Learning how to properly strike an arc when arc welding can be quite a headache. There are a few methods to strike an arc and we will go over them here. The one thing that probably makes it the most difficult is that you cannot see what you are doing, so I strongly recommend getting an auto darkening welding helmet. It will probably be the most important investment you will make on your quest to learn how to arc weld.
The basic theory behind how to strike an arc is simple. You must make the metal of the electrode contact the metal you are welding on. It must then be immediately drawn away from the metal about 1/4 of an inch. If you do not draw it away it will simply stick to your work. If that happens a quick twist and tug will usually get it loose. If it doesn’t break free on the first try you will want to squeeze the clamp on the electrode holder and pull that away. Keep in mind any time the electrode is stuck to your work, the welder is being shorted out. This will cause it to overheat much quicker, and may blow a fuse or breaker in your breaker box.
There are a few techniques on how to strike an arc, I recommend you try them all and see which is most comfortable for you. Remember, practice is the key to being a good welder. The first method is the jab method. The way this works is you position the electrode about 1/2 an inch away from your work. Then flip your helmet down. Now you want to quickly jab the rod into the work then immediately pull it back. Another method is the scratch method. This method works very much like striking a match. Just imagine the electrode is the match, and the location you wish to lay your welding bead is the striker. If you make sure to use a very quick stroke you are much less likely to have your electrode stick when using this method.
One common problem people have is that no matter what the electrode simply freezes to the work. If you are experiencing this, it most likely means that the amps need to be turned up on your welder. Try turning it up 10 amps at a time until it stops sticking. If you are having success getting the arc to start, but then it immediately goes out, you are pulling the welding rod too far away from your work. Remember, you only want to pull it back about a 1/4 of an inch.
Once you have the arc going, you need to immediately start feeding the electrode into it. The electrode will get burned up fairly quickly, so you must keep it at the correct distance to maintain the arc. When it is at the correct distance it will make a crackling noise. If you get it too far away it will be more of a popping noise with sparks flying in all directions. If it is too close you will see the arc start to go out and it will make much less noise. If the arc goes out after you have been welding a little you can restart it much easier while the metal is still molten. Simply stick the electrode back into the puddle while you can still see it glowing through your mask.
Sometimes it is necessary to have the arc start in exactly the right place. This can be difficult without an auto darkening helmet. One trick is to place a small piece of scotch tape on the metal that ends right where you want the bead to start. This way you can place the electrode on the tape with your helmet up, then drop your helmet and simply drag it off the tape.
Learning how to strike an arc can be one of the most frustrating steps in learning how to arc weld. Fortunately, once you get it down, it becomes almost natural. Learning how to arc weld is mostly a process of practice. Get yourself some scrap metal and spend a few afternoons burning up electrodes before you try to weld anything important.