What would be the preferred wax to use after rewinding a coil? I have beeswax but is there another type that might prove better against heat/moisture?

Beeswax is fine, and reversable should you need to remove a turn or two or look for a break. Plain uncolored beeswax candle is OK.

I re-wound an oscillator coil for a Grunow. I dunked it in melted bees wax and pulled a vacuum over it. After much bubbling the vacuum was released and the coil allowed to cool. When the coil was cold it was dipped again to get a thick coating, worked perfectly...

Chas

Chas went through an interesting procedure. A lot of us can't draw a vacuum etc. His coil worked perfectly but it will still operate without the wax coating.

Thanks for the replies. I was tossing around the idea of using parrafin but now I see it has a lower melting point than beeswax (120 compared to 140) so I'll coat it with the bees.

If the coil is placed in the cup with melted bees wax and left to soak for 1/2 an hour or so, most of the moisture should be driven off without using a vacuum. Let the coil cool then re-dip, quickly, to get the thick surface like a factory job