6010 & 6013 ar not interchangeable, about all they have in common is that they are both welding rods. 6010's penetrate deep & freeze fast, 6013's don't do either. They handle entirely differently.
Hello cole, they are substantially different rods, E6010 and E6011 electrodes will act similarly, but the E6010 is for DC use only and the E6011 electrode can be used on either AC or DC current. The E6013 can be run on either AC or DC current as well, but will run considerably differently. It is great that you got this rod from someone, yet it won't provide you with the same sort of practicing experience that you are receiving at school. Especially for practicing root passes. The flux make-up of the two rods is completely different and the penetration and bead characteristics are not the same. Save the E6013 for something else. E6010 and E6011 are deep-penetrating, fast freezing electrodes, E6013 is a shallow-penetration fast freezing electrode with a full-coverage slag. Best regards, aevald