[Trevor]

On 24/06/2015 10:59 PM, Scott Dorsey wrote:
In article , Trevor wrote:
On 24/06/2015 12:35 AM, Mike Rivers wrote:
On 6/23/2015 6:44 AM, Trevor wrote:
vinyl records will have long turned into sludge before 5,000 years,
you'd be better off keeping the metal masters.

Maybe they will, maybe they won't. People who complain about landfills
say that they have things in them that won't deteriorate for centuries,
so who knows whether they'll deteriorate in 5,000 years.

Almost anyone with real chemistry knowledge I imagine. Characteristics
of various plastics are fairly well known. Do NOT think that just
because some plastics last a long time, all of them might. Even non
chemists know that!

Unfortunately they get proven wrong all the time. Witness sticky shed
with the new formulation that was supposed to last so much longer.
Witness the Kodak "low fade" print stock that faded faster than the
older stock. Until a material has actually been around for 5,000 years
it's hard to be absolutely sure how they will react to 5,000 years of aging.

You've got it ass about. We can often be pretty sure what WON'T last
5000 years, even if we can't be sure what will.


Metal masters are nice to keep, but there are so few of them compared to
the number of pressings. Metal masters aren't all that common (most are
cut on lacquer),

Which are then plated.

If you keep the lacquers, the plasticizer from the lacquer outgasses and the
lacquer layer shrinks and separates from the base.

If you keep the metal, it can corrode (although cosmolene and the like can
help a whole lot).

True, to be really safe you need to do what NASA did and use a solid
gold disk! :-)

Trevor.