A: Gouging is necessary for many tasks related to welding when the operator is trying to remove material to get to clean metal. The most obvious use of gouging is to remove large amounts of metal or welds that need to be repaired.
What is gouging in welding?
PCES UK. Gouging is the term to define a type of corrosion which occurs on a metallic surface in which a hole, groove or indentation is created. In welding, gouging has been a requirement for many years in several industries and applications – and is one method to scrutinise.
What is the difference between MMA welding and gouging?
Unlike MMA welding where a stable weld pool must be maintained, this process forces the molten metal away from the arc zone to leave a clean cut surface. The gouging process is characterised by the large amount of gas which is generated to eject the molten metal.
What is back GOUGE welding?
The removal of weld metal and base metal from the other side of a partially welded joint to assure complete penetration upon subsequent welding from that side. How common are Back Gouge welds in jobs today?
What are the applications of metal arc gouging?
Typical applications include back gouging, removal of surface and internal defects, removal of excess weld metal and preparation of bevel edges for welding. The main advantage of manual metal arc (MMA) gouging is that the same power source can be used for welding, gouging or cutting, simply by changing the type of electrode.
What are gouging rods used for?
Gouging electrodes are made of carbon and have a copper coating. Gouging carbon rods are used for metal removal at fast rates with low power consumption. It is generally used to remove welding defects, excess welds and foundry risers from cast products.
What is the gouging?
What Does Gouging Mean? Gouging is a type of corrosion that occurs on a metallic surface in which a hole, groove or indentation is created. Gouging happens in boiler tubes because of caustic corrosion that occurs as a result of excessive use of alkalines such as sodium hydroxide (NaOH).
What is gouging in fabrication?
Thermal gouging is an essential part of welding fabrication. Used for rapid removal of unwanted metal, the material is locally heated and molten metal ejected - usually by blowing it away. Normal oxyfuel gas or arc processes can be used to produce rapid melting and metal removal.
What do you need for arc gouging?
0:178:11Arc Gouging Basics (Part 1): Machine Setup - YouTubeYouTubeStart of suggested clipEnd of suggested clipIt requires an air source it requires carbon arc electrodes. And the air is shot out of some holesMoreIt requires an air source it requires carbon arc electrodes. And the air is shot out of some holes down here at the bottom we strike an arc with an electrode. And the air displaces.
What are the types of gouging?
Common methods of gouging are mechanical techniques such as grinding, hand milling, routing, and chipping; oxyfuel gouging, which can be used only on carbon steels; and air carbon-arc gouging. The plasma cutting process was invented in 1954 at the Tonawanda Laboratory of the Linde Division of Union Carbide.
What is mechanical gouging?
Mechanical gouging methods—grinding, hand milling, routing, and chipping—are widely used. These methods are suitable for metalworking shops, but typically they are slow and often loud. Oxyfuel Gouging. Oxyfuel gouging is a common thermal or chemical method and a variation of oxyfuel welding and cutting.
Why is back gouging needed?
Back gouging is a process of cutting a groove in the back side of a joint that has been welded. Back gouging can ensure 100% joint fusion at the root and remove discontinuities of the root pass. This process can also remove the root pass metal if the properties of the metal are not desirable to the finished weld.
How do you do gouging?
Gouging is commenced by striking the electrode tip on to the workpiece surface to initiate the arc. Unlike manual metal arc (MMA) welding the electrode tip is not withdrawn to establish arc length. Molten metal directly under the electrode tip (arc) is immediately blown away by the air stream.
How do you use a gouging electrode?
0:108:06Arc Gouging Basics (Part 2): Proper Torch Angle - YouTubeYouTubeStart of suggested clipEnd of suggested clipThat can be used for procedures where we're getting full penetration. We do a partial penetrationMoreThat can be used for procedures where we're getting full penetration. We do a partial penetration weld on one side we turn it over we back gouge down to clean metal grind. Clean complete the weld.
How does metal gouging work?
Air carbon arc gouging is a process of removing metal by means of heat generated from a carbon arc. The process uses a carbon/graphite electrode, compressed air and a standard power source. The intense electric arc used between the tip of a carbon electrode and a metal work piece cuts and melts the work piece.
What is carbon gouging?
Carbon-arc gouging is a melting operation, where metal is removed from the surface by the arc pressure or force. Direct current (DC) is used and the electrode is graphite coated with a layer of copper to assist conductivity. Most materials may be gouged by the process, but the cut is usually wide and ragged.
Can you gouge without air?
ZENA NO-Gas arc cutting/gouging rods let you gouge, bevel, and cut metal without needing a 300+ Amp air-arc gouging/cutting rig or an acetylene cutting torch and bulky gas bottles.
What is gouging welding?
Gouging is the term to define a type of corrosion which occurs on a metallic surface in which a hole, groove or indentation is created. In welding, gouging has been a requirement for many years in several industries and applications – and is one method to scrutinise.
How does carbon gouge work?
The metal becomes molten and a high velocity air streams down the electrode to blow it away and thus leaves a clean groove. It is a simply process to apply, has a high metal removal rate and gouge profile can be closely controlled. However, there are disadvantages: the air jet causes the molten metal to be ejected over quite a large distance and, because of high currents (up to 2000A) and high air pressures (80 to 100 psi), it can be very noisy.
What is MMA gouge?
The MMA gouging process is characterised by the large amount of gas which is generated to eject the molten metal. However, because the arc/gas stream is not as powerful as a gas or a separate air jet, the surface of the gouge is not as smooth as an oxyfuel gouge or air carbon arc gouge.
What is the advantage of MMA welding?
The main advantage of manual metal arc (MMA) gouging is that the same power source can be used for welding, gouging or cutting, simply by changing the type of electrode. The arc is formed between the tip of the electrode and the workpiece in conventional MMA welding.
Why is air jet gouging so noisy?
However, there are disadvantages: the air jet causes the molten metal to be ejected over quite a large distance and, because of high currents (up to 2000A) and high air pressures (80 to 100 psi), it can be very noisy. This type of gouging can be applied to a wide range of metals.
What is the difference between AC and DC welding?
DC (electrode positive) is normally preferred for steel and stainless steel, but AC is more effective for cast iron, copper and nickel alloys. Typical applications include back gouging, removal of surface and internal defects, removal of excess weld metal and preparation of bevel edges for welding.
What is a gouging torch?
A manual gouging torch and cable assembly includes connections for the welding lead and compressed air line. Be sure to size the torch and ground cable appropriately based on amperage and length of the cable. An insulated connection boot and hookup kit simplifies torch hookup and eliminates the possibility of arcing when contacting electrically hot parts.
What is the name of the company that makes gouging equipment?
Stepath did his original work with the Navy during World War II before founding Arcair Co. in 1949. Today, Arcair is part of the ESAB family of brands, and the name Arcair is synonymous with the gouging process.
What electrodes are used in carbon arc gouging?
DC copper-coated electrodes are the most widely used in air carbon-arc gouging because of their comparatively long life and stable arc characteristics. The depth and contour of the groove produced are controlled by the electrode diameter and travel speed.
How to strike an arc?
Strike an arc. Strike an arc by lightly touching the carbon electrode to the workpiece. Let the arc start and slowly move it forward or side to side as needed to accomplish the goal. Striking the arc is a little bit different and slightly easier than with a welding electrode.
What does muffled arc mean?
A muffled arc means the voltage is too low, which could result in carbon deposits. 5. Angle of travel. Hold the torch so that the carbon electrode slopes back from the direction of travel with the air blast blowing past the tip of the electrode to evacuate the molten metal.
Can you cut carbon steel with carbon arc?
In fact, most common metals (carbon steel, stainless steel, high-alloy wear plate, copper alloys and cast irons) can be cut using air carbon-arc gouging. An operator uses the air carbon-arc gouging process to back-gouge a weld on a barge. Typical applications include the back-gouging of weld seams to reach the deposited weld metal from ...
Who invented carbon arc gouging?
The inventor of carbon-arc gouging, Myron Stepath, originally developed the process for removing defective welds in stainless steel armor plate on U.S. warships; conventional methods such as chipping and grinding proved unfeasible due to time and cost factors.
Q1: When is gouging used?
A: Gouging is necessary for many tasks related to welding when the operator is trying to remove material to get to clean metal. The most obvious use of gouging is to remove large amounts of metal or welds that need to be repaired.
Q2: Can I gouge in CV mode?
A: You can gouge in constant voltage (CV) mode, but it will result in a shallower penetration profile that is wider and flatter than gouging in constant current (CC) mode.
Q3: How do I know what size of electrode to use for gouging?
A: Gouging electrodes are available in a range of sizes, so understanding your machine’s capabilities is key to avoid using too large of an electrode. The spec sheet or owner’s manual for some machines will specify the electrode diameter ranges that can be run and list the maximum electrode size that can be used for carbon arc gouging.
Q4: What are the advantages of using electrodes of different geometries for gouging?
A: Typical cylindrical electrodes, also known as pointed electrodes, are best for all-purpose gouging. Flat electrodes are good for achieving a flush surface, as in removing weld reinforcement or creating rectangular grooves.
Q6: Why should I use a machine with a dedicated gouging process?
A: Gouging is a process just like stick or MIG welding. Just as with those welding processes, technology in Miller engine-driven welder/generators and plug-in welding power sources that include a gouging mode has resulted in optimized gouging performance. Reference the owner’s manual for your power source to find the gouging setup, if applicable.
Q7: Are inverter-based welding power sources bad for gouging?
A: While this used to pose a problem with older inverter machines, today’s inverter-based power sources from Miller have been engineered, designed and tested for the gouging process, providing exceptional reliability and operation.
Understanding carbon arc gouging
Carbon arc gouging is an important part of many welding applications — from structural steel construction to field repairs. Understanding the gouging process and how to choose the right equipment and electrodes for the job can help improve efficiency and optimize results with this process.
What is air carbon arc gouging?
Both plasma arc gouging and air carbon arc gouging are methods that require electrical power. In cases where diesel or gas powered generator are accessible, the process becomes more portable.
What is the best tool for back gouging?
When the metal isn’t too thick, it doesn’t take too long and doesn’t require a lot of gouging – an electric or air grinder is sometimes an ideal tool when it comes to back gouging. Based on the configuration of the joint, either a thick or a thin coarse or rough disc may be the ideal tool to get the task done.
What is CJP weld?
The term Complete Joint Penetration (CJP) is how it is referred in the industry. In most cases, these welds are to be completed only from one side, requiring some kind of root pass on an open root joint unlike other applications where access is possible to the entire backside where an open root pass kind of weld is not required.
What is the least protection for the face when using a grinder?
The least protection for the face is a face shield and safety glasses.
Can you weld from one side?
In most cases, these welds are to be completed only from one side, requiring some kind of root pass on an open root joint unlike other applications where access is possible to the entire backside where an open root pass kind of weld is not required. When a full penetration weld needs to be completed where both sides are going to be welded, ...
Can you use a grinding wheel on an edge?
Moreover, since many of the grinding wheels are not meant to be used on the edge, ensure that it is ok to use your wheels for this particular application. Remember – always, safety first!! In case the metal is larger, thicker or if the gouge is lengthy or in a tight position then the grinder may not be the answer.
Why is MMA gouge used?
MMA gouging is used for localised gouging operations, removal of defects for example, and where it is more convenient to switch from a welding electrode to a gouging electrode ...
What is MMA welding?
The main advantage of manual metal arc (MMA) gou ging is that the same power source can be used for welding, gouging, or cutting, simply by changing the type of electrode. As in conventional MMA welding, the arc is formed between the tip of the electrode and the workpiece. MMA gouging differs because it requires special purpose electrodes ...
What is TWI in cutting?
TWI is noted for its experience on Health and Safety about fume (and hazards) emanating from cutting processes. TWI can help your company developing, supervising/implementing and providing guidance on specialist cutting procedures for a wide range of applications across all industry sectors.
Can MMA gouge stainless steel?
However, when gouging stainless steel, a thin layer of higher carbon content material will be produced; this should be removed by grinding.
