Re: [ARSCLIST] Acetate disc sleeves

[Eric Jacobs <ericj@xxxxxxxxxxxxxxxxxxx>]

Brandon,

I wholeheartedly agree.  I came to the same conclusion, although via
perhaps a more lengthy thought process.  I really wanted a deeper
understanding of all the degradation mechanisms in play to ensure
that our intuitive response was also supported scientifically.  I
think everyone in this discussion has come to the same intuitive
conclusion, although in some cases the underlying reasoning may
not have been altogether correct.

Eric


-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:ARSCLIST@xxxxxxx]On Behalf Of Brandon Burke
Sent: Wednesday, August 03, 2005 10:22 AM
To: ARSCLIST@xxxxxxxxxxxx
Subject: Re: [ARSCLIST] Acetate disc sleeves


Eric,

You know... The more I think about it, the more I'm convinced that
"sealing" the disc in it's housing -- what one would essentially be doing
in this case -- is a really a bad idea.

We already talked about micro-environments on Monday but I'll say again
that sealing the disc within its housing allows off-gassing and other
byproducts of degradation to compound this problem -- perhaps even
exponentially!  It also seems to me that if the discs are stored at
reasonable archival conditions (let's say <50% RH) there's less of a need
to keep moisture out.

Echoing what Richard said earlier today, I think I'd prefer to have at
least some airflow within these housings.

Brandon



At 09:21 AM 8/3/2005, you wrote:
>Thank you very much.  At $4.10 per sleeve in small quantities
>for 10-inch discs, these Metal Edge sleeves are substantially
>more (by 4x) than the next most expensive sleeve.  Even the
>best possible pricing for this sleeve is $3.20 per sleeve in
>large quantities.  Cost aside, they look like a good alternative.
>
>We are looking at the sleeves from Conservation Resources,
>which are 4 layers (paper/polyethylene/foil/polyethylene) and
>about $0.87 per sleeve in small quantities.  These sleeves are
>very close to what Pickett and Lemcoe suggest in their landmark
>1959 work "Preservation and Storage of Sound Recordings".  The
>sleeve lacks the window, but the foil and polyethylene provide
>a vapor barrier and a smooth inorganic surface against the
>record.  You can see them here:
>
>http://www.conservationresources.com/Main/section_6/section6_07.htm
>
>These look like a great sleeve for shellacs or vinyl, but I'm
>not sure about using these for acetates.
>
>If breathability is important, then for 16-inch discs, these
>sleeves/envelopes look very attractive from:
>
>http://www.conservationresources.com/Main/section_6/section6_09.htm
>
>Although they lack a window and are basically folder stock (lignin
>free), the seams are on the outside and there is a flap to
>further protect against dust.
>
>For 10-inch discs, there are plain polyethylene sleeves from Bags
>Unlimited.  These are 3-mil thick (good), but they don't seem to
>offer much mechanical protection of the disk:
>
>http://www.bagsunlimited.com/cart/browse.asp?subcat=41
>
>The real question for me is the importance of air circulation in
>the sleeve versus the need for a vapor barrier against moisture.
>These two needs are diametrically opposed.  One of these is the
>lesser of two evils, but I don't know which one (lack of air
>circulation, or presence of moisture).
>
>Others on this list have suggested that perhaps acetate discs
>behave in a manner similar to nitrate film, and that air
>circulation may be the priority.  However, I want to also hear
>from those with long-term acetate/nitrocellulose discs in their
>collection.
>
>It would be interesting to know more about what went into the
>thinking of the LC-designed sleeve.  Is the LC-designed sleeve
>targetted at all discs, or does it particularly take acetates
>into account?
>
>Thanks for the fast response - the ARSC List has been very
>quiet this Summer.
>
>Eric Jacobs
>The Audio Archive
>
>
>
>-----Original Message-----
>From: Association for Recorded Sound Discussion List
>[mailto:ARSCLIST@xxxxxxx]On Behalf Of Sam Brylawski
>Sent: Wednesday, August 03, 2005 6:00 AM
>To: ARSCLIST@xxxxxxxxxxxx
>Subject: Re: [ARSCLIST] Acetate disc sleeves
>
>
>Hi Eric,
>
>LC developed a nice disc sleeve several years ago. Metal Edge won the
>contract to mfg it. The link to their catalog is:
>
>http://www.metaledgeinc.com/Products.tpl?cart=11230736142091320&id1=25&id2=
9
>98&startat=1&--woSECTIONSdatarq=998&--SECTIONSword=ww&ran=5546
>
>If that doesn't work, go to metaledgeinc.com and look under
>"Phonograph Record and Film/Audio Reeel Storage: Archival Quality
>Phonograph Record Storage Sleeve.
>
>The sleeve is actually two, an acid-free board with center hole, and a
>loose-fitting Mylar outer sleeve.
>
>Sam
>
>On 8/2/05, Eric Jacobs <ericj@xxxxxxxxxxxxxxxxxxx> wrote:
> > What are your preferred sleeves for storing acetate (nitrocellulose)
>discs?
> >
> > Here's the debate (per "Preservation and Storage of Sound Recordings",
> > Pickett and Lemcoe, 1959):
> >
> > 1.  The deterioration of nitrocellulose is accelerated by moisture
> > 2.  The deterioration of nitrocellulose is accelerated by lack of air
> > circulation
> >
> > Which is the lesser evil - moisture or air circulation?
> >
> > Assume that the storage environment is approximately 70F and 50% RH and
> > stable, and that the records may potentially remain undisturbed for many
> > decades:
> >
> > A.  Does the disc benefit from the additional protection of a vapor
>barrier
> > as part of the envelope?  Or does the vapor barrier prevent adequate air
> > circulation?  For example, a polyethylene sleeve, or a multi-layer
> > paper/poly/foil/poly sleeve.
> >
> > B.  Or are you better off with a 10-point folder paper type envelope
which
> > will breathe better than a sleeve with a vapor barrier?
> >
> > C.  What about paper type sleeves with center cut-outs for viewing the
> > label?  They provide good air circulation, but provide no protection
>against
> > contaminants or moisture.
> >
> > Now that our collection has been properly cleaned and transferred
(16-inch
> > audiodiscs), we would like to store it as well as possible, including
the
> > selection of an optimal sleeve.
> >
> > Eric Jacobs
> > The Audio Archive
> >

_______________________________________
Brandon Burke
Archival Specialist
Hoover Institution Archives
Stanford University
Stanford, CA 94305-6010
voice: 650.724.9711
fax: 650.725.3445
email: burke@xxxxxxxxxxxxxxxxxxx