Hi paulvoss,
Most common poly tarps are polyethylene. If you know you have a different material (cloth, polyester, urethane coated, etc.), comment below as the suggestions may be different.
Polyethylene is difficult to bond with adhesives because of it’s low surface energy (LSE), but we do have several products that are designed for LSE bonding. Here are a few options to consider:
3M™ Hot Melt Adhesive 3748 – Hot melt adhesives will flow into the texture and remain flexible after cooling.
3M™ Scotch-Weld™ Structural Plastic Adhesive DP8010 – Structural adhesives will be more rigid but may deliver more strength.
3M™ Adhesive Transfer Tape 9472LE – Tapes may be an option depending on the specifics. The texture of the tarp may reduce contact area and strength of the bond.
Comment below if you have additional questions about this.