I just found out more details about the butyl sealant from the autoparts store from Earthmover84.
"you can put on your DIY that 3M Windo-Weld Ribbon Sealer works to, just got some. it does contain polybutylene, and butyl. thought i might let you know. AutoZone and Advanced Autoparts both carry it. part number 051135 08612" - Earthmover84 