UNIMIG VIPER ARC 140 DC Inverter Welder Instruction Manual

UNIMIG VIPER ARC 140 DC Inverter Welder

Specifications

• Model : U31006
• Operating Manual : VIPER ARC 140

Product Features

• 10A Plug: Can be used on any domestic outlet, suitable for DIY home handyman or professional welder.
• LED Amperage Display : Bright LED display for precise amperage setting.
• I GBT Inverter Technology: Provides better performance, efficiency, and reliability.
• DC Lift Arc TIG : Allows easy ignition of the arc in DC TIG by touching and lifting the tungsten electrode.

Safety
Welding and cutting equipment can be dangerous if not operated correctly. It is important to follow all relevant safety regulations and read the instruction manual before installation and operation.

• Electric shock : Can be fatal. Take necessary precautions to avoid contact with live parts.
• Fumes and gases : Dangerous to inhale. Ensure proper ventilation or use an air-supplied respirator when welding or cutting certain materials.
• Arc rays : Harmful to eyes and skin. Wear appropriate protective gear.
• Fire hazard : Welding sparks and heat can cause fires. Avoid welding on flammable surfaces and be cautious of gas build-up.
• Electronic magnetic fields : May interfere with sensitive equipment. Keep a safe distance during welding, cutting, or heating operations.
• Noise : Excessive noise can damage hearing. Use ear protection in loud environments.
• Hot parts : Use welding gloves and protective clothing to handle hot parts and prevent burns.

Package Contents
The package includes the VIPER ARC 140 welding machine and its accessories. Refer to the product manual for a detailed list of included items.

Machine Layout

• Front Panel Layout
  Describe the layout and features of the front panel of the machine.

• Rear Panel Layout
  Describe the layout and features of the rear panel of the machine.

• Control Panel Layout
  Describe the layout and functions of the control panel of the machine.

• MMA: Machine Setup
  Provide step-by-step instructions on setting up the machine for MMA (STICK) welding.

• MMA: Welding Guide
  Provide a comprehensive guide on MMA (STICK) welding techniques and best practices.

• MMA (STICK) Troubleshooting
  Provide troubleshooting tips and solutions for common issues encountered during MMA (STICK) welding.

• TIG: Machine Setup
  Provide step-by-step instructions on setting up the machine for TIG welding.

• Recommended TIG Accessories
  List and describe the recommended accessories for TIG welding with the VIPER ARC 140.

• TIG Welding Guide
  Provide a comprehensive guide on TIG welding techniques and best practices.

• TIG Troubleshooting
  Provide troubleshooting tips and solutions for common issues encountered during TIG welding with the VIPER ARC 140.

FAQ

1. Q: Can I use the VIPER ARC 140 with any power outlet?
   A: Yes, the machine comes with a 10A plug that can be used on any domestic outlet.

2. Q: How do I check for gas leakage in TIG welding?
   A: Follow the recommended procedure provided in the operating manual, which includes connecting the regulator and gas hose assembly, slowly opening the cylinder valve, and observing the needle indicator on the contents pressure gauge.

3. Q: Who is authorized to repair the welding/cutting equipment?
   A: Only qualified technicians are authorized to undertake the repair of this equipment. Please refer to the safety notes and precautions in the manual.

Safety

• Welding and cutting equipment can be dangerous to both the operator and people in or near the surrounding working area if the equipment is not correctly operated. Equipment must only be used under the strict and comprehensive observance of all relevant safety regulations.

• Read and understand this instruction manual carefully before the installation and operation of this equipment.

• Machine operating safety

  • Do not switch the function modes while the machine is operating. Switching of the function modes during welding can damage the machine. Damage caused in this manner will not be covered under warranty.
  • Disconnect the electrode-holder cable from the machine before switching on the machine, to avoid arcing should the electrode be in contact with the workpiece.
  • Operators should be trained and or qualified.

• Electric shock: it can kill

  • Touching live electrical parts can cause fatal shocks or severe burns. The electrode and work circuit is electrically live whenever the output is on. The input power circuit and internal machine circuits are also live when power is on. In MIG/MAG welding, the wire, drive rollers, wire feed housing, and all metal parts touching the welding wire are electrically live. Incorrectly installed or improperly grounded equipment is dangerous.
  • Connect the primary input cable, according to Australian and New Zealand standards and regulations.
  • Avoid all contact with live electrical parts of the welding/cutting circuit, electrodes and wires with bare hands.
  • The operator must wear dry welding gloves while he/she performs the welding/cutting task.
  • The operator should keep the workpiece insulated from himself/herself.
  • Keep cords dry, free of oil and grease, and protected from hot metal and sparks.
  • Frequently inspect input power cable for wear and tear, replace the cable immediately if damaged, bare wiring is dangerous and can kill.
  • Do not use damaged, undersized, or badly joined cables.
  • Do not drape cables over your body.
  • We recommend (RCD) safety switch is used with this equipment to detect any leakage of current to earth.

• Fumes and gases are dangerous

  • Smoke and gas generated while welding or cutting can be harmful to people’s health. Welding produces fumes and gases. Breathing these fumes and gases can be hazardous to your health.
  • Do not breathe the smoke and gas generated while welding or cutting, keep your head out of the fumes.
  • Keep the working area well ventilated, use fume extraction or ventilation to remove welding/cutting fumes and gases.
  • In confined or heavy fume environments always wear an approved air-supplied respirator.
  • Welding/cutting fumes and gases can displace air and lower the oxygen level, causing injury or death. Be sure the breathing air is safe.
  • Do not weld/cut in locations near degreasing, cleaning, or spraying operations. The heat and rays of the arc can react with vapours to form highly toxic and irritating gases.
  • Materials such as galvanised, lead, or cadmium plated steel, containing elements that can give off toxic fumes when welded/cut. Do not weld/cut these materials unless the area is very well ventilated, and or wearing an air-supplied respirator.

• Arc rays: harmful to people’s eyes and skin

  • Arc rays from the welding/cutting process produce intense visible and invisible ultraviolet and infrared rays that can burn eyes and skin.
  • Always wear a welding helmet with the correct shade of filter lens and suitable protective clothing, including welding gloves while the welding/cutting operation is performed.
  • Measures should be taken to protect people in or near the surrounding working area. Use protective screens or barriers to protect others from flash, glare and sparks; warn others not to watch the arc.

• Fire hazard

  • Welding/cutting on closed containers, such as tanks, drums, or pipes, can cause them to explode. Flying sparks from the welding/cutting arc, hot workpiece, and hot equipment can cause fires and burns. Accidental contact of the electrode
    to metal objects can cause sparks, explosion, overheating, or fire. Check and be sure the area is safe before doing any welding/cutting.

  • The welding/cutting sparks & spatter may cause fire, therefore remove any flammable materials well away from the working area. Cover flammable materials and containers with approved covers if unable to be moved from the welding/cutting area.

  • Do not weld/cut on closed containers such as tanks, drums, or pipes, unless they are correctly prepared according to the required Safety Standards to ensure that flammable or toxic vapours and substances are totally removed, these can cause an explosion even though the vessel has been “cleaned”. Vent hollow castings or containers before heating, cutting or welding. They may explode.

  • Do not weld/cut where the atmosphere may contain flammable dust, gas, or liquid vapours (such as petrol)

  • Have a fire extinguisher nearby and know how to use it. Be alert that welding/cutting sparks and hot materials from welding/cutting can easily go through small cracks and openings to adjacent areas. Be aware that welding/cutting on a ceiling, floor, bulkhead, or partition can cause a fire on the hidden side.

• Gas cylinders

  •  Shielding gas cylinders contain gas under high pressure. If damaged, a cylinder can explode. Because gas cylinders usually are part of the welding/cutting process, be sure to treat them carefully. CYLINDERS can explode if damaged.
  • Protect gas cylinders from excessive heat, mechanical shocks, physical damage, slag, open flames, sparks, and arcs.
  • Ensure cylinders are held secure and upright to prevent tipping or falling over.
  • Never allow the welding/cutting electrode or earth clamp to touch the gas cylinder, do not drape welding cables over the cylinder.
  • Never weld/cut on a pressurised gas cylinder, it will explode and kill you.
  • Open the cylinder valve slowly and turn your face away from the cylinder outlet valve and gas regulator.

• Gas build-up

  • The build-up of gas can cause a toxic environment, deplete the oxygen content in the air resulting in death or injury. Many gases use in welding/cutting are invisible and odourless.
  • Shut off shielding gas supply when not in use.
  • Always ventilate confined spaces or use approved air-supplied respirator.

• Electronic magnetic fields

  • MAGNETIC FIELDS can affect Implanted Medical Devices.
  • Wearers of Pacemakers and other Implanted Medical Devices should keep away.
  • Implanted Medical Device wearers should consult their doctor and the device manufacturer before going near any electric welding, cutting or heating operation.

• Noise can damage hearing

  • Noise from some processes or equipment can damage hearing.
  • Wear approved ear protection if noise level is high.

• Hot parts

  • Items being welded/cut generate and hold high heat and can cause severe burns.
  • Do not touch hot parts with bare hands. Allow a cooling period before working on the welding/cutting gun. Use insulated welding gloves and clothing to handle hot parts and prevent burns.

Caution
Working environment

• The environment in which this welding/cutting equipment is installed must be free of grinding dust, corrosive chemicals, flammable gas or materials etc., and at no more than a maximum of 80% humidity.
• When using the machine outdoors, protect the machine from direct sunlight, rainwater and snow, etc.; the temperature of the working environment should be maintained within -10°C to +40°C.
• Keep this equipment 30cm distant from the wall.
• Ensure the working environment is well ventilated.

Safety tips

• Ventilation: This equipment is small-sized, compact in structure, and of excellent performance in amperage output. The fan is used to dissipate heat generated by this equipment during the welding/cutting operation. Important: Maintain good ventilation of the louvres of this equipment. The minimum distance between this equipment and any other objects in or near the working area should be 30 cm. Good ventilation is of critical importance for the normal performance and service life of this equipment.
• Thermal Overload Protection: Should the machine be used to an excessive level, or in a high-temperature environment, poorly ventilated area or if the fan malfunctions the Thermal Overload Switch will be activated, and the machine will cease to operate. Under this circumstance, leave the machine switched on to keep the built-in fan working to bring down the temperature inside the equipment. The machine will be ready for use again when the internal temperature reaches a safe level.
• Over-Voltage Supply: Regarding the power supply voltage range of the machine, please refer to the “Main parameter” table. This equipment is of automatic voltage compensation, which enables the  maintaining of the voltage range within the given range. In case that the voltage of input power supply amperage exceeds the stipulated value, it is possible to cause damage to the components of this equipment. Please ensure your primary power supply is correct.
• Do not come into contact with the output terminals while the machine is in operation. An electric shock may occur.

Maintenance

• Exposure to extremely dusty, damp, or corrosive air is damaging to the welding/cutting machine. To prevent any possible failure or fault of this welding/cutting equipment, clean the dust at regular intervals with clean and dry compressed air of required pressure.
• Note: lack of maintenance can result in the cancellation of the guarantee; the guarantee of this welding/cutting equipment will be void if the machine has been modified, attempt to take apart the machine or open the factory-made sealing of the machine without the consent of an authorized representative of the manufacturer.

Troubleshooting

• Caution: Only qualified technicians are authorized to undertake the repair of this welding/cutting equipment. For your safety and to avoid Electrical Shock, please observe all safety notes and precautions detailed in this manual.

Attention! – Check For Gas Leakage (TIG ONLY)
At initial set up and at regular intervals we recommend to check for gas leakage
Recommended procedure is as follows:

1. Connect the regulator and gas hose assembly and tighten all connectors and clamps.
2. Slowly open the cylinder valve.
3. Set the flow rate on the regulator to approximately 8-10 L/min.
4. Close the cylinder valve and pay attention to the needle indicator of the contents pressure gauge on the regulator, if the needle drops away towards zero there is a gas leak. Sometimes a gas leak can be  slow and to identify it will require leaving the gas pressure in the regulator and line for an extended time period. In this situation it is recommended to open the cylinder valve, set the flow rate to 8 10 L/min, close the cylinder valve and check after a minimum of 15 minutes.
5. If there is a gas loss then check all connectors and clamps for leakage by brushing or spraying with soapy water, bubbles will appear at the leakage point.
6. Tighten clamps or fittings to eliminate gas leakage.

• IMPORTANT! – We strongly recommend that you check for gas leakage prior to operation of your machine. We recommend that you close the cylinder valve when the machine is not in use.
• Welding Guns Of Australia PTY LTD, authorised representatives or agents of Welding Guns Of Australia PTY LTD will not be liable or responsible for the loss of any gas.

 Machine Features

• 10A Plug
  • Plug in and play. The 10A power plug can be used on any domestic outlet, so it’s perfect for the DIY home handyman or the professional welder looking to take it anywhere.
• LED Amperage Display
  • Precise to the amp, the bright LED display makes it easier to dial in your desired amperage setting.
• IGBT Inverter Technology
  • Not every inverter is made equal. With UNIMIG’s ever-evolving, state-of-the-art IGBT Inverter technology, you get better performance, better efficiency, and better reliability.
• DC Lift Arc TIG
  • Lift Arc ignition allows the arc to be started easily in DC TIG by simply touching the tungsten to the workpiece and lifting it up to start the arc. This stops the tungsten tip sticking to the workpiece and breaking the tip from the tungsten electrode.
• Lightweight & Portable
  • Weighing just 4kg, the VIPER ARC 140 is ready to go anywhere you need it.
• Generator Ready
  • Minimum 8 kVA recommended.

Machine Specifications

Technical Data

TIG Specifications

• 15% @ 140A
• 60% @ 70A
• 100% @ 54A

TIG Welding Thickness Range| 1-5mm

STICK Specifications

• 15% @ 140A
• 60% @ 70A
• 100% @ 54A

STICK Welding Thickness Range| 2-8mm

Size & Weight

 Package Contents

 Machine Layout

1. Front Panel Layout
2. Control Panel
3. “+” Output Terminal
4. “-” Output Terminal
5. Rear Panel Layout
6.  On/Off Switch
7. Input Power Cord
8. Cooling Fan

 Control Panel Layout

1. Amperage Control Knob
2. Mode Selection Button
3. Welding Mode LED Indicators
4. Amperage LED Display
5. Power LED Indicator
6. Over Temp Warning LED Indicator

7. MMA: Machine Setup

1. For DCEP electrodes, connect the earth clamp to the  (-) dinse connection, and the electrode holder to the (+) dinse connection.
2. For DCEN electrodes, connect the earth clamp to the  (+) dinse connection, and the electrode holder to the (-) dinse connection.
3.  Connect the plug into a power point, then switch the  machine ON.
4. Ensure MMA (STICK) Mode is activated. You can  change welding process mode by pressing the Mode Selection Button. Adjust the amperage to your desired amount using the Amperage Control Knob.
5. Twist electrode holder to loosen grip.
6. Place electrode into electrode holder.
7. Twist electrode holder to tighten and securely grip  electrode.
8. Connect earth clamp to your workpiece.
9. Strike electrode to the workpiece to initiate arc.
10. Drag along workpiece to weld. Pull the electrode away from the workpiece to finish weld.

MMA: Welding Guide

One of the most common types of arc welding is Manual Metal Arc welding, also known as MMA welding. An electric current is used to strike an arc between the base material and a consumable electrode rod or ‘stick’. The electrode rod is made of a material that is compatible with the base material being welded. They are covered with a flux that gives off gaseous vapours that serve as a shielding gas and provide a layer of slag, both of which protect the weld area from atmospheric contamination. The electrode core itself acts as filler material. The residue from the flux that forms a slag covering over the weld metal must be chipped away after welding.

• The arc is initiated by momentarily touching the electrode to the base metal.
• The heat of the arc melts the surface of the base metal to form a molten pool at the end of the electrode.
• The melted electrode metal is transferred across the arc into the molten pool and becomes the deposited weld metal.
• The deposit is covered and protected by a slag which comes from the electrode coating.
• The arc and the immediate area are enveloped by an atmosphere of protective gas.

Manual Metal Arc (stick) electrodes have a solid metal wire core and a flux coating. These electrodes are identified by the wire diameter and by a series of letters and numbers. The letters and numbers identify the metal alloy and the intended use of the electrode.
The metal wire core works as a conductor of the current that maintains the arc. The core wire melts and is deposited into the welding pool.
The covering on a shielded metal arc welding electrode is called flux. The flux on the electrode performs many different functions.
These include:

• Producing a protective gas around the weld area.
• Providing fluxing elements and deoxidisers.
• Creating a protective slag coating over the weld as it cools.
• Establishing arc characteristics.
• Adding alloying elements.

Covered electrodes serve many purposes in addition to adding filler metal to the molten pool. These additional functions are provided mainly by the covering on the electrode.

Electrode Selection
As a general rule, the selection of an electrode is straight forward, in that it is only a matter of selecting an electrode of similar composition to the parent metal. However, for some metals, there is a choice of several electrodes, each of which has particular properties to suit specific classes of work.

• The size of the electrode generally depends on the thickness of the section being welded, and the thicker the section, the larger the electrode required. The table gives the maximum size of electrodes that may be used for various thicknesses of section based on using a general-purpose type 6013 electrode.

Average Thickness of Material| Maximum Recommended Electrode Diameter
---|---
1.0 – 2.0mm| 2.5mm
2.0 – 5.0mm| 3.2mm

5.0mm| 4.0mm

• Correct current selection for a particular job is an important factor in arc welding. With the current set too low, it is difficult to strike and maintain a stable arc. The penetration is reduced and beads with a distinct rounded profile will be deposited. Too high a current is accompanied by overheating of the electrode, resulting in undercut, burning through of the base metal and producing excessive spatter.

• Arc Length
  • To strike the arc, the electrode should be gently scraped on the work until the arc is established. There is a simple rule for the proper arc length; it should be the shortest arc that gives a good surface to the weld. An arc too long reduces penetration, produces spatter and gives a rough surface finish to the weld. An excessively short arc will cause sticking of the electrode and result in poor quality welds. The general rule of thumb for down hand welding is to have an arc length no greater than the diameter of the core wire.
• Electrode Angle
  • The angle that the electrode makes with the work is important to ensure a smooth, even transfer of metal. When welding in down hand, fillet, horizontal or overhead, the angle of the electrode is generally between 5 and 15 degrees towards the direction of travel. When vertical up welding, the angle of the electrode should be between 80 and 90 degrees to the workpiece.
• Travel Speed
  • The electrode should be moved along in the direction of the joint being welded at a speed that will give the size of run required. At the same time, the electrode is fed downwards to keep the correct arc length at all times. Excessive travel speeds lead to poor fusion, lack of penetration, etc., while too slow a rate of travel will frequently lead to arc instability, slag inclusions and poor mechanical  properties.
• Material and Joint Preparation
  • The material to be welded should be clean and free of any moisture, paint, oil, grease, mill scale, rust or any other material that will hinder the arc and contaminate the weld material. Joint preparation will depend on the method used include sawing, punching, shearing, machining, flame cutting and others. In all cases, edges should be clean and free of any contaminates. The chosen application will determine the type of joint.

MMA (STICK) Troubleshooting

1. No arc

   • Incomplete welding circuit: Check earth lead is connected. Check all cable connections.
   • Wrong mode selected : Check the MMA selector switch is selected.
   • No power supply: Check that the machine is switched on and has a power supply.

2. Porosity – Small cavities or holes resulting from gas pockets in weld metal

   • Arc length too long: Shorten the arc length.
   • Workpiece dirty, contaminated or moisture: Remove moisture and materials like paint, grease, oil, and dirt, including mill scale, from base metal.
   • Damp electrodes: Use only dry electrodes.

3. Excessive spatter

   • Amperage too high: Decrease the amperage or choose a smaller electrode.
   • Arc length too lon g: Shorten the arc length.

4. Weld sits on top, lack of fusion

   • Insufficient heat in put: Increase the amperage or choose a smaller electrode.
   • Workpiece dirty, contaminated or moisture: Remove moisture and materials like paint, grease, oil, and dirt, including mill scale, from base metal.
   • Poor welding technique: Use the correct welding technique or seek assistance for the correct technique.

5. Lack of penetration

   • Insufficient heat input: I ncrease the amperage or choose a smaller electrode.
   • Poor welding technique : Use the correct welding technique or seek assistance for the correct technique.
   • Poor joint preparation: Check the joint design and fit up, make sure the material is not too thick. Seek assistance for the correct joint design and fit up.

6. Excessive penetration – Burn through

   • Excessive heat input: Reduce the amperage or use a larger electrode.
   • Incorrect travel speed : Try increasing the weld travel speed.

7. Uneven weld appearance

   • Unsteady hand, wavering hand: Use two hands where possible to steady up, practise your technique.

8. Distortion – Movement of base metal during welding

   • Excessive heat input: Reduce the amperage or use a larger electrode.

   • Poor welding technique: Use the correct welding technique or seek assistance for the correct technique.

   • Poor joint preparation a nd/or joint design : Check the joint design and fit up, make sure the material is not too thick. Seek assistance for the correct joint design and fit up.

9. Electrode welds with different or unusual arc characteristic

   • Incorrect polarity: Change the polarity, check the electrode manufacturer for correct polarity.

 TIG: Machine Setup (TIG TORCH NOT INCLUDED)

1. For DCEN (-) start by connecting the TIG Torch  connector into the positive (+) dinse port. Align the notch, press it in, then twist to lock the torch in place.

2. Connect the earth clamp connector into the negative  (-) dinse port. Align the notch, press it in, then twist to lock the torch in place.
   NOTE : FOR TIG WELDING WE RECOMMEND USING AN ARGON FLOWMETER (NOT INCLUDED)

3. Place agon flowmeter regulator into your gas outlet.

4. Tighten securely with wrench.

5. Connect gas hose from the valve TIG torch to the  flowmeter outlet using the twist nut to tighten the fitting securely.

6. Turn gas bottle on and twist the knob to adjust gas flow  to 8-12L/min.

7. Connect the plug into a power point, then switch the  machine ON.

8. Ensure TIG Mode is activated. You can change welding process mode by pressing the Mode Selection Button. Adjust the amperage to your desired amount using the Amperage Control Knob.

9. Connect earth clamp to your workpiece.

10. Turn on the gas valve located on the TIG torch  handle.

11.  Lay the outside edge of the gas cup on the work  piece with the tungsten electrode 1-2mm from the workpiece.

12. With a small movement rotate the gas cup forward  so that the tungsten electrode touches the workpiece.

13.  After your desired pre-gas amount has run, rotate the gas cup in the reverse direction to lift the tungsten electrode from the workpiece to create the arc.

• IMPORTANT! – We strongly recommend that you check for gas leakage prior to operation of your machine. We recommend that you close the cylinder valve when the machine is not in use.
• Welding Guns Of Australia PTY LTD, authorised representatives or agents of Welding Guns Of Australia PTY LTD will not be liable or responsible for the loss of any gas.

Recommended TIG Accessories

 TIG Welding Guide

DC TIG Welding

• The DC power source uses what is known as DC (direct current), in which the main electrical component known as electrons flow in only one direction from the negative pole (terminal) to the positive pole (terminal). In the DC electrical circuit, there is an electrical principle at work which should always be taken into account when using any DC circuit. With a DC circuit, 70% of the energy (heat) is always on the positive side. This needs to be understood because it determines what terminal the TIG torch will be connected to (this rule applies to all the other forms of DC welding as well).
• DC TIG welding is a process in which an arc is struck between a tungsten electrode and the metal workpiece. The weld area is shielded by an inert gas flow to prevent contamination of the tungsten, molten pool and weld area. When the TIG arc is struck, the inert gas is ionized and superheated, changing its molecular structure, which converts it into a plasma stream. This plasma stream flowing between the tungsten and the workpiece is the TIG arc and can be as hot as 19,000°C. It is a very pure and concentrated arc which provides the controlled melting of most metals into a weld pool. TIG welding offers the user the highest amount of flexibility to weld the widest range of material thickness and types. DC TIG welding is also the cleanest weld with no sparks or spatter.
• The intensity of the arc is proportional to the current that flows from the tungsten. The welder regulates the welding current to adjust the power of the arc. Typically thin material requires a less powerful arc with less heat to melt the material, so less current (amps) is required. Thicker material requires a more powerful arc with more heat, so more current (amps) is necessary to melt the material.

Lift Arc Ignition for TIG Welding

• Lift Arc is a form of arc ignition where the tungsten electrode is touched to the workpiece and then pulled upwards to initiate an arc. When the machine detects that the tungsten has left the surface and a spark is present, it immediately (within microseconds) increases power, converting the spark to a full arc. It is a simple, safe, lower-cost alternative arc ignition process to HF (high frequency) and a superior arc start process to scratch start.
• Lift Arc ignition allows the arc to be started easily in DC TIG by simply touching the tungsten to the workpiece and lifting it to start the arc. This prevents the tungsten tip from sticking to the workpiece and breaking the tip from the tungsten electrode. There is a particular technique called “rocking the cup” used in the Lift Arc process that provides easy use of the Lift Arc function.
• TIG Welding Fusion Technique
  • Manual TIG welding is often considered the most difficult of all the welding processes. Because the welder must maintain a short arc length, great care and skill are required to prevent contact between the electrode and the workpiece. Similar to Oxygen Acetylene torch welding, TIG welding typically requires two hands
    and in most instances requires the welder to manually feed a filler wire into the weld pool with one hand while manipulating the welding torch in the other. However, some welds combining thin materials can be accomplished without filler metal, such as edge, corner, and butt joints. This is known as Fusion welding where the edges of the metal pieces are melted together using only the heat and arc force generated by the TIG arc. Once the arc is started, the torch tungsten is held in place until a weld pool is created, a circular movement of the tungsten will assist in creating a weld pool of the desired size. Once the weld pool is established, tilt the torch at about a 75° angle and move smoothly and evenly along the joint while fusing the materials together.

TIG Welding with Filler Wire Technique

• It is necessary for many situations with TIG welding to add a filler wire into the weld pool to build up weld reinforcement and create a strong weld. Once the arc is started, the torch tungsten is held in place until a weld pool is created, a circular movement of the tungsten will assist in creating a weld pool of the desired size. Once the weld pool is established, tilt the torch at about a 75° angle and move smoothly and evenly along the joint. The filler metal is introduced to the leading edge of the weld pool. The filler wire is usually held at about a 15° angle and fed into the leading edge of the molten pool.
• The arc will melt the filler wire into the weld pool as the torch is moved forward. Also, a dabbing technique can be used to control the amount of filler wire added. The wire is fed into the molten pool and retracted in a repeating sequence as the torch is moved slowly and evenly forward. It is essential during the welding to keep the molten end of the filler wire inside the gas shield as this protects the end of the wire from being oxidized and contaminating the weld pool.

Tungsten Preparation

• Always use DIAMOND wheels when grinding and cutting, and be weary of breathing the dust created by the tungsten. While tungsten is a tough material, the surface of a diamond wheel is harder, and this makes for smooth grinding. Grinding without diamond wheels, such as aluminium oxide wheels, can lead to jagged edges, imperfections, or poor surface finishes not visible to the eye that will contribute to weld inconsistency and weld defects.
• Always ensure to grind the tungsten in a longitudinal direction on the grinding wheel. Tungsten electrodes are manufactured with the molecular structure of the grain running lengthwise and thus grinding crosswise is “grinding against the grain.” If electrodes are ground crosswise, the electrons have to jump across the grinding marks, and the arc can start before the tip and wander. Grinding longitudinally with the grain causes the electrons to flow steadily and easily to the end of the tungsten tip. The arc starts straight and remains narrow, concentrated, and stable.
• 
• Electrode Tip/Flat
  The shape of the tungsten electrode tip is an important process variable in precision arc welding. A good selection of tip/flat size will balance the need for several advantages. The bigger the flat, the more likely arc wander will occur and the more difficult it will be to arc start. However, increasing the flat to the maximum level that still allows arc starts and eliminates arc wander will improve the weld penetration and increase the electrode life. Some welders still grind electrodes to a sharp point, which makes arc starting easier. However, they risk decreased welding performance from melting at the tip and the possibility of the point falling off into the weld pool.

Electrode Included Angle/Taper – DC
Tungsten electrodes for DC welding should be ground longitudinally and concentrically with diamond wheels to a specific included angle in conjunction with the tip/flat preparation. Different angles produce different arc shapes and offer different weld penetration capabilities. In general, blunter electrodes that have a larger included angle provide the following benefits:

• Last longer
• Have better weld penetration
• Have a narrower arc shape
• Can handle more amperage without eroding

Sharper electrodes with smaller included angle provide:

• Offer less arc weld
• Have a wider arc
• Have a more consistent arc

The included angle determines the weld bead shape and size. Generally, as the included angle increases, penetration increases and bead width decreases.

TIG Tungsten Selection Guide

This information is intended to act as a guide only, individual results may vary depending on technique, skill and material.

Tungsten Electrodes Rating for Welding Currents

TIG Troubleshooting

1. Tungsten burning away quickly
   • Incorrect gas or no gas: Use pure argon. Check cylinder has gas, connected, turned on, and torch valve is open.
   • Inadequate gas flow: Check the gas is connected, check hoses, gas valve and torch are not restricted.
   • Back cap not fitted correctly: Make sure the torch back cap is fitted so that the O-ring is inside the torch body.
   • Torch connected to DC+ : Connect the torch to the DC- output terminal.
   • Incorrect tungsten being used: Check and change the tungsten type if necessary.
   • Tungsten being oxidised after weld is finished: Keep shielding gas flowing 10-15 seconds after arc stoppage.
2. Contaminated tungsten
   • Touching tungsten into the weld pool: Keep tungsten from contacting weld puddle. Raise the torch so that the tungsten is off of the work piece 2-5mm.
   • Touching the filler wire to the tungsten : Keep the filler wire from touching the tungsten during welding, feed the filler wire into the leading edge of the weld pool in front of the tungsten.
3. Porosity – Poor weld appearance and colour
   • Wrong gas / poor gas flow / gas leaks: Use pure argon. Gas is connected, check hoses, gas valve and torch are not restricted. Set the gas flow between 8-12 L/min. Check hoses and fittings for holes, leaks etc.
   • Contaminated base metal : Remove moisture and materials like paint, grease, oil, and dirt from base metal.
   • Contaminated filler wire: Remove all grease, oil, or moisture from filler metal.
   • Incorrect filler wire: Check the filler wire and change if necessary.
4. Yellowish residue/smoke on the alumina nozzle & discoloured tungsten
   • Incorrect gas: Use pure argon gas.
   • Inadequate gas flow: Set the gas flow between 8-12 L/min flow rate.
   • Alumina gas nozzle too small: Increase the size of the alumina gas nozzle.
5. Unstable arc during welding
   • Torch connected to DC+: Connect the torch to the DC- output terminal.
   • Contaminated base metal: Remove materials like paint, grease, oil, and dirt, including mill scale from base metal.
   • Tungsten is contaminated : Remove 10mm of contaminated tungsten and re-grind the tungsten.
   • Arc length too long: Lower torch so that the tungsten is off of the work piece 2-5mm.
6. Arc wanders during welding
   • Poor gas flow: Check and set the gas flow between 8-12 L/min flow rate.
   • Amperage too low: Increase the amperage.
   • Incorrect arc length: Lower torch so that the tungsten is off of the work piece 2-5mm.
   • Tungsten incorrect or in poor condition: Check that correct type of tungsten is being used. Remove 10mm from the weld end of the tungsten and re-sharpen the tungsten.
   • Poorly prepared tungsten: Grind marks should run lengthwise with tungsten, not circular. Use proper grinding method and wheel.
   • Contaminated base metal or filler wire: Remove contaminating materials like paint, grease, oil, and dirt, including mill scale, from base metal. Remove all grease, oil, or moisture from filler metal.
7. Arc difficult to start or will not start welding
   • Incorrect machine set up: Check machine set up is correct.
   • No gas, incorrect gas flow: Check the gas is connected and cylinder valve open, check hoses, gas valve and torch are not restricted. Set the gas flow between 8-12 L/min flow rate.
   • Incorrect tungsten size or type: Check and change the size and or the tungsten if required.
   • Loose connection: Check all connectors and tighten.
   • Earth clamp not connected to work: C onnect the earth clamp directly to the workpiece wherever possible.

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