Clifton Hypalon® Adhesive FA4844 is your best choice for unsurpassed adhesion.
NRS uses it when building their Pennel Orca® boats and highly recommend it.
For an even stronger bond and faster cure time, mix with Clifton Hypalon Accelerator, Item # 38702.01. Accelerator ratio: 0.8 oz. to 1 gal. glue.
3.5 ounces should cover 1-sq. ft. of patch (both surfaces), with 3 thin coats.
Look for plastic mixing cups at paint or hardware stores. They have volume markings that let you measure the right amount of glue. You can also do a web search for "graduated plastic mixing cups."
NRS uses Clifton Hypalon Adhesive to bond Hypalon to Hypalon, but this adhesive may also be used to bond other synthetic rubber materials, like neoprene and EDPM.
Shelf life: 1 year