Welding Machine Buying Guide
Michael, Professional and passionate welder, Sheffield68 guides
- MIG MAG
Soldering Stations: MMA, MIG MAG and TIG
Are you restoring a car? Constructing wrought iron gratings? Building a trailer? Shoeing a horse or donkey? When working with wrought iron, stainless steel, or aluminum one of these welding methods should be suitable for your project.
Provided you use the appropriate welding station, you should have no trouble producing solid welding assemblies.
Today, trade welders have their pick from a range of dedicated soldering stations. Depending on your budget and the intended use, MMA, MIG, or TIG may be for you. Don’t forget all the safety equipment you’ll need to ensure the best results.
Welding machines: definitions and technical terms
Teaching yourself about the world of welding is a real trek into the unknown. To help you navigate along the way, here is a quick look at some commonly used terms.
Welding Machines: definitions and technical terms
The electric arc refers to the visible arc of electricity caused by bringing the electrode in contact with the metal ground – it looks like a flash of lightning!
Priming is first step in the welding process and really only refers to running the electrode over the metal you are going to be welding.
Rutile Electrode or Welding Rod
The rutile electrode is the most common and most widely used. Its coating is conductive, which facilitates the initiation and fluidity of the weld. Melting the coating forms the slag which protects the weld from oxidation and is easily removed with a hammer.
The basic electrode is mainly used industrially for pipe fitting and boiler work. More expensive and harder to prime, the basic electrodes require preheating before use.
This wire contains a core of flux (the same as the coating) which helps the metal melt without forming pockets of air.
Braided or Solid Wire
Copper-plated steel wire or plain stainless steel, braided or solid wire both allow for welding with a supply of either inert or active gas (MIG or MAG).
The connectors are plugs for connecting the ground and clamp cables to the welding assembly.
The clamp is a handle that connects the coated electrode in MMA welding.
The MIG-MAG torch is a handle with a trigger to bring the wire to the welding metal.
The TIG torch is a tungsten electrode handle that houses the controls.
The gas helps protect the weld against oxidation in the open air. It is often argon or an argon-carbon dioxide mixture.
A valve used in TIG or MIG-MAG. The solenoid valve allows the welder to control the gas being fed to the torch.
Another type of non-tungsten electrode.
Double pressure regulators pressurize the gas being fed to the torch and control its outlet (measured in liters/minute) with an adjustable wheel.
Description of a welding machine
Basically, a soldering station is a sophisticated transformer that converts your 220V Alternating Current (AC) to Direct Current (DC) at varying amperes depending on what intensity you need.
A potentiometer makes it possible to refine the adjustment (or to vary the amperage).
They often have two positive and negative pole connectors :
- One for the electrode holder
- One for the ground.
Which welding machine for which welding task?
Before embarking on the specifics of each welding project, here’s a quick look at welding machines.
The MMA Inverter is great for beginners. Why? The post is lightweight, you can weld metals with thicknesses from 2 to 10 mm with ease. The power demand from the station is relative to the thickness of the metal to be welded. So if, for example, the power on your station is set too high, you will make holes in your support due to too much fusion. On the other hand, if you do not have enough power, your wand will just stick to the backing.
The best inverter technology? Look for combination of features, comfort of use, economy of electricity, ease of welding. A single knob potentiometer allows you to adjust the power according to the thickness of the metal you’re going to weld. It shouldn’t flash too much, it shouldn’t stick, it just welds.
Semiautomatic welding allows a higher welding rate thanks to its continuous cored wire.
Unlike MMA, the weld does not require you to remove slag once the weld cools.
MIG MAGMIG MAG, solid wire with gas, is the preferred method for large-scale welding projects.
However, it can also be used with very fine wire for making very thin or fine welds that can be ground and polished until their nearly invisible, making it great for coachwork. These machines lend themselves to a wide range of uses.
TIG welders use thin sheets of carbon steel and stainless steel as well as stainless steel tubes or fine tubes.
The quality of welding is remarkable for its fineness and appearance.
Soldering Stations: characteristics and advice
- Use – what you intend to make with it along with the type of thickness of the metals to be welded
- Operating factors - expressed as a percentage at a given amperage – for example: 70% duty cycle at 100 A which corresponds to 7 minutes of welding and 3 minutes of cooling for every 10 min of use. This factor is "inversely proportional" to the intensity chosen, which means the higher the intensity, the longer the cooldown time.
- Welding quality - this is determined by the performance of the station, the combination of the correct welding parameters, the quality of the electrodes, the wire or the filler metal, and of course your dexterity.
- Frequency of use - as with other equipment, you will find models for occasional, regular, or frequent use as well as for the novice, intermediate, or expert welder. The price will likely correspond with how high on these scales you fall.
- The power – a mid-range machine, from 40 A to 130 A, for electrodes from 1.5 mm to 3.2 mm is an investment that will protect you from potential problems. No need to weld with 4 mm, two passes of welds in 3.2 mm do the trick.
MMA (Manual Metal Arc) Inverter: welding machine for starters
We have all used the big, heavy, red or blue posts. There’s no need to haul around all that dead weight. Heavy duty welding stations with delicate priming are still available at the entry level.
If you are starting out, go directly to the MMA Inverter. The new generation of these posts are in a class all to themselves.
How an MMA works
Presentation side - A switch, a potentiometer, and two connectors, one for the clamp and the other for the coated electrode holder (the electrode can be either rutile or basic depending on the nature of the metal to be welded).
On the practical side - At ignition, an electric arc gives the heat source (± 3600 °) necessary for the simultaneous melting of the electrode and the metal seam. Then hold it there, do not shake, maintain contact until this fusion is complete and then observe the result.
It is important to heed the advice you get from professionals and do-it-yourselfers, but it is especially important to train on metal scraps. With a little patience, you will soon master the technique and the intensity settings. Today’s machines promote adaptation to differing welding practices. Take a few notes to remember the parameters you used on specific projects and the result you obtained.
Also, since the station operates in direct current, the positive polarity is preferable for the electrode holder. The result: better stability, good penetration, and fewer projections.
Another point, any welding brings about some deformation due to heat. After cooling the weld can sometimes become a little wonky. To make up for this, the weld can be pounded out a little to lengthen the metal so that it returns to its shape. Clamping your work down to a workbench is another good solution.
Semi-automatic Welding: the welding process
A method of welding controlled at the torch and comprising an electric arc which causes a filer metal to melt. The welding wire contains a core of flux which regulates its fusion during welding and does not require the use of gas. The fusion of the wire that replaces the electrode allows the assembly of the metal parts.
The penetration (depth of fusion) depends on the running speed and the selected amperage.
The torch can be pushed for greater penetration or pulled for a finer cord). It should be positioned very close to the metal.
There are coils of cored wire with a diameter of 0.8 mm (sometimes 0.6 mm) up to a maximum diameter of 3.2 mm for professional workstations.
Often the stations are pre-equipped for MIG MAG welding.
The criteria for choosing are determined by your welding project:
- The voltage you have (220v single-phase or 380v three-phase)
- The intensity in amperes in relation to the thicknesses to be welded
- The diameter capacity of the wire and the storage of the coil
- The quality of the rollers of the reel (important for unwinding the wire)
- Pre-equipment MIG / MAG option (gas torch power supply)
MIG MAG Welding: for what use?
A quick reminder of what these acronyms mean:
MIG: Metal Inert Gas
MAG: Metal Active Gas
Semiautomatic welding using braided or solid wire coils. The principle is the same as with the cored wire except that an inert or active gas is diffused at the weld point by the torch instead of using flux. This gas protects the weld from corrosion, provides the stability of the arc, and improves the appearance of the weld. Depending on the choice of gas, steel and stainless steel can both be welded.
MIG MAG Welding: the definition and difference
MIG welding requires an inert gas (Argon) for the welding of light alloys, stainless steel, or copper.
MAG welding requires an active gas (Argon/Carbon Dioxide mixture) for the welding of carbon steels.
These pressurized gases are stored either in separate disposable cartridges for small volumes (1.8 liters to 3 liters) or in refillable bottles for large volumes (130 liters to 10 m 3 ). A flow/liter regulator fixed on the bottle regulates the gas flow.
In both processes, gas consumption is expressed in liters/minute.
This flow is inherent in the size of the nozzles of the torch. By estimating the welding time and the flow adjustment, it is possible to calculate the gas requirement and thus determine whether you need to purchase a cartridge or a bottle. The gas keeps for a long time, do not forget to close the inlet valve after use. Advice that’s reinforced by the wallet.
TIG, Tungsten Inert Gas: the rolls of welds
TIG welding (manual) is a form derived from electric arc welding. A neutral gas is diffused by a ceramic torch comprising a non-fusible tungsten refractory electrode (needle). This method makes it possible to obtain a very high-quality weld.
Use of TIG welding
Depending on the dexterity of the welder, the melt can be worked for a larger weld or very thin welds. Its use is particularly recommended for hyper-tight welds, for high pressure or piping and even for nuclear. TIG can be used for metals such as iron but is recommended for non-ferrous metals such as titanium and aluminum.
The tungsten electrode must never be in contact with the workpiece; The welder must both control the energy input of the torch and the deposit of filler metal (not coated). The weld bead is protected by the neutral gas to prevent corrosion of the welded metal. the heating zone is restricted, which considerably reduces the thermal deformation caused by welding, unlike flame welding. This process produces little smoke and provides exceptional weld precision.
TIG Welding Stations: the basic description
The welding station is generally mixed, MMA Inverter welding and TIG welding. A switch selects the welding mode, then just make sure that your welding technique matches the mode you have selected. Negative torch polarity is imperative for TIG welding. The inert gas intended for the torch passes through a solenoid valve controlled from the torch. Entry-level welding stations are equipped for high frequency which allows for starting without the tungsten electrode coming into contact with the metal. Thus, the needles are saved, which is not a negligible concern as far as your wallet is concerned. Potentiometers are used to regulate the supply of gas with a delay before and after welding (pre-gas and post-gas).
Advice: When welding, both hands are occupied. Make sure you wear face protection, a welder’s hood is preferable, not to mention soft gloves to protect your hands and an apron or leather jacket to avoid burning yourself and punching holes in your clothes.
Additional information on welding machines can be found below:
- How to choose your soldering iron
- How to choose your protective gloves
- How to choose your flame welder accessories
- How to choose your welding mask and protection
- How to choose your flame welder
- How to choose your Arc welding electrodes
- How to choose your gas cylinders for flame welding
- How to choose your welding tools and protection
Michael, Professional and passionate welder, Sheffield 68 guides écrits
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