Jasic TIG Series User manual

2
Your new product
Thank you for selecng this Jasic product.
This product manual has been designed to ensure that you get the most from your new product. Please
ensure that you are fully conversant with the informaon provided paying parcular aenon to the
safety precauons. The informaon will help protect yourself and others against the potenal hazards
that you may come across.
Please ensure that you carry out daily and periodic maintenance checks to ensure years of reliable and
trouble free operaon.
Please call your Jasic distributor in the unlikely event of a problem occurring.
Please record below the details from your product as these will be required for warranty purposes and to
ensure you get the correct informaon should you require assistance or spare parts.
Date purchased ________________________________________
From where ________________________________________
Serial number ________________________________________
(The serial number is normally located on the top or underside of the machine and will begin with AA)
For further informaon on your Jasic product warranty registraon please visit:
www.jasic-warranty.co.uk
Disclaimer
Whilst every eort has been made to ensure that the informaon contained within this manual is
complete and accurate, no liability can be accepted for any errors or omissions.
Please note:
Products are subject to connual development and may be subject to change without noce.
Regularly check our product pages at www.Jasic.co.uk for revision updated operang manuals.
No part of this manual may be copied or reproduced by any means without the wrien permission of
Wilkinson Star Limited.

3
CONTENTS
Index Page
Your New Product 2
Index 3
Safety Instrucon 4
General electrical safety 4
General operang safety 4
PPE 5
Welding processes lens shade selector guide 5
Fume and welding gases 6
Fire risks 6
The working environment 7
Protecon from moving parts 7
Magnec elds 7
Compressed gas cylinders and regulators 7
RF declaraon 8
LF declaraon 8
Materials and their disposal 8
Product Overview 9
Technical Specicaons 10
Descripon of Controls 11
Installaon 12
Operaon MMA 14
Operaon TIG 15
Guide to MMA Welding 16
MMA Welding Problems 20
Guide to TIG Welding 21
TIG Welding Torch 26
Tig Welding Problems 27
Maintenance 29
Service Schedule Record 29
Troubleshoong 30
EC Declaraon of Conformity 31
WEEE Disposal 31
RoHS Compliance Declaraon 31
Statement of Warranty 32
Schemac 33
Opons and Accessories 34
Notes 35
Jasic Contact Details 36

4
SAFETY INSTRUCTION
These general safety norms cover both arc welding machines and plasma cung machines unless
otherwise noted.
It is important that users of this equipment protect yourselves and others from harm or even death.
The equipment must only be used for the purpose it was designed for. Using it in any other way could
result in damage or injury and in breach of the safety rules.
Only suitably trained and competent persons should use the equipment.
Pacemaker wearers should consult your doctor prior to using this equipment.
PPE and workplace safety equipment must be compable for the applicaon of work involved.
Always carry out a risk assessment before undertaking any welding or cung acvity
General electrical safety
The equipment should be installed by a qualied person and in accordance with current
standards in accordance with current standards in operaon. It is the users responsibility
to ensure that the equipment is connected to a suitable power supply. Consult with your
ulity supplier if required. Do not use the equipment with the covers removed.
Do not touch live electrical parts or parts which are electrically charged.
Turn o all equipment when not in use.
In the case of abnormal behaviour of the equipment, the equipment should be checked by a suitably
qualied service engineer.
If earth bonding of the work piece is required, bond it directly with a separate cable with a current
carrying capacity capable of carrying the maximum capacity of the machine current.
Cables (both primary supply and welding) should be regularly checked for damage and overheang.
Never use worn, damaged, under sized or poorly jointed cables.
Insulate yourself from work and earth using dry insulang mats or covers big enough to prevent any
physical contact.
Never touch the electrode if you are in contact with the work piece return.
Do not wrap cables over your body.
Ensure that you take addional safety precauons when you are welding in electrically hazardous
condions such as damp environments, wearing wet clothing and metal structures.
Try to avoid welding in cramped or restricted posions.
Ensure that the equipment is well maintained. Repair or replace damaged or defecve parts immediately.
Carry out any regular maintenance in accordance with the manufacturers instrucons.
The EMC classicaon of this product is class A in accordance with electromagnec compability
standards CISPR 11 and IEC 60974-10 and therefore the product is designed to be used in industrial
environment only.
WARNING: This class A equipment is not intended for use in residenal locaons where the electrical
power is provided by a public low-voltage supply system. In those locaons it may be dicult to ensure
the electromagnec compability due to conducted and radiated disturbances.
General operang safety
Never carry the equipment or suspend it by the carrying strap or handles during welding.
Never pull or li the machine by the welding torch or other cables. Always use the correct li points or
handles. Always use the transport under gear as recommended by the manufacturer.
Never li a machine with the gas cylinder mounted on it.
If the operang environment is classied as dangerous, only use S-marked welding equipment with a safe
idle voltage level. Such environments may be for example: humid, hot or restricted accessibility spaces.

5
SAFETY INSTRUCTION
Use of Personal Protecve Equipment (PPE)
Welding arc rays from all welding processes produce intense, visible and invisible (ultraviolet and
infrared) rays that can burn eyes and skin.
• Wear an approved welding helmet ed with an appropriate shade of
lter lens to protect your face and eyes when welding or watching.
• Wear approved safety glasses with side shields under your helmet.
• Never use broken or faulty welding helmets.
• Always ensure there are adequate protecve screens or barriers to
protect others from ash, glare and sparks from the welding area.
• Ensure that there are adequate warnings that welding or cung is
taking place.
• Wear suitable protecve ame resistant clothing, gloves and footwear.
• Check and be sure the area is safe and clear of inammable material
before carrying out any welding.
Some welding and cung operaons may produce noise. Wear safety ear
protecon to protect your hearing if the ambient noise level exceeds the
local allowable limit (e.g: 85 dB).
Welding and Cung Lens Shade Selector Guide

6
SAFETY INSTRUCTION
Safety against fumes and welding gases
The HSE have idened welders as being an ‘at risk’ group for occupaonal diseases arising
from exposure to dusts, gases, vapours and welding fumes. The main idened health eects
are pneumonia, asthma, chronic obstrucve pulmonary disease (COPD), lung and kidney
cancer, metal fume fever (MFF) and lung funcon changes.
During welding and hot cung ‘hot work’ operaons, fumes are produced which are
collecvely known as welding fume. Depending upon the type of welding process being performed, the
resultant fume generated is a complex and highly variable mixture of gases and parculates.
Regardless of the length of welding being carried out, all welding fume, including mild steel welding
requires suitable engineering controls to be in place which is
usually Local Exhaust Venlaon (LEV) extracon to reduce the
exposure to welding fume indoors and where LEV does not
adequately control exposure it should also be enhanced by using
suitable respiratory protecve equipment (RPE) to assist with
protecng against residual fume.
When welding outdoors appropriate RPE should be used.
Prior to undertaking any welding tasks an appropriate risk
assessment should be carried out to ensure expected control
measures are in place.
Locate the equipment in a well-venlated posion and keep
your head out of the welding fume.
Do not breathe the welding fume.
Ensure the welding zone is well-venlated and provision should be made for suitable local fume
extracon system to be in place.
If venlaon is poor, wear an approved airfed welding helmet or respirator.
Read and understand the Material Safety Data Sheets (MSDS’s) and the manufacturer’s instrucons for
metals, consumable, coangs, cleaners and de-greasers.
Do not weld in locaons near any de-greasing, cleaning or spraying operaons.
Be aware that heat and rays of the arc can react with vapours to form highly toxic and irritang gases.
For further informaon please refer to the HSE website www.hse.gov.uk for related documentaon.
Precauons against re and explosion
Avoid causing res due to sparks and hot waste or molten metal.
Ensure that appropriate re safety devices are available near the
welding and cung area.
Remove all ammable and combusble materials from the welding,
cung and surrounding areas.
Do not weld or cut fuel and lubricant containers, even if empty. These must be
carefully cleaned before they can be welded or cut.
Always allow the welded or cut material to cool before touching it or placing it in
contact with combusble or ammable material.
Do not work in atmospheres with high concentraons of combusble fumes, ammable gases and dust.
Always check the work area half an hour aer cung to make sure that no res have begun.
Take care to avoid accidental contact of electrode to metal objects. This could cause arcs, explosion,
overheang or re.
Understand your re exnguishers
An example of personal fume protection

7
SAFETY INSTRUCTION
The Working environment
Ensure the machine is mounted in a safe and stable posion allowing for cooling air circulaon.
Do not operate equipment in an environment outside the laid down operang parameters.
The welding power source is not suitable for use in rain or snow.
Always store the machine in a clean, dry space.
Ensure the equipment is kept clean from dust build up.
Always use the machine in an upright posion.
Protecon from moving parts
When the machine is in operaon keep away from moving parts such as motors and fans.
Moving parts, such as the fan, may cut ngers and hands and snag garments.
Protecons and coverings may be removed for maintenance and controls only by qualied personnel
aer rst disconnecng the power supply cable.
Replace the coverings and protecons and close all doors when the intervenon is nished and before
starng the equipment.
Take care to avoid geng ngers trapped when loading and feeding wire during set up and operaon.
When feeding wire be careful to avoid poinng it at other people or towards your body.
Always ensure machine covers and protecve devices are in operaon.
Risks due to magnec elds
The magnec elds created by high currents may aect the operaon of pacemakers or elec-
tronically
controlled medical equipment.
Wearers of vital electronic equipment should consult their physician before beginning any arc
welding, cung, gouging or spot welding operaons.
Do not go near welding equipment with any sensive electronic equipment as the magnec elds may
cause damage.
Keep the torch cable and work return cable as close to each other as possible throughout their length.
This can help minimise your exposure to harmful magnec elds.
Do not wrap the cables around the body.
Handling of compressed gas cylinders and regulators
Mishandling gas cylinders can lead to rupture and the release of high pressure gas.
Always check the gas cylinder is the correct type for the welding to be carried out.
Always store and use cylinders in an upright and secure posion.
All cylinders and pressure regulators used in welding operaons should be handled with care.
Never allow the electrode, electrode holder or any other electrically “hot” parts to touch a cylinder.
Keep your head and face away from the cylinder valve outlet when opening the cylinder valve.
Always secure the cylinder safely and never move with regulator and hoses connected.
Use a suitable trolley for moving cylinders.
Regularly check all connecons and joints for leaks.
Full and empty cylinders should be stored separately.
Never deface or alter any cylinder

8
SAFETY INSTRUCTION
RF Declaraon
Equipment that complies with direcve 2014/30/EU concerning electromagnec compability (EMC)
and the technical requirements of EN60974-10 is designed for use in industrial buildings and not those
for domesc use where electricity is provided via the low voltage public distribuon system.
Dicules may arise in assuring class A electromagnec compability for systems installed in domesc
locaons due to conducted and radiated emissions.
In the case of electromagnec problems, it is the responsibility of the user to resolve the situaon.
It may be necessary to shield the equipment and t suitable lters on the mains supply.
LF Declaraon
Consult the data plate on the equipment for the power supply requirements.
Due to the elevated absorbance of the primary current from the power supply network, high power
systems aect the quality of power provided by the network. Consequently, connecon restricons or
maximum impedance requirements permied by the network at the public network connecon point
must be applied to these systems.
In this case, the installer or the user is responsible for ensuring the equipment can be connected,
consulng the electricity provider if necessary.
Materials and their disposal
Welding equipment is manufactured with BSI published standards meeng CE requirements materials
which do not contain any toxic or poisonous materials dangerous to the operator.
Do not dispose of the equipment with normal waste. The European Direcve 2012/19/EU on Waste
Electrical and Electronic Equipment states the electrical equipment that has reached its end of life must
be collected separately and returned to an environmentally compable recycling facility for disposal.
For more detailed informaon please refer to the HSE website www.hse.gov.uk

9
PRODUCT OVERVIEW
The Jasic TIG inverter range of welding machines have been designed as integrated and portable
welding power supply units incorporang the most advanced IGBT inverter technology in power
electronics with easy operaon and adjustment due to friendly user interface.
Unique electric structure and air channel design in this series of machines can speed up the heat
dissipaon of the power device as well as improving the duty cycles of the machines. The unique heat
rejecon eciency of the air channel can eecvely prevent the power devices and control circuits from
being damaged by the dust absorbed by the fan and thereby, the reliability of the machine is greatly
improved.
The enre machine is in form of coherent streamline, the front and rear panels are naturally integrated
via large-radian transion manner. The front panel and the rear panel of the machine and the handle are
coated with rubber oil, so the machine has so texture, good hand feeling that feels warm and
comfortable to hold.
Jasic TIG 180 and 200 Product Features:
• Compact size, lightweight and modern design
• 180DV has dual voltage inputs of 115V and 230V
• DC TIG with excellent HF arc ignion which oers reduced
interference and high reliability
• Suitable for a wide range of DC MMA welding electrodes
• Advanced IGBT inverter technology
• 40Khz inverter frequency, high eciency
• Downslope in TIG mode with post ow gas funcon
• Built in hot start arc ignion funcon which ensures excellent arc ignion
• Built in self adapve arc force technology which maintains the opmum MMA arc condions during
operaon even with long welding cables
• Excellent weld characteriscs
• Auto compensaon for mains voltage uctuaon
• Easy arc starng, low spaer, stable current which oers good weld bead shape
• High quality tacle nish to mouldings and handle
• Supplied with 12’ TIG Torch Model TIG37ERGO, Gas regulator, Gas hose, Work return lead and clamp

10
TECHNICAL SPECIFICATIONS
Please Note
Due to variaons in manufactured products all claimed performance rangs, capacies, measurements,
dimensions and weights quoted are approximate only. Achievable performance and rangs when in use
can depend upon correct installaon, applicaons and use along with regular maintenance and service.
Parameter Jasic TIG 180 DCUnit Jasic TIG 180 DC DV Jasic TIG 200 DC
Rated input voltage -
AC230V±15% 50/60Hz
VAC115V±15% 50/60Hz
AC230V±15% 50/60Hz
-
AC230V±15% 50/60Hz
Rated input power -
7.1
kVA 115V - 4
230V - 7
-
8.2
Rated input current Imax 31A35.6 35.6
Rated input current Ie -
16.5
A115V - 18.5
230V - 14.2
-
18.9
Welding current range
-
-
TIG 10 ~ 180
MMA 10 ~ 160
A
115V - TIG 10 ~ 120
115V - MMA 10 ~ 100
230V - TIG 10 ~ 180
230V - MMA 10 ~ 160
-
-
TIG 10 ~ 200
MMA 10 ~ 180
No-load voltage 65V65 65
Rated duty cycle (40°C)
-
-
TIG 180A @ 35%
MMA 160A @ 35%
%
115V - TIG 120A @ 35%
115V - MMA 100A @ 35%
230V - TIG 180A @ 40%
230V - MMA 160A @ 40%
-
-
TIG 200A @ 35%
MMA 180A @ 35%
Downslope me S0 ~ 10 0 ~ 10 0 ~ 10
Post gas me S0 ~ 15 0 ~ 15 0 ~ 15
Arc ignion type - HF HF HF
Eciency 85%85 85
Power factor 0.7cosφ0.7 0.7
Standard - EN60974-1EN60974-1EN60974-1
Protecon class IP21SIP IP21S IP21S
Insulaon class F- FF
Noise Db <70 <70 <70
Operang temperature °C -10 ~ +40 -10 ~ +40 -10 ~ +40
Storage temperature °C -25 ~ +55 -25 ~ +55 -25 ~ +55
Overall size 365 x 135 x 277 mm 365 x 135 x 277 365 x 135 x 277
Weight 5.94Kg 5.94 6.12

11
CONTROLS
Front view Jasic TIG 180 & 200
1. Overheang LED: Indicates overheang, when this LED
is on it indicates that the temperature inside the
machine is too high and the machine is under
overheang protecon status
2. Power LED: Indicates that power is present at the
machine and that the power switch of the machine
is on
3. Downslope me control: 1~10s
4. Post ow me control: 1~10s
5. "+" Output terminal*: To connect the work clamp
6. "-" Output terminal*: To connect the TIG torch
7. Gas terminal: To connect the gas hose of the TIG torch
8. Control terminal: To connect the trigger switch plug
of the TIG torch trigger
9. Front grill for air intake
10. MMA/TIG switch: To toggle between MMA and TIG
11. 2T/4T switch: When the toggle switch is switched to 4T, self-lock funcon is available
12. Welding current knob: To adjust the output current
* Panel socket size is 35/50mm
Rear view Jasic TIG 180 & 200
13. Gas inlet connector
14. Power ON/OFF switch
15. Mains power cable
16. Rear panel grill and cooling fan
13

12
INSTALLATION
Unpacking
Check the packaging for any signs of damage.
Carefully remove the machine and retain the packaging unl the installaon is complete.
Locaon
The machine should be located in a suitable posion and environment. Care should be taken to avoid
moisture, dust, steam, oil or corrosive gases.
Place on a secure level surface and ensure that there is adequate clearance around the machine to
ensure natural airow.
Input connecon
Before connecng the machine you should ensure that the correct supply is available.
Details of the machine requirements can be found on the data plate of the machine or in the technical
parameters shown in the manual.
The equipment should be connected by a suitably qualied competent person. Always ensure the
equipment has a proper grounding.
Never connect the machine to the mains supply with the panels removed.
Output connecons
Electrode polarity
In general when using manual arc welding electrodes the electrode holder is connected to the posive
terminal and the work return to the negave terminal.
"+" output terminal: For MMA connect the electrode holder
"-" output terminal: For MMA connect the work return lead
Always consult the electrode manufacturer’s data sheet if you have any doubts.
When using the machine for TIG welding the TIG torch should be connected to the negave terminal and
the work return to the posive terminal.
"+" output terminal: For TIG connect the work return lead
"-" output terminal: For TIG connect the TIG torch
Gas connecons
Connect the gas hose to the regulator/owmeter located on the shield gas cylinder and connect the
other end to the machine.
Please Note:
Check these power
connecons daily to
ensure they have not
become loose otherwise
arcing may occur when
used under load.
Generic library picture

13
INSTALLATION
MMA welding
Insert the cable plug with electrode holder into the “+” socket on the front panel of the welding machine
and ghten it clockwise.
Insert the cable plug of the work return lead into the “-” socket on the front panel of the welding machine
and ghten it clockwise. Example shown below:
TIG welding
Insert the cable plug with the work clamp into the “+” socket on the front panel of the welding machine
and ghten it clockwise.
Insert the cables plug of the TIG torch into the “-” socket on the front panel of the machine and ghten
clockwise. Connect the gas quick connector into the outlet on the machine front.
Connect the torch switch plug into the socket on the front panel. Example shown below:
Connect the gas hose to the regulator/owmeter located on the shield gas cylinder and connect the
other end to the machine.
Before starng any welding acvity ensure that you have suitable eye protecon, protecve clothing
and all required PPE. Also take the necessary steps to protect any persons within the area.

14
OPERATION—MMA
Before starng any welding acvity ensure that you have suitable eye protecon and
protecve clothing. Also take the necessary steps to protect any persons within the welding
area.
MMA welding mode
MMA (Manual Metal Arc), SMAW (Shielded Metal Arc Welding) or just Sck Welding.
Sck welding is an arc welding process which melts
and joins metals by heang them with an arc
between a covered metal electrode and the work.
Shielding is obtained from the electrode outer
coang, oen called ux. Filler metal is primarily
obtained from the electrode core.
The electrodes outer coang called ux assists in
creang the arc and provides a shielding gas and
on cooling forms a slag covering to protect the
weld from contaminaon.
When the electrode is moved along the work piece
at the correct speed the metal core deposits a uniformed layer called the weld bead.
Aer connecng the welding leads as
detailed you will need to switch the
power switch on the back panel to “ON”,
the machines power LED comes on and
the fan is working.
Select MMA by switching to the MMA
welding mode. There is voltage output
at both output terminals.
Ensure you check that you have the
electrode polarity correct.
Set the amperage on the machine
suitable for the electrode being used.
Please see the guide below to amperages required, although this MMA welding electrode guide can vary
depending on material, work piece thickness, welding posion and joint form.
Electrode Diameter
(mm)
Recommended Welding
Current (A)
Recommended Welding
Voltage (V)
1.0 20 ~ 60 20.8 ~ 22.4
1.6 44 ~ 84 21.76 ~ 23.46
2.0 60 ~ 100 22.4 ~ 24
2.5 80 ~ 120 23.2 ~ 24.8
3.2 108 ~ 148 24.32 ~ 24.92
4.0 140 ~ 180 24.6 ~ 27.2

15
OPERATION—TIG
Before starng any welding acvity ensure that you have suitable eye protecon and
protecve clothing. Also take the necessary steps to protect any persons within the welding
area.
TIG welding mode
Terms used: TIG – Tungsten Inert Gas, GTAW – Gas Tungsten Arc Welding.
TIG welding is an arc welding process that uses a non-consumable
tungsten electrode to produce the heat for welding.
The weld area is protected from atmospheric contaminaon by a
shielding gas (usually an inert gas such as argon or helium) and a
ller rod matching the base material is normally used, though
some welds, known as autogenous welds, are carried out without
the need for ller wire.
TIG Process can be either DC or AC modes:
DC - Direct current for welding steel, stainless steel, copper etc.
AC - Alternang current for welding aluminium and it’s alloys.
Connect the TIG torch leads as shown.
Ensure that a suitable inert gas supply is
connected.
Switch the power switch on the back panel to
“ON” the machine is started with the power
LED on and the fan working.
Switch the MMA/TIG switch to TIG mode.
Open the gas valve of the cylinder and adjust
the gas regulator to obtain the desired ow
rate.
Press the torch trigger briey, the solenoid valve will operate and gas will ow.
Adjust the welding current according to the thickness of the work piece to be welded (for a guide to
welding parameters, please refer to the table below).
Hold the torch 2-4mm away from the work piece then press the torch trigger. Aer the arc is ignited, the
HF discharge will cease, the current will maintain the preset value and welding can be carried out.
Aer releasing the torch trigger, the welding arc
stops but gas connues owing for the post ow
me and welding ends.
Adjust the downslope me potenometer to
change the me according to the welding
process requirements.
The amperage guide for TIG welding tungsten
sizes can vary depending on material, work
piece thickness, welding posion and joint form.
Tungsten Size DC – Electrode Negave
1.0mm 15 – 80A
1.6mm 70 – 150A
2.4mm 150 – 250A
3.2mm 250A – 400A
4.0mm 400A – 500A
6.0mm 750A – 1000A

16
GUIDE TO MMA WELDING
Before starng any welding acvity ensure that you have suitable eye protecon and
protecve clothing. Also take the necessary steps to protect any persons within the welding
area.
Notes for the welding beginner
This secon is designed to give the beginner who has not previously done any welding some informaon
to get them going. The simplest way to start is to pracce by running weld beads on a piece of scrap plate.
Start by using mild steel (paint free) plate of 6.0mm thick and using 3.2mm electrodes. Clean any grease,
oil and loose scale from the plate and x rmly to your work bench so that welding can be carried out.
Make sure that the work return clamp is secure and making good electrical contact with the mild steel
plate, either directly or through the work table. For best results always clamp the work lead directly to
the material being welded, otherwise you may experience a poor electrical circuit.
Welding posion
When welding, ensure you place yourself in a comfortable posion for welding and your welding
applicaon before you begin to weld. This maybe by sing at a suitable height which oen is the best
way to weld ensuring you’re relaxed and not tense. A relaxed posture will ensure the welding task
becomes much easier.
Please ensure you always wear suitable PPE and use suitable fume extracon when welding.
Place the work so that the direcon of welding is across, rather than to or from your body. The electrode
holder lead should always be clear of any obstrucon so that you can move your arm freely along as the
electrode burns down. Some elders prefer to have the welding lead over their shoulder, this allows
greater freedom of movement and can reduce the weight from your hand.
Always inspect your welding equipment, welding cables and electrode holder before each use to ensure
it’s not faulty or worn as you may be at risk of an electric shock.
MMA process features and benets
The versality of the process and the skill level required to learn, basic simplicity of the equipment make
the MMA process one of the most common used throughout the world.
The MMA process can be used to weld a wide variety of materials and is normally used in the horizontal
posion but can be used in vercal or overhead with the correct selecon of electrode and current. In
addion, it can be used to weld at long distances from the power source subject to the correct cable
sizing. The self shielding eect of the electrode coang makes the process suitable for welding in
external environments. It is the dominant process used in maintenance and repair industries and is used
extensively in structural and fabricaon work.
The process is well able to cope with less than ideal material condions such as dirty or rusty material.
Disadvantages of the process are the short welds, slag removal and stop/starts which lead to poor weld
eciency which is in the region of 25%. The weld quality is also highly dependent on the skill of the
operator and many welding problems can exist.

17
GUIDE TO MMA WELDING
Before starng any welding acvity ensure that you have suitable eye protecon and
protecve clothing. Also take the necessary steps to protect any persons within the welding
area.
MMA process ps and guides
Typical welder set up
1. Electrode holder
2. Work return clamp
3. Work piece
4. Weld material covered
by electrode ux or slag
5. Electrode
6. Distance from work to
electrode (arc Length)
Welding current will ow in the circuit as soon as the electrode contacts the work piece. The welder
should always ensure a good connecon of the work clamp. The nearer the clamp is placed to the
welding area the beer.
When the arc is struck the distance between the end of the electrode and the work will determine the
arc voltage and also aect the weld characterisc. As a guide the arc length for electrodes up to 3.2mm
diameter should be around 1.6mm and over 3.2mm around 3mm.
Upon compleon of the weld the welding ux or slag will need to be removed usually with a chipping
hammer and wire brush.
Joint form in MMA
In MMA welding, the common basic joint forms: bu joint, corner joint, lap joint & T joint.

18
GUIDE TO MMA WELDING
Before starng any welding acvity ensure that you have suitable eye protecon and
protecve clothing. Also take the necessary steps to protect any persons within the welding
area.
MMA arc striking
Tap technique - Li the electrode upright and bring it down to strike the work piece. Aer forming short
circuit, quickly li up about 2~4mm and arc will be ignited. This method is dicult to master.
Scratch technique - Drag the electrode and scratch the work piece as if striking a match. Scratching the
electrode may cause the arc to burn along the scratch path, so care should be taken to scratch in the weld
zone. When the arc is struck adopt the correct welding posion.
Electrode posioning
Horizontal or at posion
The electrode should be posioned at right angles to the plate and inclined in the direcon of travel at
around 10º-30º.

19
GUIDE TO MMA WELDING
Before starng any welding acvity ensure that you have suitable eye protecon and
protecve clothing. Also take the necessary steps to protect any persons within the welding
area.
Fillet welding
The electrode should be posioned to split the angle i.e. 45º. Again the electrode should be inclined in the
direcon of travel at around 10º-30º.
Manipulaon of electrode
In MMA welding there are three
moons used at the end of electrode:
1. The electrode feeding to the
molten pool along axis
2. The electrode swing right and le
3. The electrode moving in the weld
direcon
The operator can choose the manipulaon of electrode based on welding joint, welding posion,
electrode spec, welding current and operaon skill etc.
Weld characteriscs
A good weld bead should exhibit the following characteriscs:
1. Uniform weld bead
2. Good penetraon into the base material
3. No overlap
4. Fine spaer level
A poor weld bead should exhibit the following characteriscs:
1. Uneven and errac bead
2. Poor penetraon into the base material
3. Bad overlap
4. Excessive spaer levels
5. Weld crater

20
MMA WELDING PROBLEMS
Before starng any welding acvity ensure that you have suitable eye protecon and
protecve clothing. Also take the necessary steps to protect any persons within the welding
area.
Arc welding defects and prevenon methods
Defect Possible cause Acon
Excessive spaer (beads of metal
scaered around the weld area)
Amperage too high for the
selected electrode
Reduce amperage or ulise larger
diameter electrode
Voltage too high or arc length
too long
Reduce arc length or voltage
Uneven and errac weld bead and
direcon
Weld bead is inconsistent and
misses joint due to operator
Operator training required
Lack of penetraon – The weld bead
fails to create complete fusion
between material to be welded,
oen surface appears okay but weld
depth is shallow
Poor joint preparaon
Insucient heat input
Poor weld technique
Joint design must allow for full access
to the root of the weld
Material too thick
Increase the amperage or
increase the electrode size
and amperage
Reduce travel speed
Ensure the arc is on the leading edge of
the weld puddle
Porosity – Small holes or cavies on
the surface or within the weld
material
Work piece dirty
Electrode is damp
Arc length is excessive
Remove all contaminant from the
material i.e. oil, grease, rust, moisture
prior to welding
Replace or dry the electrode
Reduce the arc length
Excessive penetraon – The weld
metal is below the surface level of
the material and hangs below
Heat input too high
Poor weld technique
Reduce the amperage or use a smaller
electrode and lower amperage
Use correct welding travel speed
Burning through – Holes within the
material where no weld exists
Heat input too high Use lower amperage or smaller
electrode
Use correct welding travel speed
Poor fusion – Failing of weld material
to fuse either with the material to be
welded or previous weld beads
Insucient heat level
Poor welding technique
Work piece dirty
Increase the amperage or increase the
electrode size and amperage
Joint design must allow for full access to
the root of the weld
Alter welding technique to ensure
penetraon such as weaving, arc
posioning or stringer bead technique
Remove all contaminant from the
material i.e. oil, grease, rust, moisture
prior to welding