transducer kit oil?

Castor oil is what Seafarer recommended in their day. It is what is in mine. Never needed topping up in thirty years!
 
I used Johnson baby oil 3 years ago and still works perfectly, and leaves your hands smelling beautiful afterwards.
 
I was advised by everyone at the yard to use Castor Oil. But, I cannot get the transducer out of the hull fitting. My concern is the shape of the face of the transducer and is it capable of trapping a bubble?
 
Top