RF coil dope

[Peter Howard]

Here's a quick one. What do you use to secure the wire of HF inductors,
whether wound on cylindrical formers or on iron powder toroids. I have
googled the topic and read lots of the hits. Polystyrene dissolved in
acetone, toluene or xylene seems to be popular.

In the past I have used tarzans grip, nail varnish, genuine shellac made of
flakes in methylated spirit, model aircraft styrene cement and PCB conformal
coating from s spraycan. The PCB coating was neat and easy to apply but I
wonder about its dialectric properties at radio frequencies. I'd think it
would be fine but I've thought wrong before. Americans favour Duco cement
but that brand-name of solvent based nitrocellulose glue seems not to exist
in Oz.
I have just tried dissolving foam cups in acetone but only produced a white
mass that was not very adhesive. Maybe my cups aren't really polystyrene.

So what's a good coil dope, preferably available off the shelf in Australia?
PH

 

[Baron]

Peter Howard Inscribed thus:

Here's a quick one. What do you use to secure the wire of HF
inductors, whether wound on cylindrical formers or on iron powder
toroids. I have googled the topic and read lots of the hits.
Polystyrene dissolved in acetone, toluene or xylene seems to be
popular.

So what's a good coil dope, preferably available off the shelf in
Australia? PH

I've used clear nail varnish for years, even at 10ghz on copper and
brass, where i've used it to stop tarnishing.

--
Best Regards:
Baron.

 

[Clifford Heath]

On 24/08/13 18:41, Peter Howard wrote:
> Polystyrene dissolved in acetone, toluene or xylene seems to be popular.

Dissolved polystyrene contains styrene monomer, which is dangerous, c.f.
wikipedia:

"Styrene is largely metabolized into styrene oxide in humans, resulting
from oxidation by cytochrome P450. Styrene oxide is considered toxic,
mutagenic, and possibly carcinogenic"

Care!