I replaced a valve in my Hypalon RIB and it's got a slow leak. It's the type that screws on so that the outside half clamps the inside half, and uses compression around the perimeter to seal against the fabric. I have the tightening tool and have tightened it as much as I'm able, but the dinghy is about 13 years old and the fabric that was compressed under the old valve probably doesn't have as much elasticity as when new, so that's why its leaking.

So bottom line is I need to use a sealant beneath the perimeter ring and I'm deliberating about what type. As I'm writing this I'm thinking either butyl tape or beeswax (from a toilet bowl ring). Leaning toward beeswax for future serviceability and cleanup if needed. Anyone else have an opinion? (Ha, as if this group is short on opinions. )