How To Select and Prepare Tungsten Electrodes For Your Application

To those of us who may not be aware, tungsten is an uncommon metallic element that is used in the manufacturing of TIG (or GTAW) electrodes. The TIG electrodes demand the type of hardness and high temperature resistance that tungsten alone can provide. This is because tungsten electrodes are meant to carry the welding current to the arc. It is to be noted that tungsten has an inconceivably high melting point when compared with other metals.

These electrodes come in different sizes and lengths and are available either as pure tungsten or a hybrid of tungsten mixed with other rare earth elements and oxides. Choosing the right electrode depends on the type and thickness of the base material and whether you are going to weld with alternating or direct current.

Please know that pure tungsten electrodes are expected to contain nearly 100% tungsten and have the maximum consumption rate of all electrodes. Tungsten electrodes are strangely less costly than its alloyed counterparts. These electrodes form a balled tip when heated and provide great arc stability for AC welding with balanced wave. Pure tungsten also provides good arc stability for AC sine wave welding - for aluminum and magnesium welding.

Thoriated tungsten electrodes (Color Code: Red) contain a minimum of 97.30% tungsten and balance thorium. These electrodes are the most widely used electrodes and are known for longevity and easy use. Thorium is highly useful in increasing the electron emission qualities of the electrode. Thus, it improves arc starts and enables a higher current carrying capacity. It also results in a lower level of weld contamination than other electrodes.

Ceriated tungsten electrodes (Color Code: Orange) contain a minimum of 97.30% tungsten and balance cerium. These electrodes are known to perform remarkably well in DC welding at low current settings. With its excellent arc starts at low amperages, ceriated tungsten are widely used as orbital tube and pipe manufacturing, thin sheet metal work or jobs where small and delicate parts are welded.

Lanthanated tungsten electrodes (Color Code: Gold) contain a minimum of 97.80% tungsten and balance lanthanum. These electrodes are known for their excellent arc starting as well as arc stability, low-burn-off rate and quick re-ignition capabilities. The fact is, in select cases, lanthanated tungsten electrodes can replace 2% thoriated without having to make significant welding program changes.

Zirconiated tungsten electrodes (Color Code: Brown) contain a minimum of 99.10% tungsten and balance zirconium. Zirconiated tungsten electrode is capable of stable arc and it resists tungsten spitting. The added feature is its current carrying capability which is equal if not more than thoriated tungsten. Zirconiated electrodes are unsuited for DC welding.

Rare earth tungsten electrodes (Color Code: Gray) contain unspecified additions of rare earth oxides or a mixture of different oxides. However, manufacturers will indicate each additive and its percentage on the outer label. Depending on the additives, you can obtain a stable arc in both AC and DC processes as also more longevity.

Finally, it may be said that the arc quality and welding performance you achieve will largely depend on the type and shape of tungsten you use. Each of these six types of tungsten has its own merits and shortcomings. It is therefore critically important you choose the right tungsten appropriate for each application.

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Maintenance Care For Your Plasma Cutter

Welding is an occupation where mistakes cannot be undone. Therefore inspecting well prior welding is essential to avoid undesirable mistakes. If you are really sure of what you are welding and are confident of the process then it can aggravate any costly errors that might have happen otherwise. The following maintenance care can aid you be devoid of the errors that you might encounter in plasma arc cutting;

Replace Consumable Parts as required:
Any electrical equipment needs to be maintained in the right manner. Replacement of consumable on a regular basis is very vital. They will lead to a cost effective usage of the cutter than having to replace the torch. Torch can be affected severely if there are parts in your plasma cutter that are worn out terribly.

Correctly Assemble the Torch:
Torches are supposed to last for a long period of time with proper maintenance. The torch ought to be put together in the right place so that the parts are in suitable configuration. This promises excellent electrical contact and the proper flow of gas and coolant all the way through the torch. Additionally, the torch threads must be unsoiled and seating areas ought not to have any particulate ineffectively. When altering parts, consumables ought to be set aside on a dirt free shop rag to avoid dirt or metal grime from polluting the torch.

Use the right Parts for the Job:
Choose the consumable depending upon the cutting amperage of your plasma cutter and the gas that you use for each job. The user's handbook defines which consumables are suitable for different types of cutting. If you use the incorrect consumable then it may lead to low cut quality and loss of years in the life span of the consumables.

Ensure appropriate Gas and Coolant Flow:
Check the flow of gas and pressure of coolant daily. Insufficient flow will lead to lessening of the life span of the consumables as they will no longer effectively cool the consumables. Excess gas pressure leads to hard starting i.e., the torch fails to perform while the rest of the consumables are working.

Shun Arc Stretching:
Stop stretching your arc to reach the metal. This will affect the parts impulsively. While you try piercing, locate the standoff to two times the height used for cutting. If otherwise, arc transfer might take place. Proper arc timing will lead to the weld without having the necessity stretching it.

Clean the Torch regularly:
It is very vital to keep cleaning the torch of your plasma cutter regularly. Even signs of pollution should be eradicated at once. Torch threads should be kept crystal clean, this include both external and internal threads. Hydrogen peroxide is a great chemical that does wonders in keeping your torch dirt free.

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What Are The Guidelines For Welding Cast Iron?

Welding cast iron calls for some special procedure. Welding cast iron is a challenging task and there can be no two opinions about that. Cast iron, unlike most other steels, has much greater carbon content at 2 to 4 percent. This causes most cast iron to be brittle making it difficult to weld. If the following procedure is followed, cast iron can be welded with relative ease:

Use either cooling or heating while welding cast iron as it is important to keep cast iron out of the 150- to 500-degree F range. Preheating is widely preferred, but there are times when cooling are also done. But stick to either cooling or heating and do not attempt to change in the middle of a weld.

Though preheating the cast iron part should suffice, it is preferable to preheat the entire casting slowly and uniformly in the 500- to 1,200-degree F range. Be very careful to heat within the stated range as overheating may cause cast iron to crack. The casting should get hot just to the extent you can to touch it comfortably with your bare hand. If need be, make short welds intermittently to avoid overheating.

Occurrences of small cracks when welding cast iron, is inevitable. You can apply some sealing compound to prevent leakages. If there are major cracks you must repair with studding. Studding is a complex process calling for a lot of skills. The first step is to drill and tap holes on the surface that has beveled. The next step is to put in steel studs and the studs should come out 5 to 6 mm above the surface and the studs should then be welded to remain in place.

Preheated welding can be easily done - particularly for small and manageable objects. While welding the cast iron without preheating, it is extremely essential the operator has good control over the welding gun and make the welds as small as possible.

Welding cast iron with an arc welder calls for different procedure. As a matter of fact, persons capable of welding cast iron with arc welder are few in number and there is a great demand for such skilled persons.

You may have to either purchase or hire a SMAW (shielded metal arc welding or stick electrode) welder depending how often you do cast iron welding with arc welder. Plug your welder into a 220V outlet and then plug in your ground cord and welder electrode holder cord into the welder. Please know that to weld cast iron, you need a special electrode. You may buy a 770 stick electrode to weld cast iron.

First of all, clean the surface area to be welded with a wire brush. Clamp the grounding clamp cord from the welder onto the piece of cast iron that has to be welded. Thereafter, place an electrode into the welder electrode holder and position the electrode near where the weld has to begin.

Continue to tap the electrode on the cast iron till an arc is created and begin to weave the electrode stick from side to side. Make it a point to keep the arc slightly away from the piece of steel you are welding. Wait for a few minutes for the weld to cool off gradually. Use the welding hammer to chip off the slag from the top of the weld.

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Introduction to Plastic Welding

Plastic welding and spot welding - both are almost similar to each other. There is a difference noted. In plastic welding, heat is supplied through convection of the pincher tips, instead of conduction. The two plastic pieces are brought together. At the time of welding, a jet of hot air is liberated. This melts the parts to be joined along with the plastic filler rod. As the rod starts melting, it is forced into the joint and causes the fusion of the parts.

Plastic identification is the first point to be noted in order to choose a suitable plastic welding rod. A plastic welding rod or thermoplastic welding rod is of a constant cross-section shape. Using this, two plastic pieces can be joined. It may have a circular or triangular cross-section. Porosity of the plastic welding rod is an important factor. Air bubbles in the rod will be created due to its high porosity. This is responsible for decreasing the quality of the welding. So, the rods used must maintain zero porosity. Otherwise, they should be void less. Products like chemical tanks, water tanks, heat exchangers and plumbing fittings are manufactured by using the technique of plastic welding. By adopting this technique, money can be saved.

Using plastic welding, two plastics can be welded together. This type of weld is performed on children's toys, lawn furniture, auto parts and other plastic equipments which are used daily - both for domestic and commercial purposes. In order to join the thermoplastics, when they are heated an under a particular pressure, this type of welding is employed. In normal practice, using filler material, the pieces are joined together. There are certain occasions wherein filler material can be avoided. Generally, plastic is not durable and has a shorter life span. Natural elements like cold weather, ultraviolet radiation from the sun or continuous exposure to chemicals causing contamination, will create damage to plastic products. Plastic can be subjected to damage if it is hit on a hard surface. But, as the price of new parts is high, it is preferred to repair the existing products.

As there are different types of plastics, we must know which one we are working with in order to find the exact welding material to be used. We must know the difference between thermoplastics and thermo sets because it is not possible to weld thermo sets. If you use the wrong welding rod for the plastic to be repaired, bonding will not take place. As materials like polyolefin's have a lower surface energy, a special group of polyolefin adhesives has to be used. When you are repairing plastic, there are usually two types of defects - a crack or a broken part. In the case of a crack, there is a particular stress affecting the inside of the material. You have to repair the crack and you should not continue through the piece.

There are many types of plastic welding.

* Hot gas welding uses a welding gun which has electric heating elements. They produce heat f hot gas.
* Hot plastic welding uses a hot plate place between the two surfaces which are to be joined. In order to weld two pieces, ultrasonic welding uses a high frequency acoustic vibration. After subjecting them to high pressure, they are exposed to the vibrations until the weld is completed.
* Spin welding, where friction is employed to weld two cylindrical parts. These parts are rotated. The rotation stops at a particular point and the weld is completed.
* Vibration welding exposes the pieces to a frequency called amplitude. The two pieces are subjected to pressure due to which a friction is created which generates heat.

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Underwater Welding

Welding is an unavoidable process of modern engineering – civil, electrical, mechanical, automobiles, marine aeronautical – in all branches. It is used in fabrications and erections in infrastructures and installations. It joins metals or thermoplastics. Forming a pool of molten mass – the weld puddle – and allowing it to cool to become a strong joint is the basis of the process of welding. For repairing to be carried out underwater, there is a separate process. That is called underwater welding. If damaged ships are to be repaired, underwater welding is the basic technology to be used. It is a highly-specialized profession – more employed in the oil or shipping industry and also in the defense operations.

Underwater welding process is categorized into two divisions.

• Wet welding
• Dry welding

Wet welding:

In the case of wet welding, the operation is completed under water, directly exposed to the wet environment. For this purpose, a different type of electrode is used. The function is carried out manually. The welder is allowed to have freedom of movement. Hence, wet welding is the most effective, efficient and economical process.

The welding power and supply unit is placed on the surface and is connected to the welder with the help of cables and hoses.

The Advantages:

* The expenditure is very minimal. Unlike in the case of dry welding.
* The speed of the operation is extremely high.
* As the equipments are very minimum, the welding can be performed in a shorter time with minimal planning.

The Disadvantages:

* The weld is quenched is very fast under water. It decreases the ductility and impact strength an also makes the weld very porous.
* The visibility of the welder is not up to the required level.
* The amount of voltage that can b employed is very limited. Care has to be taken so that the welder is not harmed by probable electrical shocks.

Dry Welding:

In case of dry welding, otherwise known as Hyperbaric welding, the whole operation is completed in a chamber, sealed around the structure to be welded. The chamber is filled with gas – normally helium – containing 0.5 bar oxygen. The chamber is fitted onto the pipeline and is filled with the breathable mixture of air. The operation is carried out in higher pressure. The gas tungsten arc welding process is used.

The Advantages:

* Welding can be carried out without getting affected by ocean currents and marine animals.
* Better quality welds can be used.
* From the surface itself, there is a possibility of visually monitoring joint preparation and pipe alignment.

The Disadvantages:

* The chamber is very complex. Large support equipment is needed at the surface to support the chamber.
* The expense will be very high. The cost increases proportionately to the depth under water.
* The chamber has limited reusability.

Risks & Precautions:

Both the welder and the structure are at risk. The welder has to protect himself from electric shocks. The welder has to be insulated. The voltage of the welding sets has to be controlled. Pockets of oxygen and hydrogen built up by the arc will be potentially explosive. The welder has to take precaution because nitrogen will be built up in the blood stream of the welder, when exposed to air at high pressure under the water surface. Inspection, although very difficult, is a mandatory requirement. No defects should remain. In addition to all these precautions, safe arc-welding precautions are to be taken.

Underwater welding is mostly employed in marine engineering products – in installations of oil and gas rigs. Underwater welding can be classified depending upon the types of equipments and the types of procedures involved. The most common underwater welding process, known as manual metal arc building (MMA), is employed for deep water repairing activities. Cofferdam welding process and Hyperbaric welding process are normally carried out for underwater welding operations. They are employed for welding steel pipelines, other offshore structures, submerged parts of large ships and underwater structures supporting a harbor. The safety measures include emergency air or gas supply, stand-by divers and decompression chambers.

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Mig Welding: An Overview

Welding is a difficult job. It is very important to be well prepared before you start welding. Every welder that is being purchased comes with an instructional manual. This manufacturer’s book of precautions should be strictly adhered to. More Info Visit: http://www.everlastgenerators.com/

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Making Of Portable Welding Screens

It is common knowledge that welding work is prone to cause physical injuries and eyesight problems due to sparks and excessive heat and a welder has to necessarily invest in safety gadgets to keep not only himself but also others around him safe. More Info...

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Generator- An Emergency Power Source

Most of us do not know the importance of electricity until it’s not available. Power cuts are not predictable, it could occur at any moment. Electricity plays an important role in all sorts of business. More Info...

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TOP 3 - Welding Equipment

The job of a welder can be dangerous, unless there is strict adherence to all safety measures. Although the task at hand is hazardous, there are five important pieces of Welding equipment every welder must have. More Info...

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Overview of TIG (Tungsten Inert Gas) Welding

TIG welding has had many names and because it started in the 1941s many older welders may refer to it as “heliarc” welding. This welding was initially used in the war efforts to weld airplanes because it did a good job on aluminum, magnesium, and stainless steel. More Info

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Looking Back At The History Of Welding

It is said that the history of welding can be dated back as far as the Bronze Age or 3300 BC. It was during this time that there was evidence found of the weld taken place, creating objects for citizens back then to use. More Info

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Consumable Plasma Cutters - Pros & Cons

A plasma cutter is a device which can cut through a metal using super heated gases emitted from its nozzle. Thy can focus approximately 30,000 degrees Fahrenheit of heat in the tightly-focused emission, cutting into the thickest metals in moments. They are also known as plasma torches. More Info

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Basic Welding Equipment and Welding Safety

Welding is a highly developed skill that most people continue to develop over time. Depending on the type of welding you choose to learn there will be equipment that you need and precautions to keep you safe. More Info...

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The Basics of the Arc Welder

This is an article on the basics of Arc welding and its equipment.Arc Welding occurs when powerful heat starts to melt the metal, this causes an electric arc.More Info...

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Plasma Cutting Tips for Successful Plasma Cutting

There are many ways to weld and when you need high heat plasma cutting is your best way to do it. You will find that plasma and the plasma arc process has been refined so you can get a better quality cut at higher speeds with a lower cost. More Info....

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Why Diesel Generators?

Diesel generators have longer life when compared to other types of fuel (natural gas or gasoline). Acquisition and maintenance cost is less when compared to natural gas. Natural gas require spark ignition while diesel generators are operated by using compression ignition.More Info...

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What Are Silent Diesel Generators?

Residential, marine and RV generators have special materials and designs that keep the noise low produced by generators. No person wants to listen to a high whirling noise all day on a boat, RV or sitting there at home. more info

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Fundamentals of Arc Welding

Arc welding is one of the most popular types of welding. In simple terms, welding is a fusion process for joining metals. Metals should be melted together with extreme heat and fuse as one piece.

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All About Air Plasma Cutters

When you think of a machine that can do most of your repair jobs, efficiently and cleanly, you may want to make sure that you have an air plasma cutter, handy. It will be the air plasma cutter that can cut with a precision that is, unmatched. They are capable of cutting at extremely high speeds, helping you save both, time and money.

This machine has the ability to cut the sharpest of corners. They can cut most steels and metals with ease and at high speeds, aiding in higher production rates for business owners. There are some plasma cutting devices that can actually cut metal in designs once thought, impossible.

This machine can blow air at an extremely high rate from its nozzle creating an electrical arc. This arc is formed when the heated air becomes hot enough to melt the steel or any metal material. This air is compressed which makes it flow very fast from the torch, slicing the material in a highly polished look.

There are several components that start up the pilot for the electrical arc or light most see when it is engaged. There is the on contact start up method, which will spark, once it comes in contact with the material. There is another common method that will spark the arc once the nozzle and the electrode have come into contact.

Either method has its own safety precautions. With either method, you must use care because there are risks involved for the operator. The operator may be electrocuted or come in contact with vast amounts of emissions. As with any procedure, they must make sure they inspect their equipment for defects, before using it.

Once they have sparked their torch, they are ready to begin cutting their material. Depending on how thick or thin the source material is, will determine which type of torch is needed. The torch itself isn’t the only piece of equipment to determine the outcome of the job, so is the nozzle.

The nozzle in recent times has been developed for much smaller arcs. These nozzles will help with detailed cutting needs that must be of the highest of quality. These nozzles are helpful to manufacturers in cost, being that once worked there isn’t much left to be finished. This will save in material and clean up.

The air plasma cutter and other cutting systems aren’t as costly as they once were. They aren’t as expensive for the shop owner or manufacturer. These machines have become extremely popular and are now even found their way to many people who need them in their homes. They were once only available to those in the bigger industrial type settings, but now can be found in someone’s backyard dwelling or shed.

They are available in several portable models, making them even more convenient to use. It is the air plasma cutter, that will help you because of their lighter designs. They have even been made more ergonomically for ease on the body of the operator. They are durable and will bring you the highest in quality when it comes to your metal that you cut.

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Overview on Diesel Generators

Diesel generators can be used for domestic, industrial and commercial purpose. These are not only used as a primary power sources but also as standby/back power sources. Being made in various sizes and configurations, they can be built to your exact specifications. Diesel generators are an extremely versatile and cost effective power solution.

Life expectancy for liquid cooled 1800 rpm engines can be 20,000 hours if properly serviced. These can be operated in cold conditions. It can work better if loaded for a long period of time. During disaster situation, it can be used by military, truck industry or farm operations. Cost for this type of generator is much lower when compared to gaseous powered engines.

People prefer Diesel generators for following reasons:
• Quiet operation
• Less maintenance
• Rugged and durable
• No spark plugs
• Longer life

Some of the factors that you have to consider before purchasing a diesel generator are:

• How much power do you need?
• Will you use it for emergency purpose or prime application
• Noise level
• Kind of power needed- single phase or three phase
• What kind of use and environment will the generator be

subjected to –heat, humidity, altitude, dust levels and power loads all have a direct effect on generator performance and life.

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