Pitting reffers to the weld being pourus. as in, filled with tiny holes. the weld will fail from cracking.
Being a good welder is welding absoultely as hot in the specified range your welding specification says you can weld at, and still maintain control the weld.
abustiffy - when the toes of the weld flow below the surface of the base materials, that is undercut. Undercut is cause by too low of a travel speed (for the voltage), or incorrect torch angle. Using the classic C25 (75/25% ar-co2) mix for mild steels will virtually eliminate all, but the most sever undercutting on ferrite materials. It will also flow better, and the present oxygen (from the breakdown of the co2 gas in the arc) will help maintain the puddle flow (wetting action), along with help flatten the bead.
C25 limits you to short circuit welding. Not bad for the newbies. All position, low WSF (wire speed feed & amperage go hand in hand with mig), good for thin material.
You can use it with globular also. Alot more WSF (i.e. hotter & more material deposited), spatter. You're limited to 1F & 2F weld positions (flat & horizontal fillet welds.... T joints.)
Most of the people on "those" shows can't weld worth a ****. They approach operator levels of, "I can tack weld".
Normally, if you see one of them that actually makes a quality weld. It's because they've got a newer machine that has pulsed transfer. Which, is the best thing ever, literally. Even grossly lowers the operator skill level.
You basically wrap almost all of the positive features from the other 3 gmaw transfer modes, add a gross cost savings on materals & the only downside is that you need a mahcine that can do it, which is alittle more initial cost.
You can always tell when they do it too. The welding will sound more like a high pitched growl instead of an arcing sound. It's a slightly lower tone.
