Thread: Coil Dope
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Old February 11th 09, 03:39 AM posted to rec.radio.amateur.antenna
Dr. Barry L. Ornitz[_2_] Dr. Barry L. Ornitz[_2_] is offline
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First recorded activity by RadioBanter: Jan 2009
Posts: 11
Default Coil Dope

"JIMMIE" wrote in message
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I believe what you are describing is Duco cement the kind that I
used to use to build model cars.
Is that stuff still around? I think they took it off the market
because of the glue huffers. If it is still around it should make
excellent coil dope.


Duco Cement is made by the Permatex division of ITW/Devcon. It has not
been taken off the market, but in some communities its sale is restricted
to keep it away from children.

Duco Cement is cellulose nitrate dissolved in acetone. It is plasticized
by a small amount of camphor (probably for historic reasons, camphor was
the plasticizer used in celluloid and pyroxylin around the turn of the 20th
century).

As I stated in the post you quoted, cellulose nitrate is far from the best
radio frequency insulator. Fingernail polish performs slightly better as
an RF insulator but polyvinyl chloride is worse. I still recommend General
Cement commercial Q-dope which is polystyrene dissolved in toluene or
methyl-ethyl-ketone (GC has changed their formulation). You can make your
own inexpensively by dissolving Styrofoam shipping "peanuts" in toluene.
methyl-ethyl-ketone, or acetone. Of these three solvents, acetone is the
safest. Home Depot used to sell all three solvents in the past, but sadly
there is no store near me where I now live.

--
73, Dr. Barry L. Ornitz WA4VZQ

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