Metal Inert Gas (MIG) welding is a critical skill for welding professionals in Kenya, widely applied in manufacturing, automotive repair, construction, and fabrication industries. This chapter focuses on the safe and effective execution of MIG welding operations, emphasizing occupational health and safety standards relevant to the Kenyan workplace. Understanding and implementing these standards not only protect the welder but also ensure regulatory compliance and maintain workplace productivity. Proper safety practices and hazard management are essential to mitigate risks inherent in welding environments.

1.1 Occupational health and safety standards

Occupational health and safety in MIG welding involves adherence to legal regulations, identification and management of hazards, and fostering a safe working environment. Kenyan welding workshops face risks such as exposure to hazardous fumes, electrical hazards, and ergonomic strain, necessitating comprehensive safety protocols. This topic explores the framework and practical measures that welders and supervisors must observe to safeguard health and safety.

1.1.1 Workplace legislation and standards

Legislation and standards set the minimum duties that a welding workshop must meet to protect people from harm. They cover matters such as safe systems of work, training, protective equipment, ventilation and inspection. Example: a workshop fabricating steel gates and window frames with MIG welding must be able to show that its welders are trained, protected and supervised in line with these rules.

Relevant Kenyan Legislation

Kenya's Occupational Safety and Health Act (OSHA) 2007 is the primary legislation governing workplace safety, including welding operations. It mandates employers to provide safe working conditions, proper training, and personal protective equipment (PPE). Compliance with OSHA ensures legal protection and reduces the incidence of workplace accidents.

International Welding Safety Standards

International standards such as those from the American Welding Society (AWS) and the International Organization for Standardization (ISO) complement Kenyan laws by providing detailed safety protocols specific to MIG welding. These include guidelines on ventilation, electrical safety, and PPE usage that Kenyan workshops often adopt to enhance safety.

Role of Regulatory Bodies

The Directorate of Occupational Safety and Health Services (DOSHS) enforces compliance with safety legislation through inspections and audits. Welding professionals must cooperate during inspections and implement recommended improvements to maintain certification and operational licences.

Licensing and Certification Requirements

Welding operators are expected to hold recognised qualifications from accredited TVET institutions and assessment bodies. These certifications normally require demonstration of safety knowledge and competence in MIG welding techniques, and employers use them as evidence that a welder can work without endangering others.

1.1.2 Workplace hazard identification

Identifying hazards is a proactive step that prevents accidents and health issues among welding personnel. A hazard is anything with the potential to cause harm, such as a trailing cable, an unsecured cylinder or a blocked extraction duct. Finding these before an injury occurs allows the workshop to correct them cheaply.

Methods for hazard identification

Regular workplace inspections, employee feedback, and use of hazard checklists help identify potential dangers. Example: during a weekly safety walk in a fabrication workshop, the supervisor may notice that the extraction arm is too far from the weld and that the welder is breathing the fume plume, and then reposition it.

A hazard walk-through checks the following:

• Gas cylinders: Confirm they are chained upright, capped when not in use and stored away from heat.
• Cables and hoses: Look for cuts, exposed conductors, loose connections and trip hazards.
• Combustible materials: Check for oily rags, paper, wood, paint and solvents near the welding area.
• Ventilation: Confirm extraction and general ventilation are working and not obstructed.
• Screens and signage: Check that welding screens protect passers-by and that warning signs are visible.

Use of hazard identification tools

Tools such as Job Safety Analysis (JSA) and hazard checklists assist in systematically identifying and documenting potential welding hazards. In a JSA the job is split into steps, such as positioning the plate, striking the arc and cleaning the weld, and the hazards of each step are listed with their controls. These tools guide corrective actions and training priorities.

Importance of worker involvement

Workers' input is vital as they have first-hand experience of operational risks. Encouraging welders to report near-misses and unsafe conditions improves hazard detection and mitigation.

1.1.3 Risk Assessment

Risk assessment evaluates the likelihood and severity of injury or harm from identified hazards, guiding control measures. It turns a list of hazards into priorities, so that the most dangerous ones, such as live cables in a damp bay, are controlled first.

Steps in conducting risk assessment

1. Identify hazards: Recognise all potential sources of harm related to MIG welding.
2. Determine who might be harmed: Consider welders, supervisors, and nearby workers.
3. Evaluate risks: Assess the probability and consequences of incidents occurring.
4. Decide on control measures: Implement engineering, administrative, or PPE controls.
5. Record findings: Maintain clear documentation for legal compliance.
6. Review and update: Regularly reassess risks to reflect changes in processes or environment.

Types of risk controls

Controls are applied in order of effectiveness: elimination (removing hazards), substitution (using safer materials), engineering controls (ventilation systems, screens), administrative controls (training, procedures), and PPE (helmets, gloves) as the last line of defence.

Risk matrix application

Using a risk matrix helps prioritise hazards by combining likelihood and impact ratings, enabling effective allocation of resources. Each factor is scored, for example from 1 (very low) to 5 (very high), and the scores are multiplied.

Formula: Risk rating = likelihood × severity

Substitution: Risk rating = 3 × 5

Working: 3 × 5 = 15

Result: Risk rating = 15

An electric shock hazard rated as possible (3) with a fatal outcome (5) scores 15, which is high and demands immediate controls.

Impact on insurance and compliance

Accurate risk assessments influence insurance premiums and demonstrate compliance during DOSHS audits, protecting the workshop's financial and legal standing.

Worker training based on risk findings

Training programmes tailored to identified risks improve worker awareness and reduce accident rates. Example: if the assessment shows that welders often work near damp floors, the workshop can run focused training on electrical safety and dry working conditions.

1.1.4 Workshop Incident/Accident reporting

Effective incident reporting systems are essential for learning from accidents and preventing recurrence. A report records what happened, who was involved and what must change. Example: a welder who nearly trips over a gas hose and reports it allows the supervisor to reroute the hose before anyone is hurt.

Purpose of incident reporting

Reporting incidents documents occurrences, facilitates investigations, and informs corrective actions to enhance workplace safety.

Types of reportable incidents

These include near misses, minor injuries, major accidents, equipment failures, and environmental spills related to welding operations.

Reporting procedures

1. Make the area safe: Switch off the machine, close the cylinder valve and remove any immediate danger.
2. Give first aid: Attend to injured persons and call for help where needed.
3. Report immediately: Tell the supervisor as soon as possible, in person or by the agreed channel.
4. Record the details: The supervisor completes the standard incident form with date, time, place, people involved and a description of events.
5. Preserve the scene: Leave equipment and materials as found, where safe, so that investigators can see the conditions.
6. Notify the authorities: The supervisor notifies DOSHS when required by law.
7. Follow up: File the report and track the corrective actions to completion.

Investigation and root cause analysis

Investigations identify underlying causes beyond immediate factors, such as inadequate training or faulty equipment, enabling targeted interventions.

Feedback and continuous improvement

Outcomes of investigations should be shared with all staff to promote awareness and prevent similar incidents, fostering a culture of continuous safety improvement.

1.1.5 Workplace ergonomics and work design

Proper ergonomics in welding reduces physical strain, preventing musculoskeletal disorders that are common among welders. Good work design fits the job to the welder, for example by bringing the workpiece to a comfortable height instead of making the welder stoop over it for an hour.

Principles of ergonomics in welding

Ergonomics involves designing workstations and tasks to fit the worker's physical capabilities, minimising awkward postures and forceful exertions.

Common ergonomic hazards

Prolonged bending, repetitive motions, and heavy lifting during MIG welding can cause back pain, carpal tunnel syndrome, and fatigue. Holding a heavy torch cable at arm's length and working with the neck bent under a helmet add to the strain.

Ergonomic workstation design

Adjustable work tables, appropriate seating, and positioning of welding equipment reduce strain. Example: a workshop may fit height-adjustable benches so that welders of different statures can work with the joint at elbow height, and hang the torch cable on a support so that its weight is not carried by the wrist.

Job rotation and break scheduling

Rotating welders between tasks and scheduling regular breaks reduce repetitive strain injuries and improve productivity.

Training on safe work practices

Teaching welders proper body mechanics and lifting techniques helps prevent injuries and enhances long-term career sustainability. Heavy plates should be lifted with a bent-knee posture, shared between two people or moved with a hoist or trolley.

1.1.6 Workshop waste management

Managing welding waste properly protects the environment and complies with Kenyan environmental regulations. A workshop produces offcuts, spent consumables and packaging every day, and each must go to the correct place. Example: steel offcuts go to the scrap bin for resale while used solvent rags go to a closed hazardous waste container.

Types of welding waste

Common wastes include metal scraps, wire off-cuts, spent contact tips and nozzles, empty shielding gas cylinders, grinding discs and packaging materials, some of which are hazardous.

Waste segregation practices

Separating recyclable metals from hazardous waste like spent solvents ensures proper disposal and recycling opportunities.

Disposal methods and compliance

Workshops must follow NEMA guidelines for disposal of hazardous waste and ensure waste handlers are licensed. Empty and part-used gas cylinders are returned to the supplier and not dumped.

Recycling and reuse initiatives

Recovering metal scraps for resale or reuse reduces environmental impact and can generate additional income for workshops. Different metals such as steel, aluminium and copper are kept in separate bins so that they keep their resale value.

Training workers on waste handling

Educating welders about safe waste handling minimises risks of contamination and injury.

1.1.7 Workplace environmental safety

Environmental safety extends beyond waste management to include pollution control and resource conservation in welding workshops. It protects the surroundings of the workshop, including neighbours, soil and water.

Air quality control

Proper ventilation systems are critical to remove welding fumes and gases from the workshop and to prevent them accumulating or drifting to neighbouring premises, protecting worker respiratory health.

Noise control measures

Enclosing noisy operations such as grinding in a separate bay, and scheduling noisy work away from quiet areas, reduce disturbance to neighbours and the risk of hearing loss.

Energy conservation

Implementing energy-efficient welding equipment and lighting reduces operational costs and environmental footprint. Switching machines off when not in use is a simple habit that saves electricity.

Spill prevention and control

Measures such as drip trays and spill kits prevent contamination of soil and water sources from oils and chemicals.

Compliance with environmental regulations

Adhering to National Environment Management Authority (NEMA) standards ensures legal operation and community goodwill.

1.1.8 Workshop safety

Workshop safety encompasses all practices that prevent injuries and maintain a secure working environment. It combines written rules, correct protective equipment and a workshop layout that keeps dangerous activities apart.

1.1.8.1 Regulations

Workshop safety regulations are the written rules that every person entering the welding area must follow. They turn legal duties into clear daily behaviour. Example: a notice at the entrance of a MIG bay stating that helmets and gloves must be worn before striking an arc.

Typical workshop rules include:

• Wear PPE at all times: No one welds, grinds or watches welding closely without the correct protection.
• Authorised use only: Only trained and authorised persons operate welding machines.
• No flammables near welding: Fuels, solvents, paper and oily rags are kept out of the welding area.
• Report defects: Damaged cables, torches or regulators are tagged and reported, not used.
• Keep walkways clear: Cables, hoses and materials must not block exits or routes.
• No horseplay or intoxication: Workers under the influence of alcohol or drugs must not enter the workshop.
• Know emergency arrangements: Everyone must know where extinguishers, first aid kits and exits are.

1.1.8.2 Personal Protective Equipment

Welders must use helmets with appropriate filters, gloves, aprons, and safety boots to shield against sparks, heat, and UV radiation. PPE is the last line of defence, so it must fit, be clean and be replaced when damaged.

1.1.8.3 Layout

A well-planned workshop layout separates dangerous activities and gives people safe routes and quick escape. Example: MIG welding bays can be placed along a ventilated wall with screens between them, while the cylinder store sits outside the main working area.

Good layout practice includes:

• Welding bays and screens: Each bay is enclosed by non-reflective, flame-resistant screens so that arc light does not reach others.
• Ventilation and lighting: Bays are placed where extraction is effective and with enough light for safe working and inspection.
• Separation of processes: Grinding, cutting and painting are kept apart from welding to limit sparks reaching paint and solvents.
• Cylinder storage: Cylinders are stored in a secured, shaded, well-ventilated area away from heat and electrical equipment.
• Clear routes and exits: Walkways are marked, exits are unobstructed, and extinguishers are located near exits and bays.
• Machine placement: Power sources are positioned on dry, firm ground with cables laid so that they are not driven over or tripped on.

1.1.9 Workplace procedures

Standard procedures guide safe and efficient MIG welding operations. They ensure that every welder follows the same safe sequence, whoever is on shift.

1.1.9.1 Roles and responsibilities

Safety works only when everyone knows what they are responsible for. Employers are responsible for risk assessments, safety training, and provision of PPE, while employees must adhere to safety procedures and report hazards. In welding workshops, this dual responsibility fosters a culture of safety and accountability.

Employer and supervisor duties:

• Provide a safe workplace: Maintain machines, ventilation and layout in safe condition.
• Train workers: Give induction and task-specific training before welders work unsupervised.
• Supply PPE: Issue suitable PPE free of charge and replace damaged items.
• Assess risk: Carry out and review risk assessments.
• Enforce the rules: Supervise work and correct unsafe behaviour promptly.

Welder duties:

• Follow procedures: Work according to training and workshop rules.
• Use PPE correctly: Wear and care for the equipment provided.
• Report hazards and incidents: Tell the supervisor of unsafe conditions, near misses and injuries.
• Protect others: Use screens and warn bystanders before striking an arc.
• Do not interfere: Never disable guards, extraction or safety devices.

1.1.9.2 Compliance

Compliance means following the law, the workshop rules and the safe working sequence every time, not only when inspected. Supervisors check compliance by observation, inspections and review of records. Example: a welder who skips the post-welding fire check may leave smouldering material that ignites after the workshop closes.

A compliant welding sequence is:

1. Check the area: Remove or cover flammables and, where the workshop uses hot work permits, obtain one.
2. Put on PPE: Wear helmet, gloves, protective clothing and boots, with clothing buttoned.
3. Confirm ventilation: Switch on extraction and position screens.
4. Weld safely: Keep a stable posture, keep cables dry and off the floor, and avoid contact with live parts.
5. Monitor conditions: Watch ventilation, sparks and bystanders throughout the work.
6. Shut down: Switch off the machine, close the cylinder valve and coil the cables and torch neatly.
7. Inspect and clean: Check the surroundings for smouldering material, inspect the welds and tidy the bay.

1.1.9.3 Documentation

Documentation provides proof that procedures were followed and supports quality control and traceability. Logging welding parameters, maintenance, and safety checks allows problems to be traced to their cause. Example: a maintenance log showing that a regulator was serviced explains when a leak could have started.

Records kept in a welding workshop include:

• Risk assessments and JSA sheets: Show hazards and the controls agreed.
• Hazard register: Lists identified hazards, who is responsible and when they were corrected.
• Training records: Show who has been trained and when refresher training is due.
• PPE issue register: Records what PPE each worker received and when it was replaced.
• Inspection and maintenance logs: Record checks on machines, cables, torches, regulators and ventilation.
• Incident and near-miss reports: Record events, investigations and corrective actions.
• Welding parameter records: Record settings and outcomes for quality control and traceability.

1.1.9.4 Communication

Clear communication makes sure that hazards identified on paper are understood on the floor. Proper communication of identified hazards through safety meetings and signage ensures all personnel are informed and vigilant. Example: a short talk at the start of the shift warns that a bay is being used for aluminium welding and needs extra ventilation.

Common communication methods are:

• Toolbox talks: Short briefings on a single topic, such as fume control or cylinder handling.
• Safety signs: Standard colours and symbols show prohibitions (red), warnings (yellow), mandatory actions (blue) and safe conditions (green).
• Notice boards: Display rules, emergency numbers, assembly points and recent incident lessons.
• Hand signals: Used when helmets and noise make speech difficult.
• Reporting lines: Workers know whom to inform about hazards and how to do it.

1.1.9.5 Emergency procedures

Emergency procedures set out what everyone must do when fire, injury or a gas leak occurs. Clear evacuation routes, first aid kits, and trained personnel ensure prompt response to accidents. Drills let workers practise so that they act correctly under stress.

A basic response is:

1. Raise the alarm: Shout a warning and activate the alarm so that everyone knows.
2. Isolate the hazard: If safe to do so, switch off the machine and close the cylinder valve.
3. Fight small fires only if safe: Use the correct extinguisher only if trained and the exit is behind you.
4. Evacuate: Leave by the marked route and go to the assembly point.
5. Account for everyone: The supervisor checks that all workers are out and informs the emergency services of anyone missing.
6. Treat burns and injuries: Cool burns under cool running water for at least 20 minutes and control bleeding with a clean dressing until help arrives.
7. Call for help and report: Contact emergency services and record the event afterwards.

1.1.10 Welding hazards

Understanding specific hazards in MIG welding enables targeted risk management. Welding exposes the operator to arc radiation, toxic fumes, electric shock, fire, noise and gas hazards, and each requires its own control measures. Arc radiation and electric shock are covered at the end of this section.

1.1.10.1 Fire/Burns

Sparks, spatter and hot metal can ignite flammable materials and burn skin. Burns also occur when a welder touches a freshly welded workpiece or hot nozzle. Example: spatter falling into an open bin of oily rags in the next bay can start a fire minutes after the welder has left.

Control measures include:

• Clear the area: Remove flammable materials from the welding zone and cover what cannot be moved with fire-resistant blankets.
• Fire watch: Have someone watch for sparks during, and for a period after, welding.
• Extinguishers ready: Keep suitable extinguishers within easy reach and serviced.
• Protective clothing: Wear flame-resistant clothing with no open pockets or turn-ups where sparks can collect.
• Mark hot work: Mark hot workpieces and use tongs or gloves to handle them.
• Treat burns promptly: Cool burns under cool running water for at least 20 minutes and seek medical care for serious burns.

1.1.10.2 Cuts

Cuts occur from sharp plate edges, burrs left after cutting, wire ends and grinding discs, particularly when handling thin sheet and cut plate. Example: a welder pulling an unprotected hand along a freshly sheared edge of a plate can suffer a deep laceration.

Control measures include:

• Wear gloves: Use suitable gloves when handling plate, sheet and offcuts.
• Deburr edges: Remove sharp edges and burrs before handling and fitting parts.
• Handle wire carefully: Hold the wire end when cutting it from the spool, since cut ends can spring out and injure eyes and hands.
• Guard grinders: Keep guards in place and use the correct disc, with safety glasses and face shield.
• Lift correctly: Use two people, clamps or lifting aids for large or heavy plate.
• Dress wounds: Clean and cover cuts at once, and report them.

1.1.10.3 Fumes

Welding fume is a mixture of fine metal oxide particles and gases produced when metal and wire vaporise in the arc. Breathing it can cause irritation, metal fume fever and long-term lung damage. MIG welding also uses shielding gases such as argon and carbon dioxide, which can cause breathing problems if inhaled excessively or if they displace oxygen in confined spaces.

Important points include:

• Galvanised steel: Zinc coatings give off fume that can cause metal fume fever, so the coating is removed from the weld area or extra ventilation is used.
• Coatings and solvents: Paint, oil and some degreasing solvents can break down in the arc into toxic gases, so surfaces must be clean and dry before welding.
• Aluminium welding: The arc can produce ozone, which irritates the lungs.
• Confined spaces: Shielding gas can displace air, so welding in tanks and similar spaces needs forced ventilation and monitoring.
• Controls: Use local exhaust ventilation close to the arc, keep the head out of the fume plume, and wear a respirator when extraction is not enough.

1.1.10.4 Noise

MIG arc welding itself is moderately noisy, but grinding, chipping, hammering and air tools in the same area produce much higher levels. Hearing damage builds up gradually and is permanent, so it is often ignored until it is too late. Example: a welder who grinds welds daily without earmuffs may notice ringing in the ears at the end of every shift.

Control measures include:

• Hearing protection: Wear earmuffs or earplugs when working in noisy areas, commonly above about 85 dB(A).
• Screens and barriers: Separate noisy operations from other work areas.
• Maintain tools: Well-maintained, properly guarded tools run quieter.
• Limit exposure: Rotate noisy tasks and take breaks away from noise.
• Vibration: Prolonged use of vibrating grinders can cause hand-arm vibration syndrome, so use low-vibration tools, keep a light grip and take breaks.

1.1.10.5 Gas explosion

Shielding gas cylinders hold gas at high pressure. A cylinder that falls and breaks its valve can be thrown across the workshop, and heat or a leak can cause fire or explosion where fuel gases or flammable vapours are present. Escaping argon or mixed gas can also displace oxygen and suffocate people in poorly ventilated areas.

Safe handling includes:

• Secure upright: Chain or strap cylinders upright, in storage and in use.
• Protect valves: Keep valve caps on when cylinders are stored or moved, and move them on a trolley.
• Store correctly: Keep cylinders cool, shaded and away from heat, sparks and electrical equipment.
• Check for leaks: Use soapy water on connections, never a flame, and tighten or replace faulty fittings.
• Close valves: Close the cylinder valve when work stops and at the end of the day.
• Use regulators properly: Use only regulators designed for the gas, and report any damage immediately.
• Ventilate: Keep storage and working areas ventilated to prevent gas accumulation.

Electric shock

Electric shock is a serious hazard because the welding circuit, the primary supply and the machine's internal parts can all carry dangerous current. Contact with live electrical components can lead to shocks or electrocution, especially in damp conditions or when the welder is sweating. Example: a worn torch cable lying in a puddle can give a welder a shock when they touch the workpiece.

Key practices include:

• Proper earthing: Machines and workpieces are earthed correctly according to the manufacturer's instructions.
• Insulation: Inspect cables, torch leads and connectors and replace any with damaged insulation.
• Residual current devices: Use RCDs on the supply to cut power quickly if current leaks to earth.
• Dry conditions: Keep the floor, gloves and clothing dry, and stand on insulating material where conditions are damp.
• Authorised repairs: Only qualified persons open machines or repair electrical faults, and the machine is isolated from the supply first.

Arc radiation and eye protection

The MIG arc emits intense visible light together with ultraviolet and infrared radiation. Ultraviolet and infrared radiation emitted during welding can cause eye injuries and skin burns without adequate protection. Arc eye feels like sand in the eyes some hours after exposure, and even a short unprotected glance can cause it.

Protective measures include:

• Use a filter lens: Always lower the helmet before striking the arc, and use a shade suited to the welding current.
• Cover skin: Wear long sleeves, gloves and a buttoned collar so that no skin is exposed to the arc.
• Use screens: Place screens around the bay so that bystanders and nearby welders are protected.
• Warn others: Call out before striking an arc so that people can look away.
• Replace damaged lenses: Cracked or scratched helmets and lenses must be replaced immediately.

1.1.11 Housekeeping

Good housekeeping maintains a safe, orderly, and efficient welding workshop. Most slips, trips and small fires in welding bays start with clutter, spatter and oily rags left lying around.

1.1.11.1 Cleaning

Cleaning is the daily routine that keeps floors, benches and machines free of hazards. Removing metal scraps, dust, and oil spills reduces slip, trip, and fire hazards. Example: sweeping spatter and wire offcuts from the bay floor at the end of every job prevents injuries to feet and knees.

Key cleaning practices are:

• Daily routines: Clean the bay, benches and floor at the end of each shift.
• Tool and equipment organisation: Storing tools properly prevents damage and facilitates quick access, enhancing productivity.
• Cable and hose care: Coil cables and hoses neatly after use so they are not trip hazards.
• Inspection and maintenance schedules: Routine checks and servicing of welding machines and ventilation systems prevent breakdowns and unsafe conditions.
• Worker responsibility and accountability: Assigning housekeeping duties and encouraging personal responsibility maintains high safety standards.

1.1.11.2 Waste management

In housekeeping, waste management is the daily collection and removal of waste before it becomes a hazard. Prompt removal of waste materials maintains cleanliness and environmental safety. The rules for sorting and final disposal are those set out in workshop waste management.

Practical routines include:

• Place bins at each bay: Provide labelled bins for offcuts, wire ends and used consumables.
• Empty regularly: Empty bins before they overflow and at the end of each shift.
• Separate oily rags: Keep them in a closed metal container away from the welding area.
• Keep waste away from sparks: Do not store combustible waste near welding bays.
• Return empty cylinders: Move empty cylinders to the designated store for collection.

Chapter Summary

This chapter covers the essential aspects of carrying out Metal Inert Gas (MIG) welding with a strong emphasis on occupational health and safety, including relevant workplace legislation, hazard identification, risk assessment, and proper incident reporting. It highlights the importance of ergonomics, environmental safety, workshop layout, personal protective equipment, and established procedures for compliance and emergency response in welding operations. The interpretation of technical drawings is addressed, focusing on dimensions, tolerances, and welding symbols critical for accurate fabrication. The chapter reviews MIG welding equipment and accessories, detailing their types and maintenance requirements to ensure operational efficiency. Preparation of welding materials involves precise measuring, marking, cutting, and edge preparation for various thicknesses. Key welding parameters such as current, wire feed speed, and torch angle are explained alongside different modes of metal transfer including short circuit and spray arc techniques. The selection and role of shielding gases like argon and helium are examined in relation to material types such as steel, aluminium, copper, and tungsten. Welding positions and joint types are described with their specific applications, while common weld defects are identified with guidance on their causes and prevention. Finally, finishing processes are discussed, covering methods like grinding, polishing, and painting to achieve quality welds, culminating in practical application of MIG welding on different metals and positions.