TIG welding machine
The term “welding” refers to a process that connects components inseparably by means of pressure and/or heat, either with or without filler material. Auxiliary materials such as pastes, shielding gases or welding flux facilitate the welding process or make it possible in the first place. Welding requires not only experience and appropriate knowledge, but also a certain amount of equipment. The effort is worthwhile, because extremely precise weld seams can be drawn by welding with gas. The gas protects against unwanted chemical reactions. One method of welding is the gas-protected tungsten inert gas welding, the so-called TIG welding. Special TIG welding machines have been developed for this purpose.
What is a TIG welder?
TIG welding is one of the welding processes with shielding gas and is particularly precise and complex. In the middle of a tungsten electrode, which cannot melt away, and the work piece burns an arc. The melting pool, the electrode and the arc are protected from the atmosphere by using an inert gas. If a filler metal is required, it is supplied as a cold wire, melted in the arc before the molten pool.
How does a TIG welding machine work?
The TIG welding process is a slow variant and the molten pool contains only a small area. Similar to writing, the electrode is guided over the workpiece one after the other and from left to right. Contact is made by the arc. In the beginning the molten pool develops underneath the arc. As the electrode continues, new material melts, while the previous molten material slowly solidifies again. The molten pool can be divided into three areas.
The area on the right is the area that is just starting to melt, the area in the middle is the liquid and the area on the left is the section that is just starting to harden again. The addition of the melting additive is more to the right and in the middle. This ensures enough time for the additive to melt, bond with the material in the middle and finally harden into a material.
Possible applications and for whom the WIG welding machine is suitable
Compared to the other welding methods, the TIG welding process has considerable advantages, but it is not suitable for exclusive use in the hobby sector. The TIG welding process is always used when high quality demands are placed on the weld seams. It is unsuitable when it is purely a question of speed. TIG welding includes the following features:
- non-melting tungsten electrodes are used for the TIG welding process. Unlike, for example, electrofusion welding, the electrode does not have to be changed constantly. Due to the use of these non-melting electrodes, there is no direct connection to the electrical circuit in the TIG welding process. The current intensity can therefore be controlled at will and adapted to the material. In contrast to other welding variants, almost no welding spatter is produced here. Furthermore, no slag that could lead to slag inclusions develops.unlike with electric welding, only a small amount of smoke develops, so that the welder is not exposed to toxic fumes and smoke.the inert gas acts in the welding zone and in the arc as a protection against the surrounding atmosphere, whereby a chemical reaction by the surrounding air and the material can be excluded.
In the past, TIG welding was almost exclusively used in industry. The TIG welding equipment was extremely expensive and therefore rarely found in a private household. In the meantime, however, they have become more common in domestic use. Although the prices for TIG welding equipment have fallen, TIG welding still involves a high level of additional expenditure. Firstly, shielding gas must be added and secondly, a separate filler metal is required. For these reasons, TIG welding is still one of the processes that is mainly used by professional welders.
What can be welded with a TIG welding machine?
TIG welding machines can be used in many different ways. For example, the TIG welding process is used in the aircraft industry and also in the aerospace industry. It is also used in pipeline construction, railing and steel construction and in ventilation and heating construction. In principle, it can be said that the TIG process can be used for automated and manual welding. A further special feature is that TIG welding can be used to process special materials such as titanium and extremely thin materials.
TIG welding in general has various special features compared to the other welding methods. One already mentioned special feature is the non-consumable electrode. Furthermore, both direct and alternating current can be used here. Many other welding methods only work with direct current. In practice, however, the majority of materials are welded using direct current. The torch is connected to the negative pole, which is not quite as hot, and the elementary thing is that the components to be used, such as the filler material, the shielding gas and the ground joint of the tungsten needle, are optimally matched to the weld piece.
Within TIG welding, the arc can be created in two different ways. Either the arc is generated by means of a contact-free high-frequency ignition or by a contact ignition. How the ignition takes place depends on the welding machine and its equipment. If there is a high-frequency ignition on the equipment, it should always be used.
In general, TIG welding is a complex and extremely demanding welding process and is similar to autogenous welding. During the welding process, the welding wire is guided with one hand and the torch with the tungsten needle with the other. The speed of welding is also similar to that of oxyacetylene welding, but much slower than MAG welding, for example.
- Filler metal can be freely selectedExact control of the filler metalFew toxic fumes and weld spatterExtremely high quality welds
- Comparatively much more time required
Who can repair a TIG welding machine?
If one or more defects occur on a TIG welding machine, it is advisable to leave the machine to a specialist. It is not advisable to carry out repairs independently and alone. Due to its complexity, it requires a specialist who is familiar with the relevant technology. There are also numerous providers on the Internet who offer repair of TIG welding equipment. In addition, the warranty (if still available) expires in case of unauthorized interference.
Care and cleaning
Under normal working conditions, TIG welding machines generally require little maintenance and only a minimum of care. Cleaning work is only carried out when the unit is disconnected from the power supply, otherwise considerable injuries may occur. The mains plug must be disconnected and then you should wait at least 4 minutes to allow the capacitors to discharge.
The 5 major manufacturers and their characteristics
- One of the largest manufacturers in the field of TIG welding equipment is the company REHM. The producer offers TIG welding machines with direct current, as well as with direct and alternating current. These are available in portable and/or mobile versions. They are cooled either by water or by gas, another well-known producer is the company Jäckle. The program includes transistor controlled direct current systems as well as mobile and portable inverter power sources. The welding machines are equipped with high performance ignition devices for a reliable ignition of the arc. The manufacturer Jäckle has installed a remote control socket in the welding units as standard. The company GYS. is also an international leader in the field of welding technology. The manufacturer is highly specialised in the serial production of welding machines which are inverter-based, but also in conventional welding machines. GYS employs more than 40 engineers in research and development alone, and GUEDE is a supplier of tools and machines. The product range therefore also includes various TIG welding machines and the company Schweißkraft is one of the leading manufacturers on the market. Schweißkraft has a wide range of products in the field of TIG welding equipment. In terms of price, a TIG welder can be bought for under 100 usd, while the price can be as high as thousands.
Equipment for the TIG welding process
Before you can work with a TIG welding machine, a few things must be considered. First of all, the material to be welded must be considered. If, for example, non-ferrous metals or alloyed steels are to be used, it is best to use TIG welding machines that are designed for DC welding. Light metals, on the other hand, are preferably processed with welding equipment for alternating current welding. So-called combination devices are available, however, where you can switch from direct current to alternating current at the touch of a button. A mobile regulator is also required to regulate the current intensity continuously.
The welding current line, the control line and, in the case of large torches, the return and inlet for the cooling water and the shielding gas supply are located within the hose package. The electrode is selected according to the nature of the material to be welded. The electrodes are identified by the colours gold, red, purple, green and grey. The diameter of the electrodes ranges from 1.6 mm to 9 mm. Which electrode is intended for which application can be found in the instructions or a corresponding table.
Accessories for TIG welding machines
For the TIG welding process there is a wide range of accessories available in addition to the actual welding equipment. For example, a foot pedal can be purchased separately, as well as a water cooler for hose packages, automatic helmets, a torch holder, pressure regulator and clamping sleeves. In addition, for TIG welding you need a grinding block with a stainless steel grinding wheel so that the tungsten electrode can be sharpened.
What to look out for when buying?
If you are interested in a TIG welding machine, you should consider important things when buying it. First and foremost it is important to think about what you want to weld. With TIG DC units, all high-alloy steels, tool steels, steels, brass, copper and stainless steels can be welded. With TIG AC/DC units, magnesium alloys, aluminium alloys and aluminium can also be welded. There are also different TIG welding machines.
The cheaper devices have only one ignition, which is contact-controlled, i.e. the tungsten electrode must always be placed on the material first and then lifted to ignite the arc. This increases the wear and tear of the electrode. Slightly better devices have a high-frequency ignition. This means that the arc is ignited above the workpiece by means of a high-frequency ignition unit.
There are also welding units with a gas post-flow time to be set, a pulse function and a current rise and fall time. These are particularly suitable when thin pipes or sheets are to be welded, as the debris flow can be freely selected. In other words, the plate does not burn away at the beginning of the weld seam and at the end. Furthermore, it is decisive which thicknesses are to be processed, with regard to the thickness of the sheets and the pipes.
5 good reasons for TIG welding machines
- TIG welding belongs to the fusion welding process and is universally applicable. It is mainly characterised by its clean and precise processing. There are almost no spatters and gases are hardly developed at all. This has enormous health benefits for the welder: the current required to process the workpiece is supplied by the tungsten electrode and that electrode does not melt like others in MAG and MIG welding.During TIG welding, the quantity of filler metal and the required current can be adjusted by the welder himself, the filler metal is fed in continuously or drop by drop and the welding wire is always in the liquid weld pool. For this reason, the welding process is also known as the stabbing method.