Denzo

Gooey, petroleum-based British plumber's tape, Denzo is popular with the BCU crowd...likely due to the availability of Denzo to the Brits.

Denzo is a loosely-woven fabric coated with a tar-based adhesive. This adhesive never really dries, but will stick to a boat hull for repair even in cold or wet conditions.

Many paddlers stick a piece of Denzo to aluminum foil or plastic wrap to both keep it from sticking to itself in a repair kit, and also to provide a smooth, non-sticky face to the repair once it's on the boat.

It can be cleaned with mineral spirits back home and a permanent hull repair can be made.