how to ...

[Scoobimax]

... waterproof a seatbelt mount bolt off the outrigger/chassis?

mine leaks when the road is wet and spray is kicked up.

will undoing and using something like PTFE tape work?

ta

[Barkychoc]

When rebuilding my car I put a circle of blue hylomar around all the bolt holes, nothing comes in at all. Any sealant would do I guess.

[Donnysoutherner]

Won't be the thread that's the problem Max, more to do with the big hole in the bodywork it goes through! Lots of silicon sealant I reckon.

[Scoobimax]

cheers.

B&Q i guess.

[phillpot]

"Sikaflex 221" is the stuff to use (imho) far superior to silicone, you'll find it on Ebay or at a chandlers.