receive any liquid or dirt which may be present or in the process of falling onto the guide track such liquid and dirt accumulating in groove 32 is carried around the guide track by successive wires contaminating not only the guide track but also the knotter and gripper mechanisms above the bale and even the wire drive 24 when the wire feed is reversed to tighten a wire loop about a bale in the present improvement an upper contamination deflector 40 has an inclined upper portion with its top edge bearing resiliently against frame plate 30 above the guide track 22 the lower portion of deflector 40 is mounted on a bar 42 above and spaced forward from guide track 22 as shown in fig4 this prevents any liquid or solid material from falling on or into the guide track when the wire is being stripped from the guide track it moves deflector 40 outward momentarily in the region of the wire as the wire moves along the upper edge of the deflector as shown in fig5 this is only a momentary movement of the deflector and it immediately returns to its fig4 position to intercept any falling liquid or solid material as a further safeguard against contamination in the lower guide track a second deflector 44 is also provided this deflector has an upper portion inclined outward away from the plate 30 in the opposite direction from the inclination of deflector 40 the upper portion of deflector 44 normally overhangs the guide track as shown in fig4 the lower side of deflector 44 is pressed by.