We have a full step by step guide on building homemade stick welder using microwave oven transformers (MOT). Welding is amazing, and it is a great skill to have. Therefore I want to share some information with everyone to help them learn welding. I have written this article as an arc welding guide to help home welders and hobby welders. Arc welding requires a few essential pieces of equipment, knowledge, and skill, which I will explain. I am now an expert so this is from a view of a starter.
The first and most important thing is clear knowledge. We should know our equipment and the process involved in our work. Then we need a welding machine, protection gear like helmet, mask, gloves, etc. You can find them locally, or you can buy them cheap at Amazon. Gathering equipment is the core part of the work. It is also very important to have good and sound information about the process. Arc welding or stick welding requires a constant arc to melt the filler rod and heat the base and joining metal. For this, we use electricity. We need a high current and a lower voltage for this process.
At first, let me start by explaining the working mechanism of an arc welder. There are two types of stick welder available nowadays. Transformer powered Inverter welder. In our project, we have made one using old microwave oven transformers. It is cheap, traditional and we don’t need an in-depth knowledge of electrical systems. In Inverter welders, the electronics circuit provides the required power, so you need a good understanding of electronics to build it. Take whatever path you think is good for you. You can also buy one from the store.
The welding machine takes input power through wall outlets of the house or workplace. That means it could be 110v or 220v-240v AC. The wall outlet has high voltage and fewer amps. But there is a tremendous amount of power (Wattage=Volts x Amps ). So be very careful while working on these things. In an emergency case, you can use car batteries to weld as well. Just put two or three 12 volt car batteries in series. Then use one terminal as an electrode holder and another to connect the ground clamp to the base metal.
A regular welding machine converts the high voltage low current input to low voltage high current output. The process may use a transformer or an electronic circuit. This makes it safe and suitable for welding purposes. The two outputs terminals are taken to create a short circuit. This creates a hot electrical arc to melt metal. One terminal is known as a stinger or electrode, and the other is ground.
The welding output voltage of our homemade welder is 38 volts. Our input is 220V AC from the wall outlet. Many experts prefer a 220V welder instead of 110V due to the good duty cycle. Another reason is the excellent built quality of transformers to handle 50 Hz electricity. So I advise people to make 220V welder even if they have a 110V wall outlet. You can use two sockets, which are 180 degrees out of phase, and put the primary of transformers in series. If you can’t do this, use 110v input for your transformer.
Knowing the Basics
To have a good weld, we must be careful about the size of metal, electrode type, metal type, and settings. The welder operator should have good knowledge of electrodes and welding positions. Always use heavy-duty gloves, masks, cover, and shoes. The arc of welding is very bright and hot, which can be hotter up to 2000 degrees Celsius. UV Radiation is also emitted, and it is pretty harmful to give you a burn. So be very careful while working.
Read More: Arc Welding Requirements
At first, let us know about the electrodes. There are various types of electrodes available, and each has its specialties. Most of you are a hobbyist and don’t tend to be so much technical. Most of you might just do small and light fabrications. For those people, the 2.5mm E6013 electrode is the best choice. It is the most common rod used worldwide. It works on DC + or – and works on AC as well. The first two digits represent the tensile strength of the rod. 60 means 60 thousand PSI tensile strength.
E6013, E6010, and E6011 are other popular rods. These are also mostly used in welding pipes because they do good penetration. They can be used for suitable open root welding. E7014 is another rod that works on any current, and it is told to be highly efficient. The standard best and the strongest rod is E7018. Its low hydrogen property makes it suitable for weld, and the slag cover is also less than E6013. If you want to be better in this business and skill, go in-depth on this topic. Actually, good rod selection is very important. Knowing the electrode material and their use is very crucial.
Starting the arc and Safety Tips
First of all, these are some important things to always remember while welding.
1) Try not to weld Galvanized iron without a gas mask because the gas from zinc is carcinogenic.
2) Never ever touch two output leads at the same time.
3) Keep the welding area ventilated.
4) Be safe from any touch or connection with primary.
5) Install suitable fuse or circuit breaker for primary, I prefer an MCB switch.
Safety is a very important thing to learn from our arc welding guide. The major problem for starters is to strike an arc. I also had this problem. At first, the rods would just stick to metal, and the welder would make “hmm…” sound and heat up. You will have to lose the rod at that moment to be safe. People say that striking an arc is just like striking a match stick. Try to learn from some YouTube videos of other experts. After striking, learn to maintain it and balance it and control the puddle.
The most important stuff is keeping the arc as short as possible. It is easy to balance and control when the arc is short. Try to push the puddle and slide away from the slag at the top because they can leave voids and puddles. If you have a welder with current control, then it is apparent that you should keep low current for thin metals and high for thick ones. The saying is that when the current is right, the weld sounds like “Bacon Fry”.
- How to Arc Weld: WikiHow
- Original Published: 2014/10/28