Welding metals is a process requiring a huge amount of power. Arc welding equipment requires a suitable power supply with the right voltage and current. The voltage helps to create and maintain arc while current is needed to generate heat and melt the metal. It means both base metal and electrode or filler metal. Here we have compiled some information from our experience on arc welding requirements. This is to help the starters and interested people. Here we cover the skills, knowledge, equipment, supply, instrument, and basically you need to learn for this job. It is from a beginner’s perspective, and it is meant to guide in the right path.
We want to educate our readers on arc welder basics and the parts mainly. Our aim to give information about all the parts that are active in the process. We should know the process and science behind our tools to understand it better. It is good to know about what we are working with. The main parts are a power source, converter, cables, and holder. Everything needs to be in perfect condition to get the best result. Most of all, safety is the primary concern before working with any of these things.
Good Power Supply
Arc Welding requires a constant voltage and current. It is usually provided by sources like traditional transformers or new inverter circuit. The latest models have DC supply mode in them. It is very good because some rods require DC in specific polarity. For example, Aluminum needs certain polarities in DC power. For Aluminium welding, DC power is recommended. But aluminum welding with an arc welder is not recommended by experts. We only suggest to weld all iron except galvanized iron. The zinc fumes are carcinogenic and harmful. So weld them in the open, ventilated areas wearing a good gas mask.
Always try to get the best power supply for yourself. If you are planning to do some light fabrication, then a small portable one might be sufficient. However, for heavy fabrication work, including thick metals, a bigger and powerful one is required. Small supplies can’t supply good voltage and current, causing weaker welds, less penetration, and bad work. The duty cycle is another aspect to look at while purchasing a new welder. Therefore be very careful while buying or making a machine.
Rating and Source
While building an arc welder, we learned new things. We got new knowledge after making mistakes. We also learned from looking in some forums and consulting with welders. Always try to weld with enough voltage. Mostly minimum of 30 volts is required to get a smooth arc. About a minimum of 100 amps of current is also required for this job. It is because if we use less current than that, we will be running too cold, and the penetration is not going to be well. But if we go very high, our puddle will splatter, and there may be big penetration.
A good welder can go about 3000 watts and more. While using such higher wattage systems, make sure your breaker can handle it. Household and workspace mains should be well enough to handle such power demand. Some people might have a small 15 Amps breaker for 220V supply, which usually trips with a heavy load. In order to ensure safety and good supply from source, use safer and bigger breakers.
Safer and Thick Cables
We should have seen the use of very thick cables during welding. The input or feeding cables are medium size, but the output cables are massive. Mainly they are very thick in order to carry the massive current. Carrying high voltage doesn’t require thick wires, though. The thickness order is mostly like this (Jumper Cable>Secondary Cable>Primary Wire). The voltage is always inversely proportional to length. When the length increases the voltage decreases. So be careful about your cable length for adequate power supply.
As the wire gets away from the source like the transformer, the voltage starts to drop in relation to distance. Therefore thick cables should be used to prevent voltage drop and to handle the enormous current. AC actually makes the electrons vibrate in the wire. Whereas in DC, the electrons flow smoothly. In the first test, we used 12 gauge wire instead of jumper cable, so they started to heat up quickly, and starting arc was also challenging. Then with 25 mm jumper wires, the work became very smooth. Those thick wires handle current and heat very well.
Protection Gear and Safety
Safety should always be our first priority. Always use good protection while working. Make sure all electrical equipments are well-grounded. Make sure you are in a safe place far away from explosives and flammable materials. Work in a dry place as far as possible and take all the preventive measures while working in wet areas.
Read More: Welding Guide for Basic Beginners
Do not touch hot metal immediately after welding. The filler rod, base metal all become extremely hot after work. Never touch both leads at the same time. And don’t ever touch any wiring with bare hands. We recommend using thick protective gloves, welding mask with air filters. Turn off the supply from mains and disconnect everything before trying to make a repair attempt.
Original Published: 2014/11/06