Arc Welders

About Arc Welders

Arc welders are fundamental power tools that use electrical current to create an arc between an electrode and metal workpiece, generating temperatures exceeding 3,600°C to fuse metals permanently together. Also known as stick welders or MMA (Manual Metal Arc) welders, these machines are prized for their versatility, portability, and ability to produce strong welds on mild steel, stainless steel, and cast iron in virtually any environment. Unlike gas-shielded welding processes, arc welders use flux-coated electrodes that protect the weld pool, making them ideal for outdoor site work, agricultural repairs, and general fabrication where wind conditions would disrupt other welding methods.

Modern inverter-based arc welders have revolutionised this traditional process, transforming heavy transformer machines into lightweight, compact units typically weighing between 5-15kg. These advanced welders operate efficiently from standard 240v UK power supplies, with models ranging from 100A units suitable for light DIY work through to professional 180A+ machines capable of welding materials up to 10mm thick. The inverter technology provides superior arc stability, reduced power consumption, and helpful features like hot start and anti-stick functions that make arc welding more accessible to beginners whilst maintaining the performance professionals demand.

The selection at Tooled-Up.com features quality arc welding equipment from trusted brands like Draper, offering both standard and turbo arc welder configurations. These machines cater to everyone from home workshop enthusiasts tackling garden furniture and vehicle restoration projects, through to professional fabricators, maintenance engineers, and construction site welders requiring reliable portable welding capabilities. With stepless current adjustment, thermal overload protection, and robust construction designed for UK conditions, these arc welders deliver dependable performance across diverse metalworking applications.

Jargon Buster

• Amperage (A): The welding current output measured in amps, typically ranging from 70A to 200A. Higher amperage enables welding of thicker materials—as a general rule, you require approximately 40A per millimetre of mild steel thickness. A 140A welder handles materials up to 6mm, whilst 180A models manage 10mm sections.
• Duty Cycle: The percentage of a 10-minute period that the welder can operate continuously at a specified amperage before requiring cooling time. A 60% duty cycle at 120A means the machine can weld for 6 minutes before needing a 4-minute rest. Professional applications benefit from higher duty cycles to maintain productivity.
• Inverter Technology: Modern electronic circuitry that converts 240v mains power through high-frequency switching, creating lighter and more efficient welders compared to traditional transformer designs. Inverter arc welders offer better arc control, portability, and consistent performance with reduced electricity consumption.
• Electrode: The consumable metal rod coated in flux that conducts electrical current and provides filler material for the weld. Common diameters include 1.6mm, 2.5mm, 3.2mm, and 4mm, with electrode selection depending on material thickness and welding position. The flux coating creates protective gas and slag during welding.
• Hot Start: A feature that delivers a brief surge of additional current when striking the arc, making it easier to initiate welding without the electrode sticking to the workpiece. Particularly valuable for beginners and when using larger diameter electrodes.
• Thermal Overload Protection: An essential safety feature that automatically shuts down the welder when internal temperatures exceed safe operating limits, preventing component damage from continuous use or inadequate cooling. The machine resets automatically once cooled sufficiently.

Who Uses Arc Welders?

• Fabricators and metalworkers constructing steelwork, gates, railings, architectural metalwork, and structural components
• Agricultural engineers and farmers performing on-site repairs to machinery, trailers, livestock equipment, and farm infrastructure
• Maintenance fitters in manufacturing plants, industrial facilities, and commercial premises
• Construction site operatives installing structural steelwork, reinforcement, and temporary works
• Automotive technicians and motorsport fabricators working on chassis repairs, exhaust systems, and roll cage construction
• Plant mechanics and heavy equipment operators maintaining earthmoving machinery, cranes, and industrial plant
• Marine engineers and dockyard workers repairing vessels, containers, and harbour installations
• Utility maintenance teams servicing infrastructure, pipework, and street furniture
• DIY enthusiasts and home workshop users tackling vehicle restoration, garden projects, trailer repairs, and general metalwork
• Engineering students and welding apprentices learning fundamental joining techniques
• Self-employed mobile welders providing on-site repair and fabrication services

How to Choose the Right Arc Welders

Amperage Capacity: Match the welder's output to your typical material thickness. For occasional DIY work and repairs up to 6mm mild steel, a 130-140A machine provides adequate capacity. Tradespeople regularly welding 8-10mm sections should consider 160-180A models. Remember that most UK domestic 13A sockets safely support welders up to approximately 140A—higher powered machines may require dedicated 16A or 32A circuits installed by a qualified electrician.

Duty Cycle Requirements: Professional users performing continuous fabrication work need machines with 60% or higher duty cycles at their commonly used amperage settings. Weekend DIY users can manage with lower duty cycles provided they allow adequate cooling intervals between welds. Turbo arc welders typically feature enhanced cooling systems that improve duty cycle performance whilst maintaining compact dimensions.

Portability and Construction: Modern inverter arc welders from Draper weigh significantly less than older transformer-based machines, typically between 5-15kg depending on capacity. If you require site mobility, transport equipment between locations frequently, or work at height, weight becomes a critical consideration. Look for robust carry handles, protective corner guards, and durable cases that withstand construction site conditions.

Power Supply and Plug Configuration: Verify your electrical supply matches the welder specifications. Most models operate from standard 240v single-phase supplies, though higher amperage units may require 16A industrial plugs rather than standard 13A domestic plugs. Consider whether you need to weld at locations with limited power availability—some sites may only offer reduced capacity supplies.

Control Features and Adjustability: Stepless current adjustment provides precise control for different electrode sizes and material thicknesses. Hot start functions deliver extra current to establish the arc without sticking, whilst anti-stick technology prevents electrodes from welding to the workpiece during arc initiation—both features significantly benefit less experienced welders. Digital displays offer accurate current readings, though simple analogue dials provide robust, intuitive control.

Thermal Protection and Reliability: Thermal overload protection prevents damage from excessive use by automatically shutting down the machine when internal temperatures exceed safe limits. Fan cooling extends operating periods between overload events. Consider brand reputation and warranty coverage—Tooled-Up stocks reliable Draper arc welders backed by manufacturer support and readily available service within the UK.

Popular Accessories

• Welding Electrodes: Stock various diameter rods (1.6mm to 4mm) suitable for your typical applications—6013 general purpose electrodes work well for mild steel, whilst 7018 low-hydrogen rods suit structural welding
• Earth Clamp: Heavy-duty return clamp that completes the electrical circuit—upgrade to larger capacity clamps for improved contact on thicker materials and better current flow
• Electrode Holder: Insulated handle assembly that grips the welding rod securely—spare holders or upgraded models improve comfort during extended welding sessions
• Auto-Darkening Welding Helmet: Essential eye protection with electronic filters (typically shade 9-13) that instantly darken when detecting arc light, providing superior comfort and safety compared to passive helmets
• Welding Gauntlets: Heat-resistant leather gloves protecting hands and forearms from sparks, molten metal spatter, and radiant heat
• Chipping Hammer and Wire Brush: Essential tools for removing flux slag and cleaning welds between passes to ensure quality multi-pass welds
• Welding Magnets: Positioning aids holding workpieces at precise 45°, 90°, and 135° angles during tack welding and assembly
• Heavy-Duty Welding Cables: Extensions for earth and electrode circuits when working away from the machine location
• Welding Screens and Curtains: Portable barriers protecting others from arc flash and UV radiation in shared workshops or site locations
• Electrode Storage Oven: Maintains low-hydrogen electrodes in dry conditions for critical structural welding applications

Safety Information

Personal Protective Equipment: Always wear appropriate PPE including a welding helmet complying with BS EN 379 (minimum shade 10 for arc welding), full leather welding gauntlets, flame-resistant cotton or leather clothing covering all exposed skin, and substantial safety boots. Never observe the welding arc without proper filtered eye protection—arc eye (welder's flash) causes extremely painful corneal burns requiring medical treatment. Even brief unprotected exposure damages eyesight.

Electrical Safety: Arc welders operate at high currents and must be correctly earthed. Ensure your electrical installation complies with BS 7671 wiring regulations and IET standards. Never weld in wet conditions, whilst standing on damp surfaces, or when wearing moisture-soaked clothing. Always disconnect the power supply before changing electrodes or performing any maintenance. Higher amperage welders requiring 16A or 32A dedicated circuits must be installed by a qualified electrician familiar with Part P building regulations.

Fume Extraction and Ventilation: Arc welding produces hazardous metal fumes and gases, particularly when working with flux-coated electrodes, galvanised materials, or painted surfaces. The HSE mandates adequate ventilation or Local Exhaust Ventilation (LEV) systems, especially in confined spaces or indoor workshops. Outdoor work benefits from natural ventilation, but indoor environments require mechanical extraction complying with COSHH (Control of Substances Hazardous to Health) regulations. Never weld in unventilated enclosed spaces.

Fire Prevention: Welding sparks and molten spatter travel up to 10 metres and can ignite flammable materials long after welding ceases. Remove combustible materials from the work area, keep an appropriate fire extinguisher (CO2 or dry powder rated for electrical fires) immediately accessible, and never weld near fuels, solvents, gas cylinders, or other hazardous substances. Be aware that sparks can smoulder in cracks, beneath materials, or inside hollow sections for hours before igniting.

Work Environment Organisation: Maintain adequate lighting, keep workspaces clear of trip hazards, and use non-flammable screening to protect bystanders from arc flash and UV radiation. Post warning signs when welding in shared workshops or construction sites. Ensure assistants and nearby workers wear appropriate eye protection even when not directly welding. Consider noise levels—arc welding in enclosed spaces may require hearing protection.

Frequently Asked Questions

What thickness of metal can I weld with a 140A arc welder?
A 140A arc welder effectively handles mild steel up to approximately 6mm thickness in a single pass, covering most DIY requirements including garden furniture, trailer repairs, vehicle bodywork, and light fabrication projects. For thicker sections, you can build up the joint using multiple weld passes, though this requires greater skill. Material type affects penetration—stainless steel and cast iron behave differently than mild steel and may require different electrode types and amperage settings.

Can I run an arc welder from a normal household socket?
Arc welders up to approximately 140A typically operate from standard UK 13A sockets on 240v domestic circuits, though you should verify the specific machine's current draw in the manufacturer's specifications. Ensure the circuit isn't shared with other high-power appliances like electric showers or cookers. More powerful welders (160A and above) often require dedicated 16A or 32A circuits with industrial-style plugs, necessitating installation by a qualified electrician. Always check your property's consumer unit capacity and circuit protection before purchasing.

What's the difference between standard and turbo arc welders?
Turbo arc welders incorporate enhanced cooling systems—typically more powerful fans and improved airflow design—that increase the duty cycle compared to standard models of similar amperage. This allows longer continuous welding periods before thermal overload protection activates, making turbo models more suitable for professional users performing sustained fabrication work. The improved cooling often comes with slightly increased weight and dimensions, though modern inverter designs keep this minimal.

Why does my electrode keep sticking to the workpiece?
Electrode sticking typically results from insufficient amperage for the rod diameter, excessively short arc length, or too-slow travel speed. Increase the current setting slightly, maintain a consistent 2-3mm arc gap, and ensure steady forward movement. Verify your earth clamp has good contact with clean, unpainted metal—poor earthing causes arc instability. Models with hot start and anti-stick functions significantly reduce this common beginner problem by automatically adjusting current during arc initiation and sticking events.

Do I need welding qualifications to use an arc welder for DIY projects?
No certification is required for personal DIY use in your own workshop or property. However, professional welders working on structural steelwork, pressure vessels, pipework, or safety-critical applications must hold relevant qualifications such as CSWIP certification, City & Guilds diplomas, or coded welder approval to specific British Standards (BS 4872) or European standards (EN ISO 9606). Employers must ensure welders are adequately trained and competent under CDM regulations and HSE guidance. Even for home use, attending a basic welding course significantly improves results, safety awareness, and confidence.