Welding Tips and Tricks

Can anyone give us noobs tips on how to avoid undercutting? I have read in several books that it is caused by improper settings on the machine, ie..current set too high. I have also read that it is caused by improper torch manipulation. I have tried changes, but still seem to undercut. The other problem area is coming to the end of a weld on a butt joint, can't seem to add enough material to build it up and make it flush. Always seems to drop out and leave a void. Any tips?

For me, holding longer in the puddle allows more filler metal and less undercut, also your heat may be a little high. At the end of a joint, I find that pulling off of the metal and allowing the puddle to cool and then striking again, a couple of times allows it to become flush.

definatly a little more "pause" at the edges of the joint its possible that its all about being to hot, but you'd have to be pretty damn hot to not be able to fill out a joint with proper technique, try slowing the whole operation down a little bit and if your sticking, shorter arc length will help to this does a couple things, A: lowers your amperage a bit B: deposits more metal in a shorter time at less heat. as for the crater at the end, its gonna happen unless you A: use crater backfill setting on your machine (mine has none Haha) B: use a step back technique at the end of the bead basically just do a little loop back to where you anticipate the crater to start and then slowly run over it again hope this is helpful!

clean, clean, clean. any mill scale, rust, or any other contaminates will cause undercut along with what the other guys said.

step out of the weld puddle while maintaining the arc then step back. undercuts a bastard. heat input, rod angle, rod manipulation. slow down and watch weld flow out. most times its a very small and simple solution. keep the frustration to a minimum