Clarke weld MMA/TIG120 Instruction Manual

OPERATION & MAINTENANCE
INSTRUCTIONS
ORIGINAL INSTRUCTIONS GC0722
MMA/TIG INVERTER WELDERS
MODEL NO: MMA/TIG120, 160 & 200
PART NO: 6012100/6012101/6012102

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INTRODUCTION
Thank you for purchasing this CLARKE Welder. Before attempting to operate
the machine it is essential that you read this manual thoroughly and carefully
follow all instructions given. In doing so you will ensure the safety of yourself
and that of others around you, and you can also look forward to the welder
giving you long and satisfactory service.
When unpacking, any damage or deficiency should be reported to your
CLARKE dealer immediately.
PRINCIPLES OF THE MACHINE
Manual Metal Arc (MMA) welding uses a coated consumable electrode
(stick) to lay the weld, therefore an additional welding torch kit is not required.
The arc melts the core of the electrode to produce drops of molten metal
(weld pool) that cool to create the welded joint. Because of the versatility and
simplicity of MMA welding, it requires less skill and is used primarily to weld iron
and steel (including stainless steel. but nickel and copper can also be welded
using this method.
This machine is designed to be used for both metal ARC (MMA) and TIG
welding. (TIG welding leads are not supplied with the machine. These are
however, readily available from your CLARKE dealer (Part number 6012233).
SUITABILITY
MAIN DESIGN FEATURES
MMA/Arc Welding Carbon Steel, Low Alloy Steel, Stainless Steel, Cast
Iron.
TIG Welding Carbon Steel, Low Alloy Steel, Stainless Steel, Cast
Iron, Titanium, Copper + Brass.
ARC-FORCE Automatically increases the current to prevent the
electrode sticking when operating with a short arc
length.
HOT START Increases the welding current at the beginning of
the welding process.
ANTI-STICK The electrode can be easily withdrawn without it
becoming damaged.
VOLTAGE REDUCTION
SAFETY DEVICE (VRD)
Reduces open circuit voltage when not in use to pre-
vent accidental injury

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ENVIRONMENTAL RECYCLING POLICY
Through purchase of this product, the customer is taking on the
obligation to deal with the WEEE in accordance with the WEEE
regulations in relation to the treatment, recycling & recovery and
environmentally sound disposal of the WEEE.
In effect, this means that this product must not be disposed of with general
household waste. It must be disposed of according to the laws governing
Waste Electrical and Electronic Equipment (WEEE) at a recognised disposal
facility.
If disposing of this product or any damaged components, do not dispose of
with general waste. This product contains valuable raw materials. Metal
products should be taken to your local civic amenity site for recycling of metal
products.
SAFETY PRECAUTIONS FOR ALL TYPES OF WELDING
FAILURE TO FOLLOW THESE RULES MAY RESULT IN SERIOUS PERSONAL INJURY.
GENERAL PRECAUTIONS
BURN PREVENTION
Wear protective clothing - gauntlet gloves designed for use in welding, apron,
and protective shoes. Button shirt collar and pocket flaps and wear cuffless
trousers to avoid entry of sparks and slag. Wear helmet with safety goggles or
glasses with side shields underneath, appropriate filter lenses or plates
(protected by clear glass). This is a MUST for welding (and chipping) to protect
the eyes from radiant energy and spatter. Replace cover glass when broken,
pitted, or spattered. Avoid oily or greasy clothing. A spark may ignite them. Hot
metal should never be handled without gloves. First aid facilities and a
qualified first aid person should be available unless medical facilities are close
by for immediate treatment of flash burns of the eyes and skin burns. Ear plugs
should be worn when working overhead or in a confined space. A hard hat
should be worn when others work overhead. Flammable hair preparations
should not be used by persons intending to weld or cut.
NOTE: ALL protective wear incl. masks & head shields MUST comply with
PPE Regulation (EU) 2016/425.
WARNING: AS WITH ALL MACHINERY, THERE ARE CERTAIN HAZARDS
INVOLVED WITH THEIR OPERATION AND USE. EXERCISING RESPECT AND
CAUTION WILL CONSIDERABLY LESSEN THE RISK OF PERSONAL INJURY.
HOWEVER, IF NORMAL SAFETY PRECAUTIONS ARE OVERLOOKED, OR
IGNORED, PERSONAL INJURY TO THE OPERATOR MAY RESULT.

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TOXIC FUME PREVENTION
Severe discomfort, illness or death can result from fumes, vapours, heat, or
oxygen enrichment or depletion that welding (or cutting) may produce.
Prevent them with adequate ventilation. NEVER ventilate with oxygen. Lead-,
cadmium-, zinc-, mercury- and beryllium-, bearing materials, when welded (or
cut) may produce harmful concentrations of toxic fumes. Adequate local
exhaust ventilation must be used, or each person in the area as well as the
operator must wear an air- supplied respirator. For beryllium, both must be
used. Metals coated with or containing materials that emit toxic fumes should
not be heated unless coating is removed from the work surface, the area is
well ventilated, or the operator wears an air-supplied respirator. Work in a
confined space only while it is being force ventilated and, if necessary, while
wearing an air-supplied respirator. Vapours from chlorinated solvents can be
decomposed by the heat of the arc (or flame) to form PHOSGENE, a highly
toxic gas, and other lung and eye irritating by-products. The ultraviolet
(radiant) energy of the arc can also decompose trichloroethylene and
perchloroethylene vapours to form phosgene. DO NOT WELD where solvent
vapours can be drawn into the welding atmosphere or where the radiant
energy can penetrate to atmospheres containing even minute amounts of
trichloroethylene or perchloroethylene.
FIRE AND EXPLOSION PREVENTION
Causes of fire and explosion are:
1. Combustibles reached by the arc, flying sparks, hot slag or heated
material;
2. Short circuits.
BE AWARE that flying sparks or falling slag can pass through cracks, along
pipes, through windows or doors, and through wall or floor openings, out of
sight of the goggled operator.
To prevent fires and explosion: keep equipment clean and operable, free of
oil, grease, and (in electrical parts) of metallic particles that can cause short
circuits. If combustibles are in the area, DO NOT weld. Move the work if
practicable, to an area free of combustibles.
Avoid working in paint spray rooms, dip tanks, storage areas, ventilators. If the
work cannot be moved, move combustibles away from sparks and heat; or
protect against ignition with suitable fire- resistant covers or shields.
Walls, ceilings, and floor near work should be protected by heat resistant
covers or shields. Fire watcher must be standing by with suitable fire
extinguishing equipment during and for some time after welding or cutting if:
1. Appreciable combustibles (including building construction) are within 10m.
2. Appreciable combustibles are further than 10m, but can be ignited by
sparks.

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3. Openings (concealed or visible) in floors or walls can expose combustibles
to sparks.
4. Combustibles adjacent to walls, ceilings, roofs or metal partitions can be
ignited by radiant or conducted heat.
After work, check that area is free of sparks, glowing embers and flames. An
empty container that held combustibles or that can produce flammable or
toxic vapours when heated, must never be welded on or cut, unless the
container has first been cleaned. This includes a thorough steam or caustic
cleaning (or a solvent or water washing, depending on the combustible’s
solubility) followed by purging and inerting with nitrogen or carbon dioxide,
and using protective equipment.
Water filling just below the working level may substitute for inerting.
A container with unknown contents should be cleaned (see paragraph
above). DO NOT depend on sense of smell or sight to determine if it is safe to
weld or cut. Hollow castings or containers must be vented before welding as
they can explode.
In explosive atmospheres, NEVER weld or cut where the air may contain
flammable dust, gas, or liquid vapours.
ELECTRIC ARC WELDING
Comply with precautions in above and this section. Arc welding, properly
done, is a safe process but a careless operator invites trouble. The equipment
carries high currents at significant voltages. The arc is very bright and hot.
Sparks fly, fumes rise, ultraviolet and infrared energy radiates and work pieces
are hot. The wise operator avoids unnecessary risks and protects himself and
others from accidents.
BURN PROTECTION
The welding arc is intense and visibly bright. It’s radiation can damage eyes,
penetrate lightweight clothing, reflect from light coloured surfaces and burn
the skin and eyes. Skin burns resemble acute sunburn, those from gas -
shielded arcs are more severe and painful.
PROTECTIVE CLOTHING (PPE) MUST BE WORN
Wear long sleeved clothing (particularly for gas shielded arc) in addition to
gloves, apron and strong shoes. As necessary, use additional protective
clothing such as leather jacket or sleeves, flameproof apron, and fire-resistant
leggings. Avoid outer garments of untreated cotton. Bare skin protection:
Wear dark substantial clothing, Button collars closed to protect the chest and
neck and button any pockets to prevent entry of sparks.

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EYE AND HEAD PROTECTION
Protect eyes from exposure to arc. NEVER look at an electric arc without
protection. Welding helmet or shield containing an appropriate filter plate
(Please refer to the section ‘Welding Shield on page 12). Place over face
before striking arc. Protect filter plate with a clear cover plate. Cracked or
broken helmet or shield should NOT be worn; radiation can pass through to
cause burns.
Cracked, broken, or loose filter plates must be replaced IMMEDIATELY.
Replace clear cover plate when broken, pitted, or spattered. WE SUGGEST
you wear flash goggles with side shields under the helmet, to give some
protection to the eyes should the helmet not be lowered over the face before
an arc is struck. Looking at an arc momentarily with unprotected eyes
(particularly high intensity gas-shielded arc) can cause a retinal burn that may
leave a permanent dark area in the field of vision. Before welding whilst
wearing contact lenses, seek advice from your optician.
PROTECTION OF NEARBY PERSONNEL
For production welding, a separate, well vented room or enclosed bay is best.
In open areas, surround the operation with low reflective, non- combustible
screens or panels. Allow for free air circulation, particularly at floor level.
Provide face shields for all persons who will be looking directly at the weld.
Others working in the area should wear flash goggles. Before starting to weld,
make sure that screen or bay doors are closed.
TOXIC FUME PREVENTION
Comply with all precautions above.
FIRE AND EXPLOSION PREVENTION
Do not overload arc welding equipment. It may overheat cables and cause a
fire. Loose cable connections may overheat or flash and cause a fire. Never
strike an arc on a cylinder or other pressure vessel. It creates a brittle area that
can cause a violent rupture or lead to such a rupture later under rough
handling.
SHOCK PREVENTION
Exposed live conductors or other bare metal in the welding circuit, or in
unearthed, electrically-LIVE equipment can fatally shock a person whose
body becomes a conductor. DO NOT STAND, SIT, LIE, LEAN ON, OR TOUCH a
wet surface when welding without suitable protection.
PROTECTION FOR WEARERS OF ELECTRONIC LIFE SUPPORT DEVICES
(PACEMAKERS)
Magnetic fields from high currents can affect pacemaker operation. Persons
wearing pacemakers should consult with their doctor before going near arc
welding or spot welding operations.

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PROTECTION AGAINST SHOCK
Keep your body and clothing dry. Never work in damp area without
adequate insulation against electric shock. Stay on a dry duckboard or rubber
mat when dampness or sweat can not be avoided. Sweat, sea water, or
moisture between body and an electrically LIVE part - or earthed metal -
reduces the body surface electrical resistance, enabling dangerous and
possibly lethal currents to flow through the body.
EARTHING THE EQUIPMENT
When arc welding equipment is earthed according to the National Electrical
Code and the workpiece is earthed, a voltage may exist between the
electrode and any conducting object.
Examples of conducting objects include, but are not limited to, buildings,
electrical tools, work benches, welding power source cases, workpieces, etc.
Never touch the electrode and any metal object unless the welding power
source is off. When installing, connect the frames of each unit such as welding
power source, control, work table, and water circulator to the building earth.
Conductors must be adequate to carry earth currents safely. Equipment
made electrically LIVE by stray current may shock, possibly fatally. Do not
EARTH to electrical conduit, or to a pipe carrying ANY gas or a flammable
liquid such as oil or fuel.
CABLES
Frequently inspect cables for wear, cracks and damage. IMMEDIATELY
REPLACE those with excessively worn or damaged insulation to avoid possibly
lethal shock from bared cable. Cables with damaged areas may be taped to
give resistance equivalent to original cable. Keep cable dry, free of oil and
grease and protected from hot metal and sparks.
TERMINALS AND OTHER EXPOSED PARTS
Terminals and other exposed parts of electrical units should have insulating
covers secured before operation.
SAFETY DEVICES
Safety devices such as interlocks and circuit breakers should not be
disconnected or shunted out. Before installation, inspection, or service of
equipment, shut off all power and remove line fuses (or lock or red-tag
switches) to prevent accidental turning ON of power. DO NOT open power
circuit or change polarity while welding. If, in an emergency, it must be
disconnected, guard against shock burns, or flash from switch arcing. Always
shut OFF and disconnect all power to equipment. A power disconnect switch
must be available near the welding power source.

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PREPARATION OF THE WORKING AREA
The working area must be sufficiently spacious, not humid, and well-ventilated
as to avoid any fumes which develop from the welding process and from
incidental material adhering to the pieces to be welded (oils, paints, tars...)
which may cause danger to the operator.
Avoid welding tanks which may contain flammable residuals.
ADDITIONAL PRECAUTIONS FOR MMA WELDING
1. ALWAYS ensure that there is full free air circulating around the outer casing
of the machine and that the louvres are unobstructed.
2. A welding arc can seriously damage your eyes. Both operator and
spectators must ALWAYS use a proper welding face shield or helmet with
suitable filter lenses. Proper gloves and working clothes should be worn at
all times.
3. ALWAYS remove all flammable materials from the welding area.
4. NEVER remove any of the panels unless the machine is disconnected from
the supply and never use the machine with any of the panels removed.
5. NEVER use or store in a damp environment. DO NOT EXPOSE TO RAIN.
6. NEVER attempt any electrical or mechanical repair unless your are a
qualified technician. If you have a problem with the machine contact your
local CLARKE dealer.
7. ALWAYS keep a fire extinguisher handy (Dry Powder, C02 or BCF, NOT
Water).
8. NEVER continue to weld, if, at any time, you feel even the smallest electric
shock. Stop welding IMMEDIATELY and DO NOT attempt to use the
machine until the fault is diagnosed and corrected.
9. NEVER allow the earth cable or torch to become wrapped around the
operator or any person in the vicinity.
WARNING: ELECTRIC SHOCK CAN BE FATAL. A PERSON QUALIFIED IN FIRST
AID SHOULD ALWAYS BE PRESENT IN THE WORKING AREA. IF PERSON IS
UNCONSCIOUS AND ELECTRIC SHOCK IS SUSPECTED, DO NOT TOUCH
THE PERSON IF HE OR SHE IS IN CONTACT WITH THE WELDER OR CABLES.
DISCONNECT THE WELDER FROM THE POWER SOURCE AND THEN USE FIRST
AID. DRY WOOD, OR OTHER INSULATING MATERIAL CAN BE USED TO
MOVE CABLES, IF NECESSARY, AWAY FROM THE PERSON.

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A comprehensive range of CLARKE safety equipment for use when welding is
available from your local dealer. See page 28.
Consideration should be given to shielding the supply cable of permanently
installed welding equipment, in metallic conduit or equivalent. Shielding
should be electrically continuous throughout its length.
The shielding should be connected to the welding power source so that good
electrical contact is maintained between the conduit and the welding power
source enclosure.
The welding equipment should be routinely maintained according to the
manufacturer’s recommendations. All access and service doors and covers
should be closed and properly fastened when the welding equipment is in
operation. The welding equipment should not be modified in any way except
for those changes and adjustments covered in the manufacturer’s
instructions. In particular, the spark gaps of arc striking and stabilizing devices
should be adjusted and maintained according to the manufacturers
recommendations.
SAFETY SYMBOLS
The following symbols may be displayed on the machine.
Read this instruction
booklet carefully
before use.
Do not expose to rain.
Wear welding mask Recycle unwanted
materials under WEEE
Directive
Wear protective gloves General Hazard
Wear a dust mask Warning;- magnetic
field created

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ELECTRICAL CONNECTION (MMA/TIG120 ONLY)
Before switching the product on, make sure that the voltage of your electricity
supply is the same as that indicated on the rating plate. This product is
designed to operate on 230VAC 50Hz. Connecting it to any other power
source may cause damage.
This product may be fitted with a non-rewireable plug. If it is necessary to
change the fuse in the plug, the fuse cover must be refitted. If the fuse cover
becomes lost or damaged, the plug must not be used until a suitable
replacement is obtained.
If the plug has to be changed because it is not suitable for your socket, or due
to damage, it should be cut off and a replacement fitted, following the wiring
instructions shown below. The old plug must be disposed of safely, as insertion
into a mains socket could cause an electrical hazard.
If the colours of the wires in the power cable of this product do not correspond
with the markings on the terminals of your plug, proceed as follows.
•TheBlue wire must be connected to the terminal marked Nor
coloured Black.
•TheBrown wire must be connected to the terminal marked Lor
coloured Red.
•TheYellow and Green wire must be connected to the terminal
marked E or or coloured Green.
.
We strongly recommend that this machine is connected to the mains supply
via a Residual Current Device (RCD). If in any doubt, consult a qualified
electrician. DO NOT attempt any repairs yourself.
WARNING! READ THESE ELECTRICAL SAFETY INSTRUCTIONS
THOROUGHLY BEFORE CONNECTING THE PRODUCT TO THE
MAINS SUPPLY.
Plug must be BS1363/A approved.
Always fit a 13 Amp fuse.
Ensure that the outer sheath of the cable is firmly held by the clamp
Neutral
(Blue)
Live
(Brown)
Earth
(Green and Yellow)

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POWER CONNECTION FOR MMA/TIG160 & 200
CONNECTING TO MAINS POWER
NOTE: These welders are earthed and must only be connected to the
mains with an earth connection. DO NOT attempt to use it without
one.
• These welders will draw far too much power for a normal domestic
230V mains plug and socket and will be supplied fitted with a
32Amp, 3-pin industrial plug.
• A high current 230V mains socket or terminal must be installed by a
qualified and accredited professional electrician. A 32A socket used
with a plug conforming to IEC 60309 is recommended.
• A non-socketed mains connection also requires connection by a
qualified and accredited professional electrician. However, a
socketed connection is safer and is recommended so the welder
can be safely isolated when necessary. If directly wired to the mains,
a double pole, double throw isolator switch must be fitted.
• The welder must be connected using a circuit protected by an RCD.
• Please refer to the Specification for details of the maximum current
required by this welder.
If in any doubt, do not attempt to connect or use this welder until a
professional electrician has been consulted.

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OVERVIEW & INVENTORY
The items supplied include the following:
1. 1 x MMA/TIG Inverter Welder
2. 1 x Electrode Holder
3. 1 x Earth Clamp & Cable
4. 1 x Combination Wire Brush / Hammer
5. 1 x Face Shield
The welder is fitted with
6. Digital display
7. Menu selector button
8. Current /menu selector knob
9. Positive terminal
10. Negative terminal

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ASSEMBLING THE WELDING SHIELD
1. The welding shield shown is
supplied flat for shipping. Fold the
sides of the shield around and clip
to the top panel.
2. Insert both the glass lens panels
into the recess inside the shield.
• The clear glass must be fitted first
to face the outside.
3. Insert the two plastic screws and
use the plastic wingnuts to clamp
the glass panels to the shield.
• The clear glass panel should be
replaced when it becomes badly
pitted.
4. When replacing the glass panels, only use parts supplied by Clarke
International. The dark panel is a certified, optical glass and should not be
exchanged for any other type.
5. Secure the handle in
position using the plastic
nuts provided.
• The handle will be
mounted on the inside of the
shield.

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PREPARATION FOR USE
FITTING THE WELDING ROD
Select the appropriate welding rod and insert it into the welding rod holder.
• It should be approximately the same thickness as the workpieces
being welded.
PREPARING THE WORKPIECE
The area being welded should be perfectly clean. Any coating, plating or
corrosion must be removed, otherwise a good weld will be impossible to
achieve.
PREPARING THE MACHINE
To prepare the machine for welding it is important that you follow the
procedure below.
1. Making sure that the ON/OFF switch, located on the rear panel is in the OFF
position, connect the welding leads as follows:
• Work clamp lead to the (-)
Negative terminal.
• Welding rod holder lead to the
(+) Positive terminal.

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2. Switch ON using the switch
located on the rear panel.
• The digital display on the front
panel will come on and show the
current setting in amps.
• If the machine stops at any time,
the thermal overload device may
have intervened. Wait until the
welder has cooled sufficiently
before restarting work.
3. Select the appropriate welding
rod and fit it into the welding rod
holder.
• When the machine is on, the
menu will display the size of the
electrode fitting to the holder.
The following sizes can be used and are available from your CLARKE dealer.
See also page 28.
4. Attach the work clamp to the workpiece as close as possible to the area
being welded. Clean with a wire brush where necessary to ensure the
connection is as clean as possible.
MACHINE ROD DIAMETER WORKPIECE THICKNESS
MMA/TIG120,160,200 1.6 mm 1.5 - 2.0 mm
MMA/TIG120,160,200 2.5 mm 2.5 - 3.0 mm
MMA/TIG120,160,200 3.2 mm 3.5 - 4.5 mm
MMA/TIG160 & 200 4.0 mm 5.0 - 8.0 mm

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5. Press the menu button to select
MMA welding mode.
• The current can be adjusted in this
mode to match the material
being welded.
• To select the parameter use the
menu to cycle between function.
6. Press the menu button to select
Anti-Stick mode and switch it on
or off by pressing the MENU
control and turning the control
knob.
7. Set the required current using the
current selector knob.
• With practice you will gain a feel
for the correct current setting for
different welding rod thicknesses.
• The “Hot Start” function will be
enabled which delivers a high
current when striking the arc to
prevent the rod from sticking.
• “Arc Force” will deliver a
temporary increase in output current during welding when the arc is too
short. This assists with welding by giving a consistent arc delivery to
compensate for the positioning of the rod.

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VOLTAGE REDUCTION DEVICE (VRD)
The VRD is a safety feature that It is also known as “Anti-shock”. It’s function is
to lower the open circuit voltage across the output terminals to a safe 12V
when the welder is not in use.
As soon as the welder is used (a load
of 200 ohms or less is detected), the
voltage will increase to the full output
to enable welding to commence.
The “VRD” will only turn the output of
the welder back to a reduced output
state of 12 volts once the electrode Is
removed from the work piece or if
the resistance across the output rises
above 200 ohms.
If you wish to turn off this feature, set the VRD option on the menu panel to OFF
by pressing the MENU control and turning the control knob. We recommend
that you leave it switched ON.

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ARC WELDING
The consumable electrode is connected to a high amperage low voltage
supply which creates an electric arc between the electrode and the
workpiece.
Benefits over TIG welding include less experience needed and torch kit or
shielding gas are not required.
The most difficult aspect of the arc welding process, particularly for beginners,
is that of striking an arc. We strongly recommend that you practice on some
pieces of scrap metal to get the feel of the operation before you start an
actual welding job.
1. Holding the welding mask close-up to your face, give a short stroke with
the electrode on the workpiece. As soon as the arc is primed, withdraw the
electrode from the workpiece to leave a gap. The current will flow across
the gap with a crackling noise and a brilliant arc. Continue to weld in one
direction, maintaining the small gap as you go.
2. As soon as the arc is struck, maintain a distance from the workpiece equal
to the diameter of the electrode. Keep this distance as constant as
possible for the duration of the weld. As you advance along the workpiece
the angle of the electrode must be maintained at between 20º and 30º.
NOTE: When you prime the arc be sure to withdraw the electrode swiftly
to leave the gap, otherwise the electrode will weld itself to the
workpiece. If this occurs give the electrode a short sharp jerk to
free it and, if necessary, prime the arc again. If you cannot free
the electrode, switch the machine off immediately and free it.
Take care the electrode will get red hot very quickly and will be
capable of burning through welding gloves.
WARNING: WHEN WELDING ALWAYS ENSURE THERE IS ADEQUATE
VENTILATION IN THE WORK AREA AS THE WELDING PROCESS GIVES OFF
TOXIC FUMES.
WARNING: DO NOT STRIKE THE ELECTRODE ON THE WORKPIECE, AS THIS
MAY DAMAGE THE ELECTRODE.
WARNING: WELDING ARCS PRODUCE HARMFUL UV/IR LIGHT WHICH CAN
SERIOUSLY DAMAGE YOUR EYES. ALWAYS USE A WELDING FACE-SHIELD
WITH A SUITABLE FILTER THAT CONFORMS TO CURRENT STANDARDS.
WARNING: NEVER LOOK AT THE ARC WITHOUT A SUITABLE WELDING
FACE-SHIELD
WARNING: PROTECT BYSTANDERS BY USING WELDING SCREENS/
CURTAINS.

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3. At the finish of the weld, bring the end of the electrode backward in order
to fill the weld crater and then quickly lift the electrode from the weld pool
to extinguish the arc.
4. Inspect the job carefully. Any slag forming on the surface should be
chipped away with a chipping hammer or pick. ALWAYS wear your safety
goggles when chipping away slag.
TIG WELDING
TIG welding is primarily for very thin materials. It uses a non-consumable
tungsten (or tungsten alloy) electrode, held in a torch.
A shielding gas (100% Argon), is fed through the torch to protect:
• The electrode,
• Molten weld pool,
• Solidifying weld metal from contamination by the atmosphere.
The electric arc is produced by the passage of current through the
conductive, ionized shielding gas. The arc is established between the tip of the
electrode and the work. Heat generated by the arc melts the base metal.
Once the arc and weld pool are established, the torch is moved along the
joint and the arc progressively melts the joined surfaces. Filler wire, if used, is
usually added to the leading edge of the weld pool to fill the joint.
This process is ideally suited for welding thin metals such as car body panels,
pressure vessels, heat exchangers, pipes etc., where accuracy and a high
quality weld is desired, as it produces a very low porosity weld.
MAIN FEATURES OF TIG WELDING
1. Electronic control of welding current.
2. Forced air cooling.
3. A thermal overload protection device prevents overheating.
TIG WELDING PROCESS ADVANTAGES
• It produces superior quality welds, generally free of defects.
• It is free of the spatter which occurs with other arc welding processes.
• It can be used with or without filler metal as required.
• It allows excellent control of root pass weld penetration.
• It can produce welds at high speeds.
• It allows precise control of the welding variables.

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• It is capable of welding very thin material (0.5mm), without undue
distortion.
LIMITATIONS
1. Greater weld dexterity is required.
2. These units have a DC output which is not suitable for welding aluminium.
TIG WELDING
• The machine is not equipped with a TIG welding torch and cables;
these are available from your Clarke dealer (Part number 6012232).
• Additionally, before TIG welding, you must obtain a gas cylinder of
100% pure Argon.
To prepare the unit for TIG welding, it is important that you adopt the following
procedure.
1. Plug the work clamp lead in to the +ve terminal, and secure the work
clamp to the workpiece.
• For good contact, the work clamp must be attached to clean bare
metal. Clean with a wire brush where necessary.
2. Plug the torch lead to the -ve terminal.
3. Screw the pressure regulator on to
the gas bottle tightly, and attach
the gas hose to the inlet connector
securely, with a hose clip.
4. Turn the pressure regulator knob to
set a pressure of approx. 2.5kg/
cm2(35 lbf/in2).
5. Ensure the electrode at the torch
nozzle, protrudes by 4 - 5mm, also
ensure that the electrode is sharply
pointed with an angle of 40°-60°, if
it is not, grind it to shape. (Consult
your TIG Torch manual for the
procedure for adjusting the
electrode).
6. Set the welding current in
accordance with the thickness of
the material to be welded and the
size of tungsten electrode to be
used, (See page 14).