Welder

This is about welding

as a trade. For the machine used to power arc welding procedures see welding power supply.
A welder (also weldor, which term distinguishes the tradesman from the equipment used to make welds) is a tradesman who specialises in welding materials together. The materials to be joined can be metals (such as steel, aluminum, brass, stainless steel etc.) or varieties of plastic or polymer. Welders typically have to have good dexterity and attention to detail, as well as some technical knowledge about the materials being joined and best practices in the field.

Safety issues
Welding, without the proper precautions appropriate for the process, can be a dangerous and unhealthy practice. However, with the use of new technology and proper protection, the risks of injury and death associated with welding can be greatly reduced. Because many common welding procedures involve an open electric arc or flame, the risk of burns is significant. To prevent them, welders wear personal protective equipment in the form of heavy leather gloves and protective long sleeve jackets to avoid exposure to extreme heat and flames. Additionally, the brightness of the weld area leads to a condition called arc eye in which ultraviolet light causes the inflammation of the cornea and can burn the retinas of the eyes. Goggles and welding helmets with dark face plates are worn to prevent this exposure, and in recent years, new helmet models have been produced that feature a face plate that self-darkens upon exposure to high amounts of UV light. To protect bystanders, transparent welding curtains often surround the welding area. These curtains, made of a polyvinyl chloride plastic film, shield nearby workers from exposure to the UV light from the electric arc, but should not be used to replace the filter glass used in helmets.

Welders are also often exposed to dangerous gases and particulate matter. Processes like flux-cored arc welding and shielded metal arc welding produce smoke containing particles of various types of oxides, which in some cases can lead to medical conditions like metal fume fever. The size of the particles in question tends to influence the toxicity of the fumes, with smaller particles presenting a greater danger. Additionally, many processes produce fumes and various gases, most commonly carbon dioxide and ozone, that can prove dangerous if ventilation is inadequate. Furthermore, because the use of compressed gases and flames in many welding processes pose an explosion and fire risk, some common precautions include limiting the amount of oxygen in the air and keeping combustible materials away from the workplace.

Welding

Welding is a fabrication process that joins materials, usually metals or thermoplastics, by causing coalescence. This is often done by melting the workpieces and adding a filler material to form a pool of molten material (the weld puddle) that cools to become a strong joint, with pressure sometimes used in conjunction with heat, or by itself, to produce the weld. This is in contrast with soldering and brazing, which involve melting a lower-melting-point material between the workpieces to form a bond between them, without melting the workpieces.
Arc welding

Many different energy

sources can be used for welding, including a gas flame, an electric arc, a laser, an electron beam, friction, and ultrasound. While often an industrial process, welding can be done in many different environments, including open air, underwater and in space. Regardless of location, however, welding remains dangerous, and precautions must be taken to avoid burns, electric shock, poisonous fumes, and overexposure to ultraviolet light.

Many different energy sources can be used for welding, including a gas flame, an electric arc, a laser, an electron beam, friction, and ultrasound. While often an industrial process, welding can be done in many different environments, including open air, underwater and in space. Regardless of location, however, welding remains dangerous, and precautions must be taken to avoid burns, electric shock, poisonous fumes, and overexposure to ultraviolet light.
Until the end of the 19th century, the only welding process was forge welding, which blacksmiths had used for centuries to join metals by heating and pounding them. Arc welding and oxyfuel welding were among the first processes to develop late in the century, and resistance welding followed soon after. Welding technology advanced quickly during the early 20th century as World War I and World War II drove the demand for reliable and inexpensive joining methods. Following the wars, several modern welding techniques were developed, including manual methods like shielded metal arc welding, now one of the most popular welding methods, as well as semi-automatic and automatic processes such as gas metal arc welding, submerged arc welding, flux-cored arc welding and electroslag welding. Developments continued with the invention of laser beam welding and electron beam welding in the latter half of the century. Today, the science continues to advance. Robot welding is becoming more commonplace in industrial settings, and researchers continue to develop new welding methods and gain greater understanding of weld quality and properties.

Welding Helmets to Protect your Eyes

Welding helmets are one of the most common accessories for someone engaged in welding. Indeed, the popular vision of the welder would not be complete without the helmet. Our national mythology includes the image of Rosie the Riveter and her welding sisters wearing welding helmets and protective face plating. But, what should you know about welding helmets before acquiring and using them? What common questions should you ask concerning welding helmets?
The first question to ask is what is the lens shade, and which one should be used for eye protection? A common misconception is that the lens shade number equates to the amount of protection given to the eyes. These people think that the higher the number, the more protection provided. Not so. The number, much like sunglasses, indicates the darkness provided the shade and should be used to select the most comfortable shade. Most welding experts suggest selecting a shade that lets you see the weld puddle most clearly and the one that helps you the most when welding.

The second common question is, that self-darkening helmets don’t start to darken until the welding arc is fired, giving a split second without apparent protection. Will this brief period lead to eye damage? The answer is that high quality helmets with auto darkening shades provide protection from both ultra violet and infrared radiation, even when the helmet is not yet activated.
The third question is, which type of helmet is better, battery powered or solar powered? The answer to this, as you might expect, is personal preference. Both type of helmets work fine.

Most battery-operated helmets have a feature that saves power by turning off the power after the helmet has been sitting idle for a while. So, for this reason a welder using a battery-powered helmet should pay attention and make sure that his helmet remains on to avoid arc burn. Also, some prefer the convenience of solar powered helmets because they are always on.

The fourth common question is should a welder choose a fixed shade or a variable shade? The answer is if a welder is always using the same arc welding process and using the same material each time, then a fixed shade if fine. But most welders use several types of materials and their welding duties entail many different welding applications. In this case, a variable shake will adjust for different conditions and be preferable.

Other features that should be sought in a welding helmet are: lightness of weight; a sensor bar that will limit the field of response to avoid having your helmet triggered by the guy next to you; full adjustability to provide a better fit – especially important for welders who wear glasses; quality and price.

Keep these questions and the corresponding answers in mind when picking out a welding helmet and you’ll have a piece of equipment that will help you professionally for many years to come. A welding helmet is one of the most important pieces of safety equipment, along with safety glasses and boots.

An Introduction to Welding

Welding is one of those construction niches that doesn’t get a lot of attention

but is absolutely critical to the completion of any metal structure. Here is an introduction to the subject. The field of welding is not really a totally modern career born in the Industrial Revolution. Pictures of welders and their ancient tools have been discovered in sealed Egyptian tombs. Welding is the process of joining metals through the use of heat and pressure. Many people credit developments in the art of welding as enabling many of the technological advances that marked the industrialization of the world.

In many cases welding involves temperatures that are incredibly high.

Steel, for example, melts at around 2,800 degrees Fahrenheit. Welding is a very essential part of just about every modern industry. In the year 2000, a total of over 34.1 billion dollars was spent on welding related costs in American industry alone. If you break this down, it amounts to around $325 per American household.
In 2004, 429,000 professional welders were engaged in welding related work in the United States. They were engaged in a wide variety of different work, but a large percentage of them were working in fields that were extremely vital to the economy and security of the country. The average age of these welding professionals was 54 years old. So, many of these will be reaching retirement age in the next ten years that the United States Department of Labor estimates a shortage of nearly 250,000 welders by 2010.

For the past two decades

the shift in the work force from blue collar to white collar has created a significant shortage in skilled workers. This is especially true of welders. The pendulum will have to shift soon. There will be such a shortage of skilled welders in the coming years as to create a serious industrial crisis. This has only opened up the field to young people looking for a secure and useful trade. Pay scales and benefits of the jobs have risen as a result of the shortage.

There are several different forms of welding used in industry today

The common types that use an "arc" to heat the metals to fuse them are Gas Metal Arc Welding (GMAW), Gas Tungsten Arc Welding (GTAW), and Shielded Metal Arc Welding (SMAW). Another type that does not use an arc, but rather electrical resistance and pressure is called Resistance Welding.

A Basic Overview of How MIG Welders Work

One of the most widely used types of welders is the MIG welder. The process of welding that a MIG welder uses is called gas metal arc welding (GMAW). These welders work by feeding a wire which is the electrode through a welding gun. At the same time there is a continuous flow of inert shielding gas. This protects the weld while it cools.

The most common gases used are carbon dioxide for general purpose welding. It is the cheapest of the welding gases, and creates a good weld. Argon and carbon dioxide is also used in a mixture to have a welding arc with less spatter, giving cleaner welds. Pure argon gas is used to obtain the best welds when welding aluminum.

The GMAW process have a number of advantages over the other common welding processes. The welding gun has a trigger to control the electrode which allows you to position it without accidentally striking an arc. When you have it in the correct place all you have to do is flip down your helmet and pull the trigger.

The inert shielding gases make the welds smooth and clean. There is no slag to chip off. MIG welders are also very well suited to weld sheet metal and thinner metals. This is because they can weld at lower amperage than most welders. MIG welders always use DC current to strike the welding arc. This is because using alternating current doesn't give you a steady arc.
On a MIG welder you can adjust the voltage, amperage and the speed at which the wire is fed through the welder. The tensioner on the welding wire is variable as well They will also have a valve to control the flow of gas.

It is also possible to use a mig welder without the shielding gas. This is called flux cored arc welding (FCAW). Most welders have the option of switching the polarity of the welding arc for use with flux cored wire. In this welding process the welding wire has a hollow core that is filled with flux.

Flux cored arc welding can be done outside, because there is no need to worry about the shielding gas being blown away. The flux core wire has a hotter arc and therefore can be used to weld thicker pieces of metal. The disadvantages of FCAW are that you have to remove the slag from the weld similar to welding with a standard stick welder. It cannot generally be used to weld thinner sheet metal and other light metals.

MIG welders can be used to weld aluminum, tin, copper, zinc and brass., and steel. There are dozens of different compositions of MIG welding wires to choose from. This means you can get the best combination for almost any welding situation. MIG welders are the ideal choice if you only want to buy one welder, and still be able to weld on a variety of metals. If you want to start welding, a MIG welder would probably be your best choice for a welder that is very versatile and easy to learn on.