Originally Posted by two stroke mick
I worked up the courage to remove the clocks (tacho and trim) from the boat only to find that there was no sealant of any type used to them in.
To be fair - you shouldn't have to use sealant. If the holes are cut to the right size (tight fit - no carry on jokes please) - then the rubber seals that come with the instruments should be adequate, as long as there's sufficient pressure on them. In my opinion - it's better not to seal them, especially when it comes to changing 12v bulbs, etc. Fixed VHF radios, battery isolators, switch panels - then yes, they should have a bead of sealant on them. Tinned cable will reduce corrosion issues too.