Choosing the Best Portable Welding Machine
Through heating and then applying continuous pressure onto the welded spot, electric portable spot welding machines are able to fuse multiple metal sheets simultaneously. The term spot welding is used to describe the welding area where the heat and pressure are applied. Spot welding is a form of electrical resistance welding. This process is very similar to a TIG (Tungsten Inert Gas) arc. However, the difference is that there is no need to worry about inert gases or metal fusing compounds to produce the heat and power necessary to melt the metal. Instead, the heat flux is generated from an electrical current passing through a shielding gas.
The first step in every successful welding process requires a shielded consumable electrode. An electrical conductor is used in the weld puddle to create a strong heat pathway. The spot welding machine is used to melt the conductive piece of metal while at the same time providing a controlled water cooling system to maintain the proper arc voltage. The use of water cooling systems is very important, as they help to ensure consistent quality welds and ensure that the electrode remains shielded from corrosive agents.
There are different electrode options available for spot welding machines. The most common type utilizes standard steel (either flat or ribbed), thermoplastic, polyester, and carbon fiber as the shielding materials. One of the primary benefits of using thin, soft electrodes is that it is easy to add more filler wires, resulting in thicker, more welded joints. Thinner electrodes usually require more work to join them together, but they tend to give off less infrared radiation during the actual arc process.
Some welding machines are able to heat and weld at a much faster rate than others can. This is another determining factor when selecting a spot welding machine. It is often important for the welder to be able to move quickly through the process, so the choice of speed is critical. Most welders can complete their work in a reasonable amount of time if they are able to increase the speeds of the weld puddle or apply additional heat at the beginning of each electrode run.
Another key feature that is important for the welder is the ability to determine the appropriate electrode flow. There are many instances where an incorrect amount of current or voltage is needed to weld metals together. A spot welding machine should have the ability to precisely determine the correct electrode flow or compensate for this in some other way.
Many portable spot welders include a safety switch, which allows a user to control the machine and automatically reduce or eliminate the current based upon the resistance of the metal surface being worked. When the user manually reduces the current, a safety cut off switch should be automatically triggered to prevent damage to the welder or to other equipment. The user should also be able to adjust the current based upon the type of power supply used and on the current level being generated within the area of the work piece. The user should also be able to trigger the cut off switch, as well as manually override the automatic start-up procedures of the spot welding machine.