Standards
• Safety in Welding and Cutting, ANSI Standard Z49.1, from American Welding Society, 8669 Doral
Boulevard, Suite 130, Doral, FL 33166 Safety and Health Standards, OSHA 29 CFR 1910, from
Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402.
• Recommended Safe Practices for the Preparation for Welding and Cutting of Containers That Have
Held Hazardous Substances, American Welding Society Standard AWS F4.1, from American
Welding Society, 8669 Doral Boulevard, Suite 130, Doral, FL 33166
• National Electrical Code, NFPA Standard 70, from National Fire Protection Association,
Batterymarch Park, Quincy, MA 02269.
• Safe Handling of Compressed Gases in Cylinders, CGA Pamphlet P-1, from Compressed Gas
Association, 1235 Jefferson Davis Highway, Suite 501, Arlington, VA 22202.
• Code for Safety in Welding and Cutting, CSA Standard W117.2, from Canadian Standards
Association, Standards Sales, 178 Rexdale Boulevard, Rexdale, Ontario, Canada M9W 1R3.
• Safe Practices For Occupation And Educational Eye And Face Protection, ANSI Standard Z87.1,
from American National Standards Institute, 1430 Broadway, New York, NY 10018.
• Cutting And Welding Processes, NFPA Standard 51B, from National Fire Protection Association,
Batterymarch Park, Quincy, MA 02269
EMF Information
Considerations about Welding or Cutting and the Effects of Low Frequency Electric and Magnetic Fields
Welding or cutting current, as it flows through the welding or cutting cables, will cause electromagnetic
fields. There has been and still is some concern about such fields. However, after examination the
committee of the National Research Council concluded that: “The body of evidence, in the committee’s
judgment, has not demonstrated that exposure to power-frequency electric and a magnetic field is a
human health hazard.” However, studies are still going forth and evidence continues to be examined.
Until the final conclusions of the research are reached, you may wish to minimize your exposure to
electromagnetic fields when welding or cutting.
To reduce magnetic fields in the workplace, use the following procedures:
1. Keep cables close together by twisting or taping them.
2. Arrange cables to one side and away from the operator.
3. Do not coil or drape cables around your body.
4. Keep welding or cutting power source and cables as far away from operator as practical.
5. Connect work clamp to work piece as close to the cut or weld as possible.
About Pacemakers & Hearing Aids:
Pacemaker & Hearing Aid wearers consult your doctor first. If cleared by your doctor, then following
the above procedures is recommended.

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Personal Protection
Welding processes of any kind can be dangerous not only to the operator but to any person situated
near the equipment, if safety and operating rules are not strictly observed.
Arc rays can injure your eyes and burn your skin. The welding arc produces very
bright ultraviolet and infrared light. These arc rays will damage your eyes and
burn your skin if you are not properly protected.
• Wear closed, non-flammable protective clothing without pockets or turned up trousers, gloves
and shoes with insulating sole and steel toe. Avoid oily greasy clothing.
• Wear a non-flammable welding helmet with appropriate filter lenses, designed so as to shield
the front and sides of the neck and face. Keep protective lens clean and replace them when
broken, cracked or spattered.
• Weld in a closed, but well ventilated area that does not open into other working areas.
• Never look at the arc without correct lens.
Gases and fumes produced during the welding process can be dangerous and hazardous to
your health.
• Adequate local exhaust ventilation must be used in the area. It should be provided through a
mobile hood or through a built-in system on the workbench that provides exhaust ventilation
from the sides, the front and below, but not from above the bench so as to avoid raising
dust and fumes. Local exhaust ventilation must be provided together with adequate general
ventilation and air circulation, particularly when work is done in a confined space.
• Welding process must be performed on metal surfaces thoroughly cleaned from rust or paint,
or zinc coatings to avoid production of harmful fumes. Parts degreased with a solvent must be,
thoroughly dried before welding.
• Be very careful when welding any metals which may contain one or more of the following:
Antimony Beryllium Cobalt Manganese Selenium Arsenic Cadmium
Copper Mercury Silver Barium Chromium Lead Nickel
Vanadium Zinc
• Remove all chlorinated solvents from the welding area before welding. Certain chlorinated
solvents decompose when exposed to ultraviolet radiation to form phosgene gas (nerve gas).
Fire and explosion can be caused by hot slag, sparks or the welding arc.
• Keep an approved fire extinguisher of the proper size and type in the working area. Inspect it
regularly to ensure that it is in proper working order.
• Remove all combustible materials from the working area. If you can not remove them, protect
them with fire-proof covers.
• Ventilate welding work areas adequately. Maintain sufficient air flow to prevent accumulation
of explosive or toxic concentrations of gases.
• Do not weld on containers that may have held combustibles.
• Continually monitor check welding area to make sure it is free of lingering sparks, slag or
glowing metal and flames.
• The work area must have a fireproof floor.
Fire Prevention

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WARNING: ELECTRIC SHOCK CAN KILL!
• A person qualified in First Aid techniques should always be present in the working area; If a
person is found unconscious and electric shock is suspected, do not touch the person if she or
he is in contact with cable or electric wires. Disconnect power from the machine, then use First
Aid. Use dry wood or other insulating materials to move cables, if necessary, away from the
person.
• Wear dry gloves and clothing. Insulate yourself from the work piece or other parts of the
welding circuit.
• Make sure the main line is properly grounded.
• Do not coil the torch or the ground cables around your body.
• Never touch or come in physical contact with any part of the input current circuit and welding
current circuit.
Electric Warning:
• Repair or replace all worn or damaged parts.
• Extra care must be taken when working in moist or damp areas.
• Install and maintain equipment according to local regulations.
• Disconnect power supply before performing any service or repair.
• Should you feel the slightest electrical shock, stop any welding immediately and do not use the
welder until the fault has been found and corrected.
Noise can cause permanent hearing loss. Welding processes can cause noise levels that exceed
safe limits. You must protect your ears from loud noise to prevent permanent loss of hearing.
• To protect your hearing from loud noise, wear protective ear plugs and/or ear muffs.
• Noise levels should be measured to be sure the decibels (sound) do not exceed safe levels.
Before installing your welder, carry out an inspection of the surrounding area, observing the
following guidelines:
• Make sure that there are no other power supply cables, control lines, telephone leads or other
equipment near the unit.
• Make sure that there are no radio receivers, electrical appliances, computers or other control
systems near the unit.
• People with pacemakers or hearing-aids should keep far from the welder.
! In particular cases special protection measures may be required.
Interference can be reduced by following these suggestions:
• If there is interference in the power source line, an E.M.F. filter can be mounted between the
outlet and the welder.
• The output cables of the welder should not be too long, kept together or connected to ground;
• After any maintenance all the panels of the welder must be securely fastened in place.
Electric Shock
Noise
Electromagnetic Compatibility

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Shielding Gas Cylinders contain gas under high pressure. If damaged, a cylinder can
explode. Treat them carefully.
• Arc welders use only inert or non-flammable gases for welding arc protection. It is important
to choose the appropriate gas for the type of welding being performed.
• Do not use gas from unidentified cylinders or damaged cylinders.
• Do not connnect the cylinder directly to the welder. Use a pressure regulator.
• Make sure the pressure regulator and the gauges function properly.
• Do not lubricate the regulator with oil or grease.
• Each regulator is designed for use with a specific gas. Make sure the regulator is designed for
the protective gas being used.
• Make sure that the cylinder is safely secured tightly to the welder with the chain provided.
• Never expose cylinders to sparks, slag, flame or excessive heat.
• Make sure that the gas hose is in good condition.
• Keep the gas hose away from the working area.
Be sure to locate the welder according to the following guidelines:
• In areas free from moisture and dust;
• In areas with ambient temperature between 30° to 90°F;
• In areas free from oil, steam and corrosive gases;
• In areas not subjected to abnormal vibration or shock;
• In areas not exposed to direct sunlight or rain;
• Place at a distance of 12” or more from walls or similar obstructions that could restrict natural
air flow for cooling.
Since the inhalation of welding fumes can be harmful, ensure that the welding area is effectively
ventilated.
Before you make any electrical connection, make sure that supply voltage and frequency
available at site are those stated in the ratings label of your welder.
The main supply voltage should be within ±10% of the rated main supply voltage. Too
low a voltage may cause poor welding performance. Too high a supply voltage will cause
components to overheat and possibly fail. The welder outlet must be:
• Correctly installed, if necessary, by a qualified electrician;
• Correctly grounded (electrically) in accordance with local regulations;
• Connected to the correct size electric circuit.
Protective Welding Gases
Installation Recommendations
Location
Ventilation
Main Supply Voltage Requirements

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Notes:
• Periodically inspect supply cable for any cracks or exposed wires. If it is not in good condition,
have it repaired by a Service Center.
• Do not pull violently the input power cable to disconnect it from supply outlet.
• Do not lay material or tools on the power supply cable. The cable may be damaged and result
in electrical shock.
• Keep the supply cable away from heat sources, oils, solvents or sharp edges.
• If you use an extension cord, keep it as straight as possible. For lengths up to 50 ft. use 12
AWG. For lengths up to 100 ft. use 10 AWG.
For your safety, before connecting the power source to the line, closely follow these instructions:
• An adequate two-pole switch must be inserted before the main outlet. This switch must be
equipped with time-delay fuses.
• The connection with ground must be made with a two-pole plug compatible with the above
mentioned socket.
• When working in a confined space, the welder must be kept outside the welding area and the
ground cable should be fixed to the workpiece. Never work in a damp or wet confined space.
• Do not use damaged input or welding cables.
• The welding torch should never be pointed at the operator’s or at other persons’ bodies.
• The welder must never be operated without its panels attached. This could cause serious injury
to the operator and could damage the equipment.
California Proposition 65 Warnings
Welding or cutting equipment and processes produce fumes or gases which contain chemicals
known to the State of California to cause birth defects and, in some cases, cancer. (California
Health & Safety Code Section 25249.5 et seq.)
Safety Instructions

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• Unpack the welder.
• Assemble the plastic top handle using the screws provided.
• Attach the welding torch cable to the threaded connection on the front of the welder.
• Attach the gas hose and the electrical connector.
Standard Gun or Torch Lead
The bottle (not supplied) should be located at the rear of the welder, fix the cylinder securely to
the work bench or to the wall to insure that it does not fall. For safety, and economy, ensure that
the regulator is fully closed, (turned counterclockwise) when not welding and when fitting or
removing the gas cylinder.
• Turn the regulator adjustment knob counterclockwise to ensure the valve is fully closed.
• Screw the gas regulator fully down on the gas bottle valve, and fully tighten.
• Connect the gas hose to the regulator securing with clip/nut provided.
• Open the cylinder valve, then set the gas flow to approx. 20-30 CFH on the regulator.
• Operate the torch trigger to ensure that the gas is flowing through the torch.
WARNING: Cylinders are highly pressurized. Handle with care. Serious accidents
can result from improper handling or misuse of compressed gas cylinders. Do not
drop the cylinder, knock it over, expose it to excessive heat, flames or sparks. Do not
strike it against other cylinders.
Assembly
Torch Lead Gun Assembly
Gas Cylinder and Regulator Connection

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• Connect the standard MIG torch to the threaded connector on the front of the welder, tighten
firmly by hand.
Ensure the gas and electrical supplies are disconnected. Before proceeding, remove the nozzle
and the contact tip from the torch.
• Open the side panel.
• Loosen the nut of the spool holder (brake drum)
and remove the spring and the external ring. (Fig.4)
• Remove the plastic protection from the spool (4) and
place the wire spool on on the spool holder.
• Mount the external ring, the spring and the
plastic lock nut again. These parts form the braking
system of the wire spool speed. NOTE: Do not
tighten the nut too much, excessive pressure strains
the wire feeding motor, while too little pressure does
not allow the immediate stop of the wire spool at the
end of the welding.
• Loosen and lower the plastic knob (A) (Fig.5). Open
the pressure arm (B) of the feeder
• Disconnect the wire from the edge of the wire spool
being careful to keep tension on the end of the wire.
Cut off a short section of the end of the wire to insure
a straight end. Insert the straight end into the wire inlet
guide (C) past the wire feed roll and into the wire liner.
Lower pressure arm (B) and lift pressure adjustment
knob (A) into place. Connect the input power cord
and turn on the welder. Press the torch trigger and observe the wire feeding into the torch liner.
Adjust the pressure on the wire with knob (A) to insure smooth feeding without slippage. Do not
over tighten the pressure adjustment as it may damage the motor. Close the welder side panel.
Remove the nozzle and contact tip from the welding torch. Straighten the torch cable to remove
any coils or kinks. Squeeze and hold the torch trigger until the wire appears at the end of the
torch neck. Turn off the welder and install the contact tip and nozzle.
WARNING: Keep the torch straight. When feeding a new wire through the liner, make sure
the wire is cut cleanly (no burrs or angles) and that at least 2 cm from the end is straight (no
curves). Failure to follow these instructions could cause damage to the liner.
MIG, “GMAW” - Fluxcore wire, “FCAW” Welding
Torch Connection
Wire Loading

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WARNING: When changing the wire diameter being used, or replacing the wire feed roll,
be sure that the correct groove for the wire diameter selected is inside, closest to the machine.
The wire is driven by the inside groove. Feed rolls are marked on the side identifying the
groove nearest that side.
When loading wire and watching for it to come through the torch neck, to avoid injury, do
not hold the torch close to your face, instead, direct the wire toward the floor. To avoid injury,
do not place fingers near the wire feed rolls when the wire feeder is operating.
Ensure the gas and electrical supplies are disconnected.
• Disconnect the torch from the machine.
• Place it on a flat surface and carefully remove the brass nut (1).
• Pull the liner out of the hose.
• Install the new liner and mount the brass nut (1) again. In case
you are replacing a Teflon wire liner, follow these instructions:
• Install the new liner followed by the collet (3).
• Insert the O ring (4) on the wire liner collet (4)and replace the
brass nut (1).
• Cut the wire liner close to the brass nut
WARNING: The length of the new wire liner must be
the same as the liner you have just pulled out of the hose.
• Connect the torch to the machine and install the wire into the feeding system.
WARNING: Cylinders are highly pressurized. Handle with care. Serious accidents can result
from improper handling or misuse of compresses gas cylinders. Do not drop the cylinder,
knock it over, expose it to excessive heat, flames or sparks. Do not strike it against other
cylinders.
The gas cylinder (not supplied) should be located at the rear of the welder, in a well ventilated
area and securely fixed to the work bench or to the wall to insure that it will not fall.
For safety, and economy, ensure that the regulator is fully closed, (turned counter-clockwise)
when not welding and when installing or removing the gas cylinder.
• Turn the regulator adjustment knob counter-clock wise to ensure the valve is fully closed.
• Install the gas regulator on the gas cylinder, tighten the connecting nut firmly to insure against
gas leakage.
• Connect the gas hose to the gas regulator.
• Open the cylinder valve, then set the gas flow to 20 - 35 CFH (cubic ft. per hour).
• Connect the ground cable to the positive terminal of the
Polarity Change Board inside the spool compartment.
• Connect the working cable to the negative terminal of
Polarity Change Board inside the spool compartment.
• Connect the ground cable to the negative terminal on the
Polarity Change Board inside the spool compartment
• Connect the working cable to the positive terminal of the
Polarity Change Board inside the spool compartment.
Replacing the Wire Liner
Gas Cylinder and Regulator Connection
Fluxcore Wire Welding, “FCAW”
MIG Welding, “GMAW”

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Regulation Knob
Voltage
Setting
Wire Feed
Setting
Voltage
Setting
Wire Feed
Setting
Voltage
Setting
Wire Feed
Setting
Voltage
Setting
Wire Feed
Setting
Voltage
Setting
Wire Feed
Setting
Voltage
Setting
Wire Feed
Setting
Voltage
Setting
Wire Feed
Setting
Mild Steel
Solid Wire
75% A + 25%
CO2 (ER70S-6)
.023” (0.6 mm) 1 3 1 3 2 7.5 2 7.5 3 8.5 4 9 - -
.030” (0.8 mm) 1 2 1 2 1 3.5 2 5.5 3 7 4 8 4 8 .035” (0.9 mm) - - - - 2 3 2 4 3 6 4 8 4 8
Flux Core Wire
(No Gas)
(E71T-GS)
.030” (0.8 mm) 1 2 1 2 1 3 2 5 4 8 4 9 4 9
.035” (0.9 mm) - - - - 1 2 2 4 4 8 4 8.5 4 8.5
Stainless Steel
Solid Wire
98% Ar
2% CO2
.023” (0.6 mm) 1 3 1 3 1 3.5 2 6 3 8.5 4 9 - - .030” (0.8 mm) - - 1 2 1 3.5 2 4 3 7 4 8 4 8
.035” (0.9 mm) - - - - 1 3 1 3.5 3 7 4 7.5 4 7.5
MATERIAL
(Wire) GAS WIRE ø
MATERIAL THICKNESS
24 Gauge
.0236” (.6 mm)
22 Gauge
.0315” (.8 mm)
20 Gauge
.0354” (.9 mm)
18 Gauge
.0236” (1.2 mm)
1/8” (3 mm) 3/16” (4.5 mm) 1/4” (6.4 mm)
140 MIG SET-UP CHART
Arc Voltage Control Wire Speed Control
This control sets the arc welding voltage. It is proportional to the amount of heat in the arc. Position 6 is the highest arc voltage or heat setting.
wire Feed
This sets the wire feed speed (WFS) of the electrode wire through the MIG gun. Position 0 is 80 IPM Position 10 is 700 IPM
Forney Industries, Inc.
www.forneyind.com
1
2
3
4
Pressure Adjust Device
POLARITY
CHANGE
+/-
Pressure Arm
Gun Cable End
Wire Spool Inlet Wire Guide Feedroll
MIG, “GMAW” Welding Setting Chart

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Metal GAS NOTE
Mild Steel CO2
Argon + CO2
Argon + CO2 + Oxygen
Argon controls spatter
Oxygen improves arc stability
Aluminum Argon
Argon + Helium
Arc stability, good fusion and minimum splatter.
Higher heat input suitable for heavy sections.
Minimum porosity.
Stainless Steel Argon + CO2 + Oxygen
Argon + Oxygen
Arc stability.
Minimum splatter.
Copper, Nickel & Alloys Argon
Argon + Helium
Suitable for light gauges because of low
flowability of the weld pool.
Higher heat input suitable for heavy sections.
Contact the technical service of your gas supplier to know the percentages of the different gasses
which are the most suitable to your application.
Units may be used with the standard torch.
1. Main ON/OFF switch and welding voltage adjustment:
2. Wire feed adjustment knob
To increase the wire speed, turn the potentiometer
clockwise; to decrease the wire speed, turn it counter-
clockwise. The same procedure decreases the
values on the welding parameters. Turn knob slowly.
3. Ground Clamp
4. MIG Torch/Gun
CAT# 309
120V MIG WIRE FEED WELDER
WELDING RANGE UP TO 140 AMPS
1
3
2
4
Shielding Gas Guide
Front Panel Operation
Welder Controls

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• Attach the ground clamp to the bare metal to be welded, making sure of good contact;
• Make sure that the wire-roller groove in the roller corresponds to the diameter of the wire
being used.
• Plug the machine into a suitable outlet.
• Completely open the gas cylinder valve. Adjust the gas pressure regulator to the correct flow rate.
Some experience is required to adjust and use a MIG welder. In MIG welding two parameters
are fundamental: the welding voltage and the wire speed. The resulting welding current is a
result of these two settings.
• Set the voltage and wire feed controls to positions suitable for the thickness of the material to
be welded. Welding current varies in relationship to wire feed speed. For low welding current
output, the wire feed speed potentiometer should be set at the low end of the wire feed speed
scale. Turning the wire feed speed control potentiometer clockwise. Will result in increased
wire feed speed and welding current. Welding voltage is adjusted to match the wire feed
speed (welding current). Progressively select higher voltage positions while increasing wire
speed.
Increasing welding voltage leads to a longer arc (without substantially affecting the current).
Conversely, a decreased welding voltage results in a shorter arc (the current again is not
substantially changed). A change in wire diameter results in changed parameters. A smaller
diameter wire requires an increase in wire feed speed to reach the same current. If certain limits
are exceeded, a satisfactory weld cannot be obtained. Refer to welding set up chart on page
(14) These are:
A) Feeding wire too fast (with regard to the welding voltage) results in pulsing within the torch.
This is because the wire electrode dips into the puddle and cannot be melted off fast enough.
B) Setting welding voltage to high (with regard to the wire feed speed), will result in excessive
and unstable arc. Increase the voltage even higher and the contact tip will burn.
C) Excessive wire speed can be corrected through the arc voltage increase. The limit of this
adjustment depends on the thickness of the material to welded (a certain limit exceeded will
result in burnthrough).
Place the torch on the joint you want to weld: the angle between the torch and the nozzle should
be around 45°. The distance between the torch and the work piece should be approximately
1/2”. Lower the face shield and press the torch trigger to start the arc. When the arc has struck,
move the nozzle slowly from left to right along the joint. Adjust the wire feed speed until the arc
makes a “crisp” sound (experience will help you to recognize the right sound).
The machine should be set up as for mild steel except for the following changes:
• 100% ARGON as weld shielding gas.
• Ensure that your torch is set up for aluminum welding:
• The length of the torch cable should not exceed 10’ (it is advisable not to use longer torches).
• Install a teflon wire liner. Follow the instructions for changing the liner.
• Ensure that drive rolls are suitable for aluminum wire.
• Use contact tips that are suitable for aluminum wire and make sure that the diameter of the
contact tip hole corresponds to the wire diameter that is going to be used.
Welding Preparation
General Operating Instructions
Aluminum Welding

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• Always weld clean, dry and well prepared material.
• Hold gun at a 45° angle to the workpiece with nozzle about 1/2” from the surface.
• Move the gun smoothly and steadily as you weld.
• Avoid welding in very drafty areas. A weak, pitted and porous weld will result due to air
blowing away the protective welding gas.
• Keep wire and wire liner clean. Do not use rusty wire.
• Sharp bends or kinks in the welding cable should be avoided.
• Always try to avoid getting particles of metal inside the machine since they could cause short
circuits or other damage.
• Use compressed air to periodically clean the hose liner, especially when changing wire spools.
IMPORTANT: Disconnect from power source when carrying out this operation.
• Using low pressure air (3/5 Bar=20-30 PSI), occasionally blow the dust from the inside of the
welder. This keeps the machine running cooler. Note: do not blow air over the printed circuit
board and electronic components.
• The wire feed roller will eventually wear during normal use. With the correct tension the
pressure roller must feed the wire without slipping. If the pressure roller and the wire feed roller
make contact when the wire is in place between them, the wire feed roller must be replaced.
• Check all cables periodically. They must be in good condition and not cracked.
Welding Hints and Maintenance

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This chart will assist you in resolving common problems you may encounter. These are not all the
possible solutions.
PROBLEM POSSIBLE CAUSE POSSIBLE SOLUTION
No “power” from welder. Input cable or plug malfunction.
Wrong size fuse.
Check for proper input cable
connection.
Check fuse and replace as
necessary.
Fan operates normally, but
when gun trigger pulled,
there is no wire feed, weld
output or gas flow.
Faulty trigger gun.
Thermostat intervention.
Replace torch trigger.
Allow welder to cool. When the
pilot lamp/switch on the front panel
goes dark indicates the thermostat
has closed.
Feed motor operates but
wire will not feed.
Faulty wire feeding motor (rare).
Insufficient feed roller pressure.
Burr on end of wire.
Liner blocked or damaged.
Replace wire feeding motor.
Increase roller pressure.
Re-cut wire square with no burr.
Clear with compressed air or
replace liner.
Lack of penetration. Voltage or wire feed speed too low.
Loose connection inside the
machine (rare).
Worn or wrong size contact tip.
Loose gun connection or faulty gun
assembly.
Wrong size wire.
Torch moved too fast.
Re-adjust the welding parameters.
Clear with compressed air and
tighten all connections.
Replace the contact tip.
Tighten or replace torch.
Use correct size welding wire.
Move the gun smoothly and not too
fast.
Wire is birdnesting at the
drive roller.
Eccessive pressure on drive roller.
Gun liner worn or damaged.
Contact tip clogged or damaged.
Liner stretched or too long.
Adjust pressure on drive roller.
Replace wire liner.
Replace contact tip.
Cut wire liner at the right length.
Troubleshooting

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WWW.FORNEYIND.COM
PROBLEM POSSIBLE CAUSE POSSIBLE SOLUTION
Wire burns back to
contact tip.
Contact tip clogged or damaged.
Wire feed speed too slow.
Wrong size contact tip.
Bad connection from cable to
clamp.
Slag buildup inside nozzle or
nozzle is shorted.
Replace the contact tip.
Increase wire speed.
Use correct size contact tip.
Tighten clamp connection or
replace cable.
Clean or replace nozzle.
Workpiece clamp and/or
cable gets hot.
Wire feed speed too fast. Decrease wire feed speed.
Gun nozzle arcs to work
surface.
Nozzle clogged. Clean or replace nozzle
Wire pushes torch back
from the workpiece.
Torch held too far from the
workpiece.
Hold the torch at the right distance.
Poor quality welds. Insufficient gas at weld area.
Rusty, painted, oil or greasy
workpiece.
Rusty or dirty wire.
Poor gound contact.
Incorrect gas/wire combination
Check that the gas is not being
blown away by drafts and, if so,
move to more sheltered weld area.
If not check gas cylinder contents
gauge, regulator setting and
operation of gas valve.
Ensure workpiece is clean and dry.
Ensure wire is clean and dry.
Check gound clamp/workpiece
connection.
Check the manual for the correct
conbination.
Weld deposit “stringy” and
incomplete.
Torch moved over workpiece too
quickly.
Gas mixture incorrect.
Move the torch slower.
See shielding gas table.
Weld deposit too thick. Torch moved over workpiece too
slowly.
Welding voltage too low.
Move the torch faster.
Increase welding voltage.

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NO. PART NUMBER ITEM DESCRIPTION QTY.
01 21690226K Door latch (1pc pack) 1
02 05000271 Left panel with silk screen and labels 1
03 04600437 Kit spool holder with ring for 5kg spool 1
04
44410068 Wire feeder plast/all d.37 Rul.06-09 1
05 04600145 Motor d.37 + Pinion 1
06 21800051K 4 Lobes d.30 Hand-wheel m8bush 2pcs
pack 2
07 23005501 Mig gun euro connection l=32 1
08 04600114 Kit gas/no gas change board 1
09 04600270 Switch knob d.38 Black 1
10 04600337 Black knob d.38 For potentiom. + Pointer 1
11 04600433 Assembly frame + caps 1
12 21690713 Spacer for plastic frame 1
13 21690805 Torch grommet for euro connection 1
14 22710044 P.C.Board e0592.1R 110v + fuse"csa" 1
15 05000279 Dividing panel with labels 1
16 22400021 Rectifier pms 30b f type 1
17 22900015K Solenoid valve 11va 110v 60hz 1 pc
pack 1
18 05000275 Rear panel 1
19 22910110 Female gas connector 1/8"gas - 5/8"unf 1
20 20220018K 1Pck input cable 3xawg1 4
2,25m+us5/15plug 1
21 21605010K Cable clamp+ring nut, hole d. 20, 2Pcs
pack 2
22 04600054 Complete fansp.16 110V 1
23 21690261 Cable holder 1
Tools and Spare Parts List
NO. PART NUMBER ITEM DESCRIPTION QTY.
24 22210014K Thermostat 100ø 10a1 pc pack 1
25 44120101 Transformer 1ph mig 60hz 115v 40x72
al 1
26 21690225K Plastic hinge for door 20x30 2pcs pack 2
27 22225016 Contactor lx0 110v 10a 4na (cn-11) 1
28 44135123 Choke d.4,3 40X25 al 1
29 33700414
9005 Bottom panel 1
30 22205201 Rotary switch ca20 cm14 1
31
05000267 Front panel 140 mig forney w/silk screen 1
32 22200002K Green on/off switch 16a-250v 1 pc pack 1
33 43210120K Earth cable 10gr.Mmq mt. 2 (Pack.1) 1
34 22110033K Earth clamp 300a zinc-coated 1 pc pack 1
35 05000261 Right cover panel with silk screen 1
36 33740579
9005 Torch wrapper 1
37 21600067 Handle for torch wrapper 1
38
21060152K Flat-key 3x3 l=20 1pc pack 1
39 33805071K Feed roll d.30 0,6-0,9Mm mot2r 1 pc
pack 1
40 33810136 Feed roll secure knob 1
41 23000448 Mig torch 14mm2 3mt tweco 1 euro
connect 1
42 22905101 Gas reducer 2 man. Cga580-5/8"
unf-2b 1
43 30900035 Black gas hose 3 meter 1