>>> >Is clear nail polish (apparently composed of two kinds of acetate and
>>> >solvent) acceptable as coil dope?
>>NOPE ... The solvent is acetone, highly flammable and toxic
>>The thing you could do, however, is looking at your local library for
>>some real olden radio builder's book. I was amazed, how old some of the
>>stuff is, they have at my local library. In those real old books, you
>>might find some recipes for what you need.
>>. . .
>Coil dope is typically made by dissolving polystyrene in acetone, so "real"
>coil dope is also highly flammable and toxic until it dries. You can make
>it yourself quite easily with styrofoam and acetone from the paint store,
>but do handle it and the acetone carefully. As Siegfried said, it's very
>I never have figured out how applying coil dope would improve a coil. The
>best quality dope will degrade the Q by decreasing the apparent inductance
>due to increased capacitance. Many other materials used for dope will
>introduce loss as well. Maybe someone could enlighten me.
>Roy Lewallen, W7EL
I do not think that the "dope" is to improve any quality of the coil,
but, instead, just to hold the wires in place. If the wires are not
"fixxed" then the L can varry, especialy with any sort of mechanical
shock or vibration. The dope could also keep water off the wires.
I had some dew ruin a nice home made vfo when the litz wire got wet.