I used to do contract phone line work, and we used this a lot in outside applications. It seals and adheres to the wire casing. Pretty good stuff.
http://www.grainger.com/product/POWER-FIRST-Cross-Linked-Polyolefin-WP121199/_/N-8iiZ1z0kazg?_=1409054844255&s_pp=false&picUrl=//static.grainger.com/rp/s/is/image/Grainger/4RCT9_AS01?$smthumb$
You can highlight and right click, open link. For some reason it doesn't want to paste right.
