The weld puddle has been mentioned a lot on this thread, but I wanted to discuss what this is. Understanding this, I think, made me better at laying down solid welds even though they aren't all "pretty". I'll focus on wire fed/short circuit welding since this is what the majority of us use, but the principle is the same for the majority of arc welding processes. When the arc is initially struck it starts to heat up the base metal to a molten state creating a dished puddle. At the same time, it is melting the wire into little droplets that fall into the puddle & promote fusion. If flux is involved then it is also being melted and creating a gas pocket around the arc & weld puddle.
Essentially what dictates the shape/size of the puddle are the volts & amps. Higher voltage, sometimes called "heat" will make the puddle wider & shallower. I'd like to add that if the end of your wire gets farther away from the puddle then the voltage will increase. You won't be welding at the settings you think you have; the metal will get hotter & more fluid making it harder to control. On the other hand, if you increase your amps also called current or wire feed speed (WFS) the weld will penetrate deeper. Also, the increased wire going into the weld puddle will cool it down. I suggest finding some scrap to help you find the balance between amps & volts that works best for you.
When you look at the puddle you want to make sure that it is slightly dished in front & humped up at the back. You should also see the edges of the puddle smoothly transitioning to the base metal along the sides. At the leading edge of the puddle you should see both sides of the base metal melting into the puddle equally. Sometimes you will see a small dot floating around in the middle. This is the impurities floating to the surface & burning off which is normal. If it looks like its boiling or spitting out globs of molten metal then stop
Common puddle troubleshooting:
- If the wire feels like it is pushing you back: WFS too high or Voltage too low
- If small droplets are forming on the end of the wire & you hear a hissing sound: WFS too low or Voltage too high
- If the arc seems erratic: Base metal is not clean enough or your Ground Clamp is not connected to clean metal
- If it looks like the weld puddle is covering the end of your wire (typically occurs welding vertically downward): You’re moving too slow or your WFS is a little high
- If the puddle is not filling up as you move: You’re moving too fast or your WFS is a little low
Odds are that if you send me a picture of your weld I’ll be able to tell you what’s wrong or at least guide you in the right direction