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The very old 78 rpm records were originally made from Bakelite, which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