Posts Tagged ‘Welders’
Friday, March 30th, 2012
On the underside of any plasma cut, small amounts of slag may collect along the sides of the cut. This dross can be significant or minimal. It can be hard to remove, or easy to remove. If it is significant, and hard to remove, and you notice that the cut line angle dramatically increases toward the rear of the weld, it is a good sign that the maximum cut capacity of the plasma cutter is near or the maximum cut for the set amperage has been achieved. If it is significant and hard to remove, but cut lines are normal, air pressure may be low. If the dross is significant and hard to remove, and the cut lines are irregular, then cut speed may be too fast. If dross is irregular, then cut speed may be varying, or torch height may be changing. If needed use a cut guide, or a standoff to keep a consistent cut height. Be careful also to watch for discoloring of the cut or sootiness, of the consumable, if any negative cut condition occurs. This may be an indication of moisture in the lines. Ideally, the cut should have less than 1/8” of dross on the cut backside, and cut lines are angled at a 30-40 degree angle toward the rear of the cut if all things are working as they should. Melting back over of the dross or closing up of the cut can indicate too slow of movement, or too low of air pressure or too high of amperage for the thickness. Loss of cut can indicate too fast of travel speeds as well.
Tags: Arc Welder, MIG Welder, plasma cutter, TIG Welder, Welders, Welding Equipments, Welding forum, Welding lease
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Wednesday, March 28th, 2012
As much of a factor as the pilot arc duty time is in determining overall consumable life, proper torch manipulation is just as important, for both consumable life, and cleanliness of the cut. As already mentioned, having the torch close to the metal, ready to cut when the torch trigger is pulled is important. But also important, is starting the cut at or near the edge of a piece of metal when possible. If a part is drawn out or a template is used, the part to be cut should be placed on the metal to with at least one side near the edge or corner of the material. This will allow the torch arc to start just off the side of the metal, and the torch to be moved quickly into the full cut. This will allow a short “lead in” for the cut, so that little metal is wasted, and starts can be started, without the flame needing to cut through the entire length of metal first before starting the cut. Starting the torch in the middle of an intricate design, or cutting a hole in an object, will require a technique known as piercing. Piercing involves a steady hand and some for thought. Vertical piercing, where the torch is held 90 degrees over the cut, is the quickest way to destroying consumables and even the torch, especially on thick materials. CNC use cutters do in fact use this technique, but in reality, the capacity of a plasma cutter when used with a CNC table is cut in half because of this. Blowback from the spark and flame when the cut is started from straight overhead is redirected right back into the face of the consumable and torch. This blowback sends hot sparks, flame and material the wrong direction! For best use when piercing, identify the discard side of the cut. Angle the torch head back 30 degrees or so with the nozzle pointed toward the discard side cut, then start the arc. Rotate the torch head vertical as the arc begins to penetrate, and begin cutting. This will allow the arc to bounce the blowback away from the consumable face. Keep in mind the arc should be directed to the discarded side of the cut or you will cause damage to the piece you are trying to keep. This is a fairly rapid motion. If it takes too long to pierce, you may have reached the practical limit for piercing. The practical piercing capability of almost any plasma cutter is limited roughly to ½ it’s maximum clean cut capability.
Tags: Arc Welder, MIG Welder, plasma cutter, TIG Welder, Welders, Welding forum, Welding lease
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Monday, March 26th, 2012
Once you have figured out how to set the welder’s amps and adjust the air pressure to achieve optimal cuts, developing the correct technique is the next hurdle. Over the course of many conversations with customers, I have found a common concern of customers is the expense and lifespan of consumables. The consumable life span is no better than the way it is treated, and used. One reason we have added an adjustable post flow time to our Everlast plasma cutters is to help increase life span of both the torch and the consumable. Post flow cooling is critical to maximizing consumable life. About 1-2 seconds of post flow per 10 amps is a good starting point. The longer the cut, the more the post flow cooling is required as well. One frequent mistake is that customers frequently like to see the torch flame and over-exercise the pilot arc function. To create a pilot arc, a lower amp current is sent out, and the arc is created and maintained through a grounded circuit within the torch itself. This means the arc is being produced and borne on the surface of the consumable! This alone counts for the bulk of consumable wear. When starting a cut, the pilot arc is only held on for a fraction of a second normally. This is fine. But starting the arc in the air, then putting the arc close to the metal to begin cutting, similar to an oxy acetylene setup is a no-no. Repeatedly giving the pilot arc quick short bursts by test firing it in the air is just as bad. When setting up the cut, position the metal so that once the pilot arc starts the cut can be initiated immediately. This will keep pilot arc time to a minimum. Cutting rusty/painted metal or expanded metal grating will inevitably increase the pilot arc duty, but it is something that cannot be avoided. In these cases, expect for consumable wear to increase.
Tags: Arc Welder, MIG Welder, plasma cutter, TIG Welder, Welders, Welding forum, welding helmets, Welding lease, welding machine
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Friday, March 23rd, 2012
A number one question I often get is “What’s the thinnest material this metal can cut?” That of course to an experienced user of a plasma cutter is a relative question. In reality, any plasma cutter really has no bottom, or minimum thickness that it can cut. It’s sort of like trying to define what the smallest fire a single match can set would be. In other words, every plasma cutter can cut through the thinnest metal sheet you could find. Not all would do it as well, though based off of the tip design and diamerter of the orifice in the tip. Some would leave a broader, wider kerf, others would look like a razor blade made the cut. It would depend upon the amperage used as well. Amperage control is key to giving the best quality cut on any given thickness of metal. But, at a point lowering the amperage, makes no economical or practical sense. Speed and quality have to be balanced. As amps are lowered, quality can go up, but speed can drop drastically. And at a certain point, quality begins to quickly drop when amps are lowered too far. There is a rule of thumb that I have come up with when using a plasma cutter to achieve the best cut. You won’t find it in any plasma cutting manuals though. I have found that 20 amps is truly the lowest practical limit for a plasma cutter. That amperage is good up to 1/8” of an inch. After 1/8” you can typically add 10 amps for every additional 1/8” of cut. While this isn’t perfect for all conditions, it works well as a general guide. For 3/8” cut, 40 amps works out well for most brands of plasma cutters. For ½” cut, 50 amps works out well, etc. Keep in mind this isn’t the maximum thickness of cut that a plasma cutter is capable of cutting but rather, it is a good rule to follow for decent cutting speed and quality. For most torches, various tip sizes are available, each with its optimum cut range.
Tags: Arc Welder, MIG Welder, plasma cutter, TIG Welder, Welders, Welding forum, Welding lease
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Wednesday, March 21st, 2012
By now, if you’ve gotten your plasma set up and a dryer installed, you’re likely wondering exactly how much air pressure to use, and what amperage to set for each thickness. You may even be surfing around the net for some chart to give you a precise setting of amps and air pressure with a cross reference for each possible variable and situation. The bonus and hidden feature of plasma cutting, is that close is usually good enough to get the job done, and done well. It’s really difficult to give real details on dialing in a plasma cutter. Sure, a plasma cutter designer could go through several detailed and laborious design parameters, and projected performance for each rough setting, but it will never substitute for user practice, and hands on experience. In short, experience is the best teacher. With the Everlast Power Plasma series plasma cutters, the units have a signal light that tells the operator when air pressure is past the safe minimum range, above 35 psi roughly. This does not mean though it is at optimal operating pressure when the light comes on, but at a pressure that will help protect the torch from meltdown. It also has built in over current and duty cycle protection that will shut down operation should something be done seriously wrong with the unit. This helps take a load off the user at the beginning. One thing concerning basic air pressure settings, across the board, with each manufacturer and torch, air pressure requirements and flow requirements can greatly vary. For the majority of the Everlast product line, air pressure required to operate the torches is anywhere between 55 to 70 psi. Low amperage cuts will require less air pressure for more stable operation, sometimes down to 45 psi or so, or the arc will be blown out. In general, the blowback design torch found on the PowerPlasma 50 works best around 60-65 psi for most pressures. The HF torches can vary more, but simple, short test cuts can give great insight on the optimum pressure. Look for signs such as dross (slag) residual, cleaness of cut lines, and kerf width to help you find the best pressure for the amp level and material you are cutting.
Tags: Arc Welder, MIG Welder, plasma cutter, power plasma, TIG Welder, Welders, Welding forum
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Monday, March 19th, 2012
One of the most easy to use tools today in the welding industry is the portable plasma cutter. It is been used extensively recent days to cut steel along with several other electric current conductive metals because of their portability facilitated by inverter technology. Several companies are getting benefitted by plasma cutting process for it lowers the costs and increases the productivity rapidly. With the advent in technology, portable plasma cutters are better serving the industry. When it comes to handheld plasma cutter all that must be kept in mind is the thickness of the metal you will be cutting usually and the thickest metal you will ever cut, and how fast you want to cut.
These portable plasma cutters function by using a real high voltage electrical arc along with a compresses gas, which is usually air. The electrical arc is generated by an internal electrode which ionizes the gas passed through a nozzle; thereby creating a concentrated arc of plasma right at the portable plasma cutter’s tip. When the electric arc is contacted with the metal works it results in a circuit with severe high heat which then melts the section of less than 1.6 millimeter broad.
Tags: Arc Welder, MIG Welder, plasma cutter, TIG Welder, Welders, Welding forum
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Friday, March 16th, 2012
Tungsten inert gas (tig) is often used for high-quality precision welding purposes. In this particular process an arc is formed between the metal and the permanent non-melting tungsten electrode. With the help of the torch the gas is fed, thereby it shields the electrode and molten weld pool. In case of usage of filler material, they are added discretely to the weld pool.
There are several benefits of tig welding and it takes into consideration finer quality welds, clear-cut control of welding variables such as heat, independence of spatters and low warp. Moreover, it can be used at lower amperages for thinner metals and they can be used on exotic metals.
It can be used on different types of metals, but most commonly aluminum is used in particular metals of a smaller thickness.
Almost all types of metals can be tig welded but the most recurrent metal that is associated with this type of welding process is the aluminum, predominantly smaller thickness metals. Even though there are several other set of processes that allows joining aluminum, tig is one such process that is most applicable in the case of lighter gauges.
On the whole, as a rule, the gas tungsten arc welding process is best for repairing aluminum.
Tags: Aluminum Welding, Arc Welder, MIG Welder, plasma cutter, stick welding, TIG Welder, tungsten, Welders
Posted in Tig Welding | No Comments »
Wednesday, March 14th, 2012
Spot welding is a great form of resistance welding, which is a technique of welding two or more metal sheets jointly without by means of any filler material by pertaining pressure and heat to the area to be welded.
Spot welding is one such technique that is usually used to bond metals shaped into sheets that is not thicker than 3 millimeters. Just like any other welding technique even spot welding can produce clear-cut bonds without making excessive heating that can have an effect on the properties of the leftover sheets. This is pulled off by setting free a huge amount of energy in a short time in order to produce restricted and consistent welds. When it comes to galvanized steel then higher levels of current is required.
Tags: Arc Welder, MIG Welder, plasma cutter, spot welding, TIG Welder, Welders, Welding Equipments, welding machines
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Monday, March 12th, 2012
A more modern approach to starting an arc is the use of “blow back” technology. This technology uses a dead short where a spring loaded electrode is firmly seated against the nozzle face and air pressure is applied to the torch. The air pressure pushes the electrode back so the air can escape from the nozzle hole. Simultaneously, electricity begins to flow creating a spark between the nozzle which is grounded back through the machine to complete the circuit, and the electrode. This ionizes the air, and a low amperage plasma arc is established. This design automatically includes a pilot arc. It cannot work unless there is a complete circuite within the torch head. This start type poses no threat to surrounding electronics, or to the machine itself. It can be a little slower start than the HF style, but most people see little or no difference. Some disadvantage exists in the fact that occasionally the arc won’t start, but usually only in very rare cases. Most major companies utilize this style start under 100 amps. The inherent design creates problems for use in plasma cutters greater than 100 amps, however. An advantage of this design is that there are no high frequency points to maintain, and the start style is very friendly and can be used in sensitive areas. Most people after using both blow back and High Frequency start styles, find little practical difference in regular cutting. However, regardless of the start style, the pilot arc is usually the thing that most people feel they cannot live without. A blowback torch consists of moving parts, but usually, life span is nearly that of a High Frequency torch. But it is usually considerably more expensive for the blowback torch than a High Frequency torch, should one need to be replaced. The Blowback style does typically have more parts, and is more sensitive to any small variation in improperly set parameters, especially air pressure.
Tags: Arc Welder, Blow back, MIG Welder, plasma cutter, TIG Welder, Welders, Welding forum, Welding lease, welding machine
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Friday, March 9th, 2012
There are two common start types that you should be familiar with. One is High Frequency, and the other is a Blow back start. The High frequency start is a simple, but effective method of starting that uses something similar to old fashioned ignition systems of automobiles with a coil, and points to generate a high frequency, high voltage spark at the tip of the nozzle to ionize the air and create a plasma arc that is focused and expelled through the tip of the nozzle. This type of start is efficient and fast but has two basic problems. The first is that it creates a lot of electromagnetic interference and is not suitable for use around computers, and electronic devices. The HF energy can create isolated and sometimes mysterious problems, which are hard to pinpoint and predict in surrounding electronic equipment. Also due to the design of the HF, some systems do not provide a pilot arc. Pilot arcs provide a plasma arc that is self contained without the benefit of a complete grounded circuit that routes power flow back through the work lead. Instead, the torch provides its own ground, and the arc is created against the consumables as a grounded point. The design of this pilot arc provides a softer, non cutting flame at reduced amperage to provide a steady arc that helps scour and prep the surface for full arc transfer. It makes cutting on irregular surfaces such as expanded metal, and on rusty or dirty metal a very easy task. No arc restarting is required, and continuous transfer back and forth of the pilot arc when needed is accomplished. The reduced amps are used in order to keep from blowing out consumables rapidly. In an HF system, the arc is started usually by having the torch in close proximity, if not touching the workpiece. Some HF systems do provide a grounded consumable, to create a pilot arc. These units can work quite well for a variety of applications, except for machine or cnc use.
Tags: Arc Welder, high frequency, MIG Welder, plasma cutter, TIG Welder, Welders, Welding forum, Welding lease, welding machine
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