Sealing 240v hook up

[Petest]

I'm slowly getting the bits I need to start a conversion.

I've bought a 240v hook up (the type that you drill into the bodywork). It comes with a foam rubber seal.

Is this seal enough to make it water tight or should I put some sealant of some sort in 1st?

[imageoven]

probably....

my toilet cistern sealed with a foam rubber washer - no leaks.

I'd probably use a sealant though myself.