Weld Mold 4115 description: 4115 is commonly run DC+ polarity however if arc blow is an issue than 4115 can run on alternating current (AC) which will alleviate the magnetic forces that cause arc blow. Joints must be exempt from grease, cracks and any other form of contaminant. Guide electrodes with a slight declination, weld with a short arc and avoid high heat input by applying the stringer bead technique (weaving max. 2-3 times core wire Dia.)