That coil is what is known as resistance wire. It is the same thing (basically) that is used in hair dryers, heaters...things like that and in some cases this wire is used in certain styles of rheostats. When current flows through these types of wire, they resist that current much more than normal wire does. This makes the wire get hot and that's why it is encased in ceramic. The ceramic housing keeps the wire from heating other things to the point of danger. So, to answer your question about epoxy, the correct response is: maybe and maybe not. It all depends on how hot the coil gets and how tolerant of heat your epoxy is. Maybe you folks recall when I was working on the fuel gauge sending units. Actually I still am, but that story is a slowly developing one. The same wire is used and the reason it presents no danger in the fuel tank is that only a tiny bit of electricity is fed through it. In the headlight switch, more electricity is fed through and that's why the electrical engineers (and the people in other countries who have copied these switches) use a non-combustible material to hold those coils. The wiper which wipes across the coil connects different points of the coil and that's what makes the bulbs dim or bright...the different points of resistance or lack thereof. If I were to use epoxy, I'd use the original JB Weld. It can withstand 500 degrees F on a fairly constant basis and 600 degrees F for very brief exposures. Good luck.
