What causes excessive spatter during MIG welding and how do I fix it?

Excessive spatter can be caused by wire feed speed that is too high, voltage that is too high, electrode extension that is too long, dirty workpiece, insufficient shielding gas at the arc, dirty welding wire, or incorrect polarity. Corrective actions include reducing wire speed or voltage, shortening electrode extension, cleaning the base metal of grease/oil/rust/paint, increasing shielding gas flow, using clean dry wire, and verifying correct polarity per Section 3-5. (Page 39)