If you are a welder or trying to learn how to weld, I’m sure you are aware by now that when joining two metal pieces together you will have to make a weld pool and you will use this like a glue to stick the pieces together. Of course, if you are looking for the best way to carry a welding puddle in a flat position – that would be slowly.
There are several way that you can run a weld bead along a joint. Sometimes, though, welders have a hard time doing this because of the awkward positions that they have to do. You may have to weld from a narrow space, under the car, under water, and a lot more positions that is required in your job. We also have gravity who plays a big role when it comes to molten metal that gets deposited between metal plates or pipe sections. For example, if you are welding overhead, you have to keep in mind that speed is important. You will have to move faster than normal, because if you are slow the weld metal may end up dripping on your face shield rather than connecting the two joints. You have to consider the appropriate joint that you will be using, and the right machine. Let’s also not forget that you have to have the right hand position, stroke, and speed in order to be able to get the bead down properly.
Here are some common bead types that are used in shop or in field:
- STRINGER BEADS
When you say, “Stringer Beads” this usually refers to a straight forward bead wherein you have a choice whether you want to drag (pull) or push the torch across the joint with minimal side to side movement. If you choose to drag, it is simply when the electrode is pointed back towards the puddle, and you leading it. After the work is done, you would notice that the penetration is maximum and it looks like a robust-looking weld.
If you are dealing with heat sensitive or thin metals, or even just welding in a vertical up position, welders must keep in mind that you have to “push” the torch. You have to point the electrode forward. You see, when you are welding in a vertical up position, because of the effects of gravity, the molted metal will want nothing more but to fall downward so a way to counter this would be to direct the heat away from the puddle and allow the weld to solidity quickly so that it will have no time to drip.
Stringer beads can be used in any welding position because they are generally not very wide.If you are moving in a straight line, it is important that you make sure that you will get to tie in with the toe of the weld on either side. Keep in mind that the object that you are welding is not just to fill a joint with a new metal. You have to create a fusion between the weld and base metal. If you move the torch along in a slow motion, the weld puddle could flow over to both sides of the joint.
- WEAVE BEADS
If you have to weld a wider one, you can try to weave it from side to side along a joint. If it is a fat joint, the process of weaving is the quickest way to get the job done. This is also true in the case of groove welds on thick stock. On fillet welds, weavers are also common.
There are different types of weaves, and each welder can choose which one they would like to do. They can choose between doing a zigzag type, a crescent type, or a curlycue technique.
Weaving is also useful when you want to control heat in a weld puddle. Remember to pause on each side of the weld in order to achieve a good tie in and prevent an undercutting on the edges. Just like the first one, speed is also an important factor in weaver especially if you are moving across the center of the joint. If your speed is too slow, you may end up with what they call as a “high crown”, this usually looks like a bulge in the middle. A flat of a slightly convex weld face looks much better.
If you are interested in doing a triangle weave, it is useful when you need to fill a steep pocket. If you are vertical up welding again, this triangle weave will allow you to build some kind of shelf behind the puddle, and this stops the molten metal from sliding forward.
If you want to stop the puddle from overheating, or expanding some more, you can try the semi-circle weave, with the center point or your stroke crossing the front of the puddle —- just a little bit ahead of it though. However if you want more heat, you can still use the semi-circle technique but you do it at the back through the puddle.
- WHIP MOTION
Next we have the whip motion, this is common on open groove welds, wherein the welder performs this motion with his or her wrist on the root pass. The main goal when you do this is to fuse the work plates together at the bottom with a flat bead of a weld metal. The welder will have to drive the electrode up through and along the gap, which is essential when you are trying to achieve a complete penetration. You may see a keyhole appear at the opening of the head of the puddle.
Whip motion is a difficult stroke. The control of heat is very crucial. You do not want to expand the key hole beyond control because when it gets too big, it would be impossible for you to weld the sides together. You will have to whip the rod a little upward and ahead of the weld. This enables it to cool down and keep the keyhole at the same size.