I just made my homemade stick welder using microwave oven transformers (MOT). They work great for me. I have been practicing welding for some time and I want to share some important information with everyone to help safe and good welding so I have written this article on arc welding to help home welders, hobby welders or any garage welders. Arc welding requires a constant arc to melt the filler rod and heat the base and joining metal to get fused. I will tell few things that are very much important and should be remembered for good and safe welding. The very first requirement is an arc welder. Read this article and learn to build one. See also arc welding requirements.
Then we need some welding protection gear like helmet, mask, gloves etc. You can find them easily or you can buy them cheap at amazon. After you have gathered all the equipment it is very important to have good and sound information about welding. At first let me start by explaining the work mechanism of an arc welder. There are two types of arc welder available now days, Transformer powered welder and Inverter welder. In my project I have made a transformer welder because it is cheap, traditional and we don’t need any knowledge of electronics but in inverter welder the electronics circuit provide required power so you need good knowledge of electronics to build it. Most users have transformer powered welders and we also talk about the here.
The welders take input power through wall outlets of house that is 110v or 220v according to location worldwide. (Fun Fact: Nepal used to have 60V supply before the standard 220v came in). The wall outlet has high volts and less amps that will give power which is (Watt=Volts X Amps ). In emergency case you can use car batteries to weld too. Just put two or if possible three 12 volt car batteries in series and then use and electrode holder to handle electrode and other to connect the ground clamp to base metal.
The welder converts the high voltage low current to low voltage high current which makes it safe and suitable for welding. The two output is taken to create a short circuit to create an hot electrical arc to melt metal. One terminal is known as stinger or electrode and other is ground.
The welding output voltage of my homemade welder is 38 volts which runs on 220V input. Many of experts prefer 220V welder instead of 110V due to good duty cycle and the great built quality of transformers to handle 50 Hz electricity. So I advice people to make 220V welder even if they have a 110V wall outlet. Then can use two sockets which are 180 degrees out of phase and put the primary of transformers in series. Now let us begin with preparation for welding.
To have a good welding the size of metal, electrode type, metal type, welder settings must be appropriate. The welder should have good knowledge of electrodes and welding position and techniques as well. Use welding gloves, masks, cover and shoes. The arc of welding is brighter than sun and can be hotter up to 2000 degree Celsius actually and the UV Radiation is pretty harmful to give you a burn so be careful. At first lets know about the electrodes. There are various types of electrodes available and each have its own specialties.
If you are a hobby welder and don’t tend to be so much technical and just do small and light fabrication the 2.5mm E6013 electrode is the best. It is the most common rod used worldwide. It works on DC + or – and AC too so it is awesome. (The first two digits represent the tensile strength of rod or filler metal, 60 thousand PSI. There are rods up to 100 as well like E10018). E6013 is the E6010 or E6011, these are also mostly used in welding pipes because they do good penetration and can be used for good open root welding. E7014 is also rod working on any current which is told to be the highly efficient.The best and the strongest rod is E7018, with some practice if you can handle this rod good then it is the best rod for everything. Heavy duty welding like water supply pipes are welded with this. Its low hydrogen property makes it good for weld and the slag cover is also less than E6013.
The major problem for starters is to strike an arc, I also had this problem first, the rods would just stick to metal and the welder would make “hmm…” sound hard and they heat up. You will have to loose the rod at that moment to be safe and protect the welder. I used to release the rod by loosing the clamps or holders. Striking an arc is just like striking an match stick which is a cliche. Try to learn from some YouTube videos. After striking learn to maintain it and balance it and control the puddle. Most important stuff “Keep the arc as short as possible” because it is easy to balance and control. Try to push the puddle and slide away the slag at top because they can leave voids and puddles. If you have a welder with current control then it is obvious that you should keep low current for thin metals and high for thick ones. The cliche is that when the current is right the weld sounds like “Bacon Fry” and if it is high then it will be a loud noise. You will learn it yourself. Learn good skills on flat and horizontal before welding overhead. It is extremely dangerous because there will be splatter all over and weld bead should be controlled well. Some important things to remember:
1) Try not to weld Galvanized iron without as gas mask because the gas from zinc is carcinogenic.
2) Never ever touch two output leads at 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 a MCB switch.
Enjoy happy and safe welding.