On Mon, 09 Feb 2009 16:47:15 GMT, "Spin"
wrote:

I read that old 78 LP's broken into pieces & mixed with a particular solvent
was used as coil dope. Does anybody remember which solvent was used & how
affective it was?

Coil dope can be made from polystyrene packing peanuts dissolved in
acetone. Q-Dope is some kind of cellulose polymer broken down in the
same solvents. If you're planning on making your own, it does take
several days and plenty of agitation to produce a suitable sticky
mess.

The very old 78 rpm records were originally made from Bakelite, which
is quite resistant to chlorinated hydrocarbon solvents. During WWII,
Vinyl records appeared as a substitute for Bakelite. It's easy to
tell the difference. Bakelite is thermosetting plastic and is
unaffected by acetone. Vinyl is thermoplastic and is softened by
acetone.

My guess is that whomever suggested dissolving records wanted to trick
you into breaking your 78 rpm records. (Note: I'm sloooooly
transcribbling my record collection to various digital formats).

You don't state what you're trying to accomplish. If it's cleaning
the Q-Dope off old coils, acetone softens it nicely. Wipe clean and
you're done.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann wrote:
Coil dope can be made from polystyrene packing peanuts dissolved in
acetone.

Beware; this produces significant quantities of styrene monomer,
a known carcinogen.

Clifford Heath wrote:
Jeff Liebermann wrote:
Coil dope can be made from polystyrene packing peanuts dissolved in
acetone.

Beware; this produces significant quantities of styrene monomer,
a known carcinogen.
only in Canadian rats

On Tue, 10 Feb 2009 10:09:17 +1100, Clifford Heath
wrote:

Jeff Liebermann wrote:
Coil dope can be made from polystyrene packing peanuts dissolved in
acetone.

Beware; this produces significant quantities of styrene monomer,
a known carcinogen.

That seems to be debatable:
http://www.styrenemonomer.org/3.5.html
Of course, that comes from the Styrene Products Association, which
might be slightly biased.



--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com
# http://www.LearnByDestroying.com AE6KS

Jim Higgins wrote:
On Tue, 10 Feb 2009 10:09:17 +1100, Clifford Heath
Beware; this produces significant quantities of styrene monomer,
a known carcinogen.
No it doesn't. It's purely a dissolution process with no chemical
reaction.

Glad to hear it - I forget who scared me off using a batch I made
and held on to, unable to decide how to even dispose of it.