Welders are indispensable pieces of equipment for a car repair centre. These hard-working machines have the ability to melt and fuse metal in a strong, durable bond. However, given the range of options on the market, it can be difficult to pin down a cost-efficient welder. Buyers need to keep in mind that cost effectiveness is comprised of a number of factors. The least expensive model may not always be the most cost-effective; therefore, car repair specialists should take several things into consideration.
First, it is vital to find the right welder for the job. Different types of equipment are more suited to certain tasks, so familiarity with the selection of welders available is vital. Next, buyers should carefully consider power specifications, including output, input, and duty cycle. These need to be weighed against the job requirements, as well as the power supply available in the repair centre. Other less obvious factors also come into the equation, including ease of use, operator training requirements, and repair availability.
These considerations can help buyers find a quality, cost-effective welder for their business.
Types of Welding Used for Automotive Repair
There are several different types of welding, but for car repair the most common type is arc welding. The basic principle in arc welding is to create and sustain an electric current between an electrode and the base material to be welded. The heat from this current melts the metal at the point to be welded, and once the heat is removed and the materials begin to cool, the pieces are fused together. Sometimes an inert or semi-inert gas called a shielding gas is used to protect the welding area from atmospheric contamination. In addition, filler material may be used to act as a bonding agent between the parts. The types of arc welding commonly used for car repair are gas metal arc welding, also known as MIG, shield metal arc welding, and gas tungsten arc welding, also known as TIG.
Resistance welding is used at times, in the form of spot welding. With resistance welding, an electric current is passed through two or more layers of metal. The resulting resistance generates heat, which melts the metal.
Gas Metal Arc Welding, or MIG Welding
Gas metal arc welding, or MIG (metal inert gas) welding as it is commonly known, emerged in the 1940s and remains one of the primary forms of welding for both home and industry. MIG welding involves the creation of a continuous short circuit between an anode, the positively-charged welder, and a cathode, the metal to be welded. It employs a consumable wire electrode, wrapped around a spool and continuously fed through a rod. As a result of the heat generated by the arc, the wire melts and joins the base, where it acts as a filler material. An inert or semi-inert gas surrounds the wire to shield the weld area from contamination.
Flux-cored arc welding (FCAW) is a variation on MIG welding in which the wire contains powdered flux materials that generate a shield for the welded area, thus eliminating the need for an external supply of shielding gas. The result is a more portable welder that can be used in a variety of outdoor conditions.
MIG welding has several advantages. It works on many types of metal and from a variety of positions; in addition, it produces a good weld bead, and has minimal splatter.
The potential disadvantage of a MIG welder is that it can only be used on metal of thin-to-medium thickness, meaning that it may not work for all industrial jobs. However, it should be sufficient for most car repair.
Buyers should be aware that MIG welding is, technically speaking, now referred to as Gas Metal Arc Welding (GMAW). However, the term MIG welding seems fairly entrenched, and appears to still be very much in use.
Shield Metal Arc Welding (SMAW)
Shield metal arc welding, commonly known as stick welding or manual metal arc welding (MMAW), is a popular method that has low equipment costs, requires little operator training, and is quite versatile and robust. With shield metal arc welding, the arc is formed between the metal being welded and a consumable electrode rod or stick covered by flux. The electrode core acts as filler, and the welded area is protected from atmospheric contamination by the vapors and slag the flux produces.
While this method is best with ferrous substances, specialised electrode rods have made it possible to use shield metal arc welding with copper, aluminum, and nickel. Disadvantages of shield metal arc welding include that it can be time-consuming, as the electrode must be regularly replaced, and the slag needs to be chipped away after welding.
Gas Tungsten Arc Welding (GTAW) or TIG Welders
TIG (tungsten/inert-gas) welders produce an arc between their non-consumable tungsten electrode and the metal to be welded. Their operation requires a high level of skill, a high-frequency generator, and is a time-consuming process, which is why it is often applied when the quality of the weld is of utmost importance. TIG welders can be used on a wide range of welding metals, and are particularly useful for thin materials.
Spot welders differ from MIG, stick, and TIG welders in that they are resistance welders. Spot welding clamps two electrodes around the metal to be welded and runs current through the metal; the resistance then produces heat, which in turn melts the metal. Spot welders are generally energy efficient, easy to operate, require no filler materials, and have a minimal cosmetic effect on the material. However, the strength of the weld is not as high as with other types of welding, and the equipment can be costly.
Considering Which Type of Welding is Needed
As discussed above, different welders are better suited for certain jobs. It helps to think in advance about the types of base materials buyers expect to work with, as well as the thickness. Automotive repairs generally deal with medium-to-thin pieces, 0.48-cm thick or less. As for materials, the following chart reviews which welding types are most recommended for certain metals.
MIG, stick, TIG
MIG, stick, TIG
Exotic Metals (e.g., Magnesium, Titanium, etc.)
This information should help car repair specialists assess what type or types of welders are most appropriate for their needs.
Assessing Power Specifications
One of the main concerns when choosing a cost-effective welder is the energy output and the power input. Energy or power output is the amount of power the machine produces, which determines both heat and arc length (with arc welding). Power input is the amount of power required to run it. Buyers should ensure that the welder's capability is adequate for the intended use, and that they can meet the machine's power requirements. Finally, they should ask themselves how energy-efficient the welder is, comparing both input and output requirements.
The amount of power needed varies from job to job. Vehicle manufacturers may specify how much is needed for the car's materials, and shop owners are advised to consult those specifications prior to purchasing welding equipment. Higher output (e.g., 180-200 amps) may be required for thicker metals, such as those used on the chassis of a classic car, while lower outputs (e.g., 100 amps) may suffice for the chassis of a modern car. Resistance welding often requires much higher output, upwards of 10,000 amps.
Some welders require a high level of power to operate, and different welders require direct (DC) or alternating current (AC). Buyers should carefully consider how much energy is available in their shop, and assess whether the purchase of an additional generator, if necessary, would be worthwhile for them.
A welder's duty cycle is also an important specification, as it indicates how long it can be safely used in a 10-minute period. For instance, a welder with an 80 per cent duty cycle needs to rest and cool for two minutes after eight minutes of continuous use. Commercial-grade welders have duty cycles anywhere from 40 to 100 per cent. Duty cycle and power output should be considered together as a way of expressing the welder's capacity for work.
Opting for User-Friendly Welders
Perhaps an overlooked factor in choosing a cost-effective welder is ease of use. Even energy-efficient welders are a poor investment if they are too unwieldy to operate on a regular basis. It is important that technicians feel comfortable and confident using the equipment, so that they can perform their job skillfully and in a timely manner. This usually requires some initial training on the proper handling and benefits of the new welder. Taking the time to do so is likely to pay off in the end.
Consider Welder Repair Service
A final factor in choosing a cost-effective welder is its service support network. In the case of an equipment malfunction, are repairs readily available? How costly are they, and how much time do they require? Researching reliability and the available support resources for different welders is yet another way buyers can assess their cost-effectiveness.
Where to Buy Welders for Car Repair Centres
Welders are available from a variety of sources, including large machine supply shops and speciality suppliers online. eBay is another excellent resource, with an extensive selection of new and used welders, as well as welding supplies and accessories.
How to Buy a Cost-Effective Welder on eBay
To take advantage of eBay's wide range of welders, begin on the site's home page and type keywords into the search bar. For example, you can enter "MIG welder 180 amps", or "stick welder". Refine the search results further if you wish, according to things like price range, seller location, or item condition (new or used).
Review Product and Seller Information
Prior to purchase, it is essential that you review the full item description on the listing. Verify that the power specifications, item condition, and any included supplies are exactly what you are looking for. You should also note whether there are any additional postage fees. Local pickup is an option for some sellers; this is a good way to economise, but should be arranged in a neutral, public area for the comfort of both parties.
Finally, do get to know the seller a bit more. Look at their feedback score and browse comments left by past customers. This helps you assess how reliable and knowledgeable they are, so you can feel confident in the investment you're making in your business.
A quality welder is an essential piece of equipment for many trades and industries, including car repair. Welding, the heating, melting, and fusing of separate pieces of metal, is used in many applications of car servicing, including auto body repair and various modifications. For buyers interested in finding a cost-effective welder for their car repair centre, there are several points to consider.
First, they should assess what kind of welder they need; the most common types for car repair are MIG, stick, TIG, and spot welders. The virtues and drawbacks of each welder type should be compared with the nature of the work they are meant to perform, including metal thickness and material. Other product specifications that should be particularly noted are power output, power input, and duty cycle. Finally, buyers should consider how easily a machine handles, and the cost, time, and availability of repairs in case of a malfunction.
Researching in advance helps car repair specialists find a reliable, efficient, and effective welder for their business.