Portable Spot Welding is an electrical procedure of welding metals together. Through applying continuous pressure and heating the welding spot, portable spot welding machinery is able to fuse multiple metal sheets instantly. The term portable means that the welding process is performed in a portable atmosphere, usually a welding machine or a handheld welding gun. The most popular type of welding used in portable spot welding is mig welding, because it offers the ease and safety of hand held equipment with the portability of on-site equipment. The term portable in this welding process refers to the location where the heat and pressure applied are carried through the weld puddle.
MIG welding is one of the most commonly used types of welding, because it has proven to be very reliable and efficient. This process uses a tungsten electrode (usually a Flux Cored Metal Arc Welding (FCAW) wire) and creates a strong heat that joins the joined pieces. The process uses both a filler metal and a short circuit to control the arc and to keep the weld location closed. When using MIG welding, there is a built-in trigger that causes the machine to stop once the weld puddle cools down and the maximum amount of current is flowing through the wire.
Because the MIG welding machine uses a tungsten electrode and a high current, the output current is relatively low. For this reason, MIG welding machines are typically used in less-than-ideal places. Portable electrical devices, such as a hand held portable welding gun, or a battery operated welding machine; do not have sufficient output current for a business to rely on. To compensate for this, most portable welding machines use a welding pencil. Welding pencils are built with a fine tip that creates a very sharp welder tip, allowing for higher arc speeds and more precise welding.
The other key disadvantage to using a welding pen is the battery. A welding pen uses a standard small size lithium battery. These batteries are not designed for long term use and will eventually need to be replaced. As the batteries begin to diminish, so does the life of the weld. In addition, the larger the welder pen becomes, the more it will cost to replace the battery.
The final disadvantage to using a welding machine is that there are significant delays between the time the operator starts the process and when the welder actually begins welding. This results in an increase in machine wear and tear, which shortens the overall production time of the machine. Depending on the quality of the raw materials, a small weld may not be adequate for the job at hand. Because a MIG welding machine is so quick to start, and because the pulse invention time is small, the overall weld production time can be shortened without sacrificing on overall machine productivity.
One final disadvantage to using a welders is that the metal and wire often come into contact with the hot surface during the start up process. The metal and wire often become fused together before the arc has been created, reducing overall machine quality. Depending on what is being welded and how thick the metal strip or other weld areas are the weld could be pushed through the feed plate and heat up the feed plate causing the metal to become fused. This would negatively affect the ability of the machine to weld on thicker metal, especially plated steel strip.