it can also be chemicals which leach out from the interior of the tape pack
onto the tape pack surface. i use Pellon cloth to clean such tapes at
library wind speeds. no problem in playback. wiping it just removes it so
to not build up on tape guides and heads....
On Tue, Jul 1, 2014 at 2:46 PM, Tom Fine <[log in to unmask]>
> Hi Karl:
> I am guessing it's mold (mould to some). I would gently wipe both sides of
> the tape-pack with 99% or higher isopropynol, using a low-lint cloth (and
> frequently changing the surface area touching the tape packs), then
> re-shell the cassettes. My bet is that they'll then playback just fine.
> If bychance they don't play well, stiction to the point of auto-shutoff
> for instance, bake them like a reel tape -- 4+ hours. I just had this work
> very well for me on two sticky tapes that absolutely would not play in any
> machine until they were baked, then they played just fine. I admit that two
> cassettes is not enough of a sample to draw any conclusions about baking,
> but it definitely worked in these two cases.
> As for mold (mould) on tapes, I've seen that on cassettes and videotapes
> before. Carefully wiping the tape pack seems to do the trick. If you want
> to be extra careful, clean the heads after each side plays. My experience
> with no 1000+ cassette transfers is that they are always pretty darn hearty
> as far as magnetic media goes. If only more people recorded them with more
> skill, but that's a whole other story ...
> -- Tom Fine
> ----- Original Message ----- From: "Karl Fitzke" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Tuesday, July 01, 2014 1:25 PM
> Subject: [ARSCLIST] White Audio Cassette Contaminant
> Anyone care to venture any guesses on these photos and what to do about
>> it? For the time being, I will hold my tongue and not prejudice the jury.
>> June 1987 recording on 3M/Scotch AVX90 cassette. There's eight more where
>> this one came from, recorded from 2nd through 3rd quarter of 1987, and two
>> Scotch AVM cassettes recorded in early 1988, with similar but significantly
>> less on edge of tape.
>> Karl Fitzke
>> Audio Engineer
>> Macaulay Library
>> Cornell Lab of Ornithology
>> 159 Sapsucker Woods Road
>> Ithaca, NY 14850
>> [log in to unmask]
>> Our Mission:
>> To interpret and conserve the Earth's biological diversity through
>> research, education, and citizen science focused on birds.