" wrote in message
...
On Feb 13, 7:41 pm, "Richard Knoppow"
wrote:
At some time in the recent past there was a discussion
in this or the antique radio group about coil dope. As a
result I tried making some. While it appears to be still
available its hard to find.
What I did was to dissolve polyfoam shipping material
in a mixture of MEK and xylol. I chose these two solvents
because both were listed on the lable of some old
commercial
coil dope.
The result is that the stuff works fine. The solvent
will dissolve an amazing amount of the polyfoam, probably
because its mostly air. After I got the stuff to a good
honey-like consistency I tried it. It dries hard in about
ten minutes. Polyfoam is polystyrene which has excellent
dielectric properties. This is what the commercial coil
dopes were made of.
Both solvents are available from hardware or paint
stores and are cheap. The polyfoam can come from styrofoam
cups but shipping material is the same stuff and is often
just tossed away. All that matters is that its clean.

--
Richard Knoppow
Los Angeles
WB6KBL


Dissolve the polyfoam in gasoline and what do you get?
Napalm!

Paul, KD7HB

A helpful hint:-) I thought it was soap but I've never
seriously wanted to make any napalm.



--
Richard Knoppow
Los Angeles
WB6KBL

"Richard Knoppow" wrote in message
news

" wrote in message
...
On Feb 13, 7:41 pm, "Richard Knoppow"
wrote:
At some time in the recent past there was a discussion
in this or the antique radio group about coil dope. As a
result I tried making some. While it appears to be still
available its hard to find.
What I did was to dissolve polyfoam shipping material
in a mixture of MEK and xylol. I chose these two solvents
because both were listed on the lable of some old
commercial
coil dope.
The result is that the stuff works fine. The solvent
will dissolve an amazing amount of the polyfoam, probably
because its mostly air. After I got the stuff to a good
honey-like consistency I tried it. It dries hard in about
ten minutes. Polyfoam is polystyrene which has excellent
dielectric properties. This is what the commercial coil
dopes were made of.
Both solvents are available from hardware or paint
stores and are cheap. The polyfoam can come from
styrofoam
cups but shipping material is the same stuff and is often
just tossed away. All that matters is that its clean.

--
Richard Knoppow
Los Angeles
WB6KBL


Dissolve the polyfoam in gasoline and what do you get?
Napalm!

Paul, KD7HB

A helpful hint:-) I thought it was soap but I've
never seriously wanted to make any napalm.


Turns out we are both right. Modern napalm has
polystyrene in it, the original used a sort of metallic soap
as the thickening agent. See:

http://en.wikipedia.org/wiki/Napalm

I still have no desire to make any.

--
Richard Knoppow
Los Angeles
WB6KBL