when installing covers, do you need to put a bit of wax in between the top of the coils and the top inside surface of the cover? or do you just slip them on and solder two small tacks to the base plate, no wax needed ?
There are different takes. If you want to make it (nearly) permanetly i would solder, since it make a better grounding of the cover.
I have done the waxing connection and did also taping (wanted to fool around with magnets). This also works great for a period of time (some years), but then the tape crumbles after years and the wax breaks - especially if you use 100% parafin wax.