How to select a compact wire feed welder

By Jim Harris
The Lincoln Electric Company

With so many choices of welding machines on the market today, how does a novice welding operator choose what he or she needs? There are a couple of key questions that can guide you through the process and narrow down your selection to make the choice a little easier. Ask yourself the following questions:

1. Which arc welding process best suits my needs?
Beginners will usually turn to either a wire feed or stick welding process, but which is the best one for your particular application? Wire feed welding (also referred to as wire welding) offers a number of benefits. First, it provides higher productivity efficiencies over stick since the wire is fed in a continuous process and you donÕt have to constantly change stick electrode rods as you are welding. Second, wire welding has a lower skill level requirement and can be picked up more readily. With stick, you have to coordinate your hand movements for feeding the electrode rod into the weld puddle, while with wire you just press the trigger and weld. Although there may be some applications where stick might be a better selection, most beginners should look toward wire welding when making their first welding machine purchase.

2. Which wire process is best for me?
Now that youÕve chosen wire welding over stick, the next decision is to choose the type of wire welding you will perform the majority of the time. The category breaks down into two: Gas Metal Arc Welding (commonly called MIG) and flux-cored wire welding. MIG is the best choice when cosmetic appearance is an issue since it provides lower spatter levels. In addition, MIG can weld a wider range of materials, including thinner materials, and different material types such as stainless or aluminum. Since a bottle of shielding gas is necessary with the MIG process, it might not be the most attractive option if portability and convenience is a factor. On the other hand, flux-cored wire welding is the optimal choice for outdoor procedures since an external shielding gas is not required with the flux built into the wire to shield the weld. This process is most suitable for thicker materials where weld appearance may not be as critical. One drawback is that flux-cored can only be used to weld mild steel, so if you are looking to weld more exotic metals, this processes may be too limiting for you. Most industrial products sold through a welding distributor would be equipped to handle both processes. Some manufacturers sell ready to weld packages that include a gas regulator and hose kit

3. What is the thickness of material that will most frequently be welded?
As a rule of thumb, it is recommended to use a MIG process on materials that are 24 to 12 gauge; while flux-cored is only recommended down to 20 gauge. The machineÕs output amperage will determine how thick you can weld. However, in general the Flux cored process will weld thicker than the MIG process with a single pass weld. The material thickness that you most often weld will not only determine the process that you choose; it will also determine the voltage of the unit you need. For instance, if you plan to weld over 1/8" material the majority of the time using a MIG process, it is recommended that you invest in a 230v system. The higher amperage range of this machine can better handle your welding needs in a single pass and you wonÕt have to waste time with second or third passes. Examples of heavy materials can be such things as frames to tool benches or maybe even a fence. If most of your welding will be performed on material less than 1/8" thick, a 115-volt MIG machine is probably your best bet for economic reasons. For flux-cored welding, a 115-volt machine will generally allow you weld material up to 1/4 inch". A 115-volt unit is less expensive and will well suit your needs. When choosing a machine, look also at the amperage ratings of the machine Ð you donÕt want to overburden a machine by continuously welding at an amperage higher than what is recommended.

4. What input power is available?
Another key question to ask yourself is what input power do you have available. For instance, if you will be doing most of your welding in your home or garage, you may only have access to a 115-volt input power source -- this will limit your selection to a 115-volt wire welder. If you have access to 230-volt power in your home due to special wiring or are doing most of your welding in a job shop, you may look to a machine that has higher voltage capabilities (230-volt is usually readily accessible in an industrial setting).

5. WhatÕs your budget?
There are a number of technology features that set one compact wire feed welder apart from another. For instance with both a 115-volt and 230-volt machine, you can purchase either a tapped or continuous control model. Tapped control basically offers you four or five discrete voltage settings. With continuous control, you have a continuous range of settings that can provide for fine adjustments and heat control. The continuous control is a nice feature, especially when working with thin materials where a finer heat control helps to achieve an aesthetically pleasing weld Ð this fine control is typically more expensive than tapped control but will benefit those welding a lot of thinner sheet metal.

6. WhatÕs included in the package?
Not all compact wire feed welders offer the same accessories in their package. Pay careful attention to what is included. For instance, Lincoln ElectricÕs small SP models of wirefeeder/welders come complete with a regulator, hose and even a sample of MIG wire (select models even come with an instructional video). The only extra item you will need to purchase to be ready to weld is a tank of gas.

7. What is the quality of the machine and the manufacturer?
It is always recommended to buy from a recognized name in the industry and to make sure that the machine carries a warranty. Also, check to see that the manufacturer offers technical support on-line and over the phone. In this way, if you have technical application problems, you will be able to get them answered without hassle.