Posts Tagged ‘TIG Welders’

GTAW Process: Shielding Gas and Regulator Selection

Friday, September 30th, 2011

There aren’t many choices available for shielding gas selection in TIG. It’s fairly straightforward. Pure Argon is the most popular and common shielding gas. Most people buy and use pure Argon in whether welding aluminum or steel. Unlike MIG, blends of CO2 and Argon cannot be used. If CO2 is used, it will contaminate the weld and will rapidly consume the tungsten. Often Argon can be contaminated with CO2 since the welding supply companies can use the same tanks to fill Argon and Argon blends. Helium and Argon are often blended, especially while welding Aluminum to increase penetration. Blends of Argon and helium are more expensive and some problems can be experienced since argon sinks and helium rises in the atmosphere. Also when too great of a helium percentage is mixed, arc starts can be erratic or make the arc unstable. The operator should be aware of which type gas is being used, because amp and flow settings will be different.

Not all regulators are equal. There is the floating ball type that visually regulates the gas flow and then there is the less expensive gauge type regulator. The floating ball is easier to see and read at a distance, and is a personal favorite. Both do a decent job of regulating the gas, but be sure to select a regulator that is calibrated for the gas or gas mix that you are using. Some will regulate both MIG gases and TIG gases. Some have dual or triple scales for several different blends. Blends high in helium require much higher flow rates. Also check whether the gauges are calibrated in Liters Per Minute (LPM) or Cubic Feet Per Hour (CFH).

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GTAW Process: Tungsten Selection

Monday, September 26th, 2011

TIG welding of course could not exist without the “T” in TIG. The “T” stands for tungsten. The tungsten is a small shaft of elemental tungsten used as a semi-permanent electrode to produce an electrical arc between the tungsten tip and the metal. Though considered a consumable, it does not consume at a rapid pace as in MIG or Stick welding. However, they will wear rapidly in hands of inexperienced users, through overheating, and constant immersion or “dipping” into the molten weld pool.

Tungsten can be offered as pure tungsten or combined with some other element to exhibit different welding characteristics. Along with each element, varying percentages of the secondary element can be offered. Each Tungsten with its own percentage of alloying metal carries its own color marking on the Tip, and is commonly referred to the color instead the actual components and percents. However, there are some variations in color from country to country. Much of today’s tungsten is imported, and different colors than the standard color can be expected.

Green tungsten is referred to as “pure” tungsten. Pure tungsten is traditionally used only with AC welding. However, with todays high performance inverter welder machines such as the Everlast PowerTig series welders, pure tungsten is a very poor choice. It will not last long and exhibits poor arc stability. Many websites and texts still recommend green tungsten for welding aluminum, borrowing recommendations from material written up to 50 years ago. This old information is confusing to many old and new welders, especially when the pure tungsten just melts away when it is stuck in an inverter machine. It’s still suitable for welding with transformer based welders, and is welded with a fairly large molten ball forming hanging on the end. It will not allow the pinpoint arc precision as some other tungstens, since the ball does not focus the arc and is subject to wander around the ball if proper technique is not used.

GTAW Tungsten Selection

GTAW Tungsten Selection

Thoriated Tungsten (2%) has been the standard for the welding industry in the United States for DC welding. Again, things have changed with the advent of inverter TIG welding systems. Commonly referred to as “Red” tungsten, it has excellent arc starting and overall welding capabilities. It can be used for AC or DC welding with inverter machines, such as the Everlast PowerTig 250EX. But it’s not the best choice for AC welding in transformer machine however, though it can be done. It can be sharpened to a fairly sharp point, and does not have to be balled while AC TIG welding aluminum. However, if overheated, it can split and form nodules on the side of the tungsten, creating a destabilized arc. One drawback of the thoriated, is that it is slightly radioactive. However, the radiation exposure is small compared to some other daily forms of radiation that exist. As long as the tungsten grinding dust is not breathed in, little risk, even while handling exists. Some foreign countries frown upon the use of Thoriated tungsten for its radioactivity. However, the risk does seem to be low as proven by many years of use in the industry. Overall, it probably offers the best performance for the price with a higher amp tolerance level for any given diameter.

Ceriated Tungsten (2%) has been recommended by major manufacturers of welding machines as an acceptable alternative to Thoriated tungsten for users of inverter welders. It has good low amp performance, with easy arc starts at low amp levels. However, the Orange tungsten is quite expensive compared to the Red. Some people swear by it and its performance. Others are not quite sure. Testing of Ceriated tungsten has shown that there may be some deficiency when compared to Lanthanated Tungsten. But there seems to be some strong opposition to that from people who regularly use Ceriated. Keep in mind it may be difficult to find at the local welding supply store. Many online sources have it so be sure to shop around as the price and quality varies greatly.

Lanthanated Tungsten is popular in 1.5% and 2%. Testing of both has shown that having more is not necessarily better. Lanthanated 1.5% is marked with a Gold paint, and Lanthanated 2% is marked with blue. Both have found considerable favor in the industry with many preferring the 2%. Many Everlast customers, who prefer not to use Thoriated tungsten have reported that this seems to work better for them than Ceriated. It seems to be found in more local locations than Ceriated. Price is slightly lower than ceriated overall.

Other types of tungsten are available, of course, and with the race to be newer and better, there have been unique blends with custom names t. Zirconiated has been promoted for AC use in transformer machines, but no real benefit is achieved for inverters. Custom tri blends have been recently promoted by a few companies, and sell at a premium price. However, they have not been around long enough to gain wide spread acceptance. Whether or not these actually provide a improvement remains to be seen, whether they perform all around better or not.

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GTAW Process: Personal Protective Equipment

Monday, September 19th, 2011

For the Beginner, TIG welding does offer an exciting and sometimes frustrating experience. It’s encouraging to know, that with practice and time, those first ugly, ropey welds, that resemble 4 day old road kill can be often be turned into nice, tight little stacks of dimes.

Getting a handle on TIG welding equipment and what is required to TIG weld properly helps to prepare the first timer to get up and running as quickly as possible. There are other items such as personal protective equipment, and welding accessories that must be purchased along with the welding machine to get safely started.

GTAW Process

GTAW Process

Of upmost importance, the newcomer will require substantial safety gear. A GOOD auto darkening helmet (also referred to as a “hood”) is the first requirement. Do not rely on cheap 2 sensor designs to TIG weld. A more expensive 2 sensor design can be used, but if a lot of low amp TIG welding will be done (below 30 amps or so) , a 3 or 4 sensor design will be required for maximum sensitivity. A good welding helmet will usually start around 175.00 and can exceed 700.00 dollars. Clarity is of concern as well. Don’t automatically go for the largest viewing area. Instead, look for clarity and quality over a “big” lens. Consider a quality pair of safety glasses as well. Some are available, that while clear, do offer protection from stray arc rays that tend to reflect off other objects in the area and make their way under the welding hood.

Gloves while important are more subjective. TIG gloves come in many styles, lengths and materials. Commonly, you’ll see goat skin and deer skin as a common leather component, to maximize sensitivity and flexibility. However, TIG can be a hot process and too thin of a glove can lead to serious burns. Don’t be tempted to leave off the gloves. Skin cancer is a real risk. The welding arc rays are more intense than the sun’s and can quickly cause painful sunburn, in a matter of minutes. A rule of thumb in considering a good TIG glove is that you can pick up a dime off a flat surface with the gloves on.

Another essential item for protection is a welding jacket, or at the very minimum, welding sleeves. Welding jackets come in a variety of styles: capes, jackets, lab coats, made from leather, fire resistant fabric, denim or any combination thereof. The idea is to provide the most protection with a level of comfort that safeguards the worker. Welding sleeves do provide a higher level of comfort and freedom of movement especially in hot areas, but may not offer adequate protection against stray rays that can penetrate thin shirts. If sleeves are to be worn, a minimum of a heavy denim shirt should be worn. Regular T-shirts and other shirts still transmit much of the harmful radiation.

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GTAW Process: Overview

Friday, September 16th, 2011

The Gas Tungsten Arc Welding (GTAW) process, commonly referred to as TIG, has long been considered a fine art form of welding. As a welding process, TIG welding, requires the most knowledge, practice, patience, and overall skill. Even many professional welders are reluctant to add the GTAW process to their welding repertoire due to the skill level and practice needed to thoroughly master.

GTAW Process

GTAW Process

Thanks to many of the reality fabrication and do-it-yourself shows and a sluggish economy, TIG welding has gained in popularity. A lot of people have suddenly found themselves edging toward owning their own business, whether it’s a motorcycle, rod shop, or even machine shop after watching non-stop marathons of their favorite fab show on the Discovery Channel or Speed Channel. One of the first purchases often sought is a TIG welder, as it seems to be the backbone of every DIY show on television, so naturally, it must be the backbone of the new shop. Right? Unfortunately, it’s also the very same purchase that brings the first dose true reality to newest Chopper shop to open its doors. It seems that TIG welding is not as easy to master as it seems. For some, the sheer cost of just getting started buying TIG welding related accessories blows the budget. The disappointment experienced by many not to be able to instantly weld is often a setback to getting the business going. Over the next few blogs, we’ll look at various aspects of TIG welding to offer some guidance and support to the person interested in making their first TIG welder purchase and getting their business off to a successful start.

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Ultra sonic welding

Friday, May 27th, 2011

This is a form of welding where the metals are joined without actually melting them. These are also known as solid state welding process. In this process, the metals to be welded are brought together under high pressure and strong vibrations are passed through the metals. Ultrasonic acoustic vibrations are applied to the metal locally which creates the weld between the two welds. This method is very effective in joining metals that are not similar. Also with the use of this method, there is no necessity of bolts, nails or adhesives necessary to hold the metal pieces together. A sonotrode is made use of in this form of welding. The sonotrode will apply the high frequency ultrasonic vibration that will cause the metal pieces to join together under high pressure. Due to the absorption of the vibrations, the thermoplast will melt locally causing a joining of the two metals. High pressure dispersion of the surface oxides can also be attributed to the joining of the metals.

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Choosing the right electrode for welding

Thursday, April 28th, 2011

There are many factors that you should consider before you choose the right electrode for welding. First you should consider the type of metals that are being used. You cannot universally use the same electrode for every metal you weld together.

What you use for aluminum and brass will not be the same as you use for steel. Next is the resistance to corrosion by the electrodes. This is an important property for the storage of electrodes. If you are buying electrodes in a bulk for the use of a long term project, you should defiantly keep this factor in mind. Next is the type of coatings that these electrodes would carry.

Electrodes may be consumable or non consumable. A consumable electrode may melt during the welding process and add to the strength of the weld. Therefore it would depend on the type of welding process you are using to join two metals.

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Methods to preserve electrodes

Monday, April 18th, 2011

There are many things that you should do for the preservation of electrodes. This is, to keep the electrodes safe until you use it again for the next project. The self preservation of electrodes depends upon the properties of the electrodes themselves.

One of the key elements here is that the electrodes that you purchase are meant to be kept dry. Humidity will lower the quality of the electrodes. Humidity will affect the quality of the coating which would in turn reduce the quality of the weld. There are special ovens available for preheating of the electrodes before they are put to use.

This pre heating is done to remove all moisture from the electrodes. With the removal of all traces of humidify from the electrodes, the welding procedure can be carried on successfully. Also these electrodes are kept in a moisture proof environment so that future damage can be avoided.

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An outline on Flux cored arc welding

Wednesday, April 13th, 2011

For flux cored arc welding, wire fed machines are used. The metals that are to be joined are melted first and then joined with the help of a consumable electrode that is continuously fed.

This process will require a constant voltage or a constant electric current. The flux core wire that is being used will also decide what type of external shielding gas is being used. This process is generally used for welding think sections and works great on welding oxidized materials.

The filler material for such welding process is usually costly. This is why it is not generally used for automotive works. This process is generally recommended for stainless steel and rusted materials. The advantage of this welding is the high speed of weld that it offers.

It can be used to get the job done quickly. Also portability is another asset of this kind of welding. This process is also very popular in constructions.

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Advanced TIG Technology is the way to go

Thursday, March 17th, 2011

Our world has evolved over the years. Man has adapted to every spheres of life and made the fullest of earth’s potentials. From cavemen to hunters, to inventors I can rightly say we have become technologists in today’s era. Innovation and creativity had been the only source of success and will be forever.

Birth of technology hasn’t made us stagnant. It itself has evolved from its initial stages and thus has revolutionized and modernized our ways of lifestyle. We are in the age where technology can behave like humans.

Has welding technology undergone enormous developments? Yes indeed. It is not so difficult to learn or handle anymore. Experience just produces better quality welds but even the inexperienced do undertake welding as part time jobs these days. The new TIG technology helps you to complete welding tasks faster, expend less effort, tackling bigger projects and allows you to do the same with lesser man power. It is quite expensive but manageable.

The newer technology tools are quite capable and reap several benefits when it comes to welding. Some of its core benefits are mentioned below;

• Superior arc and weld puddle in both AC as well as DC applications
• Faster travel speeds and greater productivity
• Superior weld quality and better bead appearance
• Optimizing bead profile
• Easier to learn and handle
• Smaller heat affected zone, reduced warping
• Low installation and operating costs
• Consistent welding

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Pulsed TIG for Stainless Steel

Wednesday, March 16th, 2011

Stainless steel has a low rate of thermal conductivity which causes the heat input to be localized. This localization of heating or cooling leads to distortion. The materials also undergo corrosion thanks to the localized excess heat. Experienced TIG welders know that stainless steel wraps if you do not weld it carefully with immense concentration.

Stainless steel comes in several grades for various different applications and while welding them most welders face common challenges. They are to minimize heat input while creating a good fusion between materials used and optimizing the bead profile. An expert welder can control the bead characteristics by adjusting the arc length, filler metal addition and amperage through remote control or manual control.

Pulsed TIG allows the welder to accomplish the following mentioned below which has revolutionized the art of welding and its output.

•    Increased narrow bead width to 52%
•    Increased penetration by 34%
•    Reduced the heat input 60% lesser than original
•    Increased welding speed by 35%
•    Produced better quality welds

The 300 series of stainless steel are the most popular for several pipe and tube manufacturing. It also accounts to about 70% of stainless steel applications. Pulsated TIG setup has mended the obstacles faced during welding the 300 series and provided the above results precisely and stood out brilliant when compared to the traditional welding techniques.

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