Welding metals is a process requiring huge amount of power for welding equipment. Welding requires a good power supply with good voltage and current. The voltage helps to create and maintain arc while current is required to create heat and melt the metal. It means both base metal and electrode or filler metal. I have complied some information from my own research and experience.
Supply: Arc Welding requires a constant voltage and current which is provided by sources like traditional transformers or new inverter circuit welder. Latest models have DC supply mode in them. It is very good because some rods require DC in specific polarity like Aluminum. Aluminum rods are best if welded in DC. But aluminum welding with Arc Welder is not recommended. We only suggest to weld all Iron except galvanized iron. The zinc fumes are carcinogenic and really harmful, so weld them in open ventilated areas wearing good gas mask.
Rating: While building an arc welder I got some new information by doing things, making mistakes and looking in some forums and consulting with welders. Try to weld with enough voltage that is a minimum 30 volts to get a smooth arc and a minimum 100 amps because less than that you will be running too cold and the penetration is not going to be well. So it is a guarantee that good welder won’t be less than 3000 watts.
Read More: Homemade Arc Welder
Why Thick Cables?
I have seen too many welders and the thing that came to my mind is that why are the welding cables or jumper cables so think while the secondary is not. The thickness order is mostly Jumper Cable>Secondary Cable>Primary Wire. After some research, I found out the simple physics involved. The voltage is always inversely proportional to length. If the length increases the volt decreases.
As the wire gets away from source like transformer the voltage starts to drop in relation with distance so thick cables should be used to prevent voltage drop and to handle huge current. The AC current actually makes the electrons vibrate in the wire where as in DC the electrons flow smoothly. A DC welder is a recommended one for Arc welding specially for Aluminum welding. I used 12 gauge wire instead of jumper cable so they started to heat up quickly and starting arc was also hard. Then with 25 mm jumper wires that cost me $1.5/m was good enough to weld and start a smooth arc.
Protection and Gear
Always use good protection while working. Take care of yourself and the environment. Make sure you are in safe place far away from explosives and flammable materials. Work in dry place as far as possible and take all the preventive measure while working in wet places. Never touch both leads at same time and don’t touch any wiring with bare hands. We recommend using protective thick gloves, welding mast with air filters. Make sure the working piece is clean and safe to work. Enjoy your work and learn from every step to improve your results and actions.