Re: [ARSCLIST] Memorex CDs - long reply on CD methodology

[Mike Richter <mrichter@xxxxxxx>]

steven c wrote:

> I was thinking of pressed discs...or commercial CD's. It seems reasonable
> that recordable discs wouldn't be "built" in such a way that their
> content could be in any way renewed.
>
> So, on a regular CD (not recordable)...could the protective plastic
> layer be removed without affecting the pressed surface (which I
> assume would be underneath the protective layer...right?). Or,
> do the two plastics bond together in such a way that one cannot
> be separated from the other?
>
> And...how thick is the acrylic "overcoat?"
>
> Steven C. Barr

The acrylic layer is thin and theoretically could be dissolved away, 
leaving the metal untouched. I say 'theortetically' because I doubt that 
that would be doable in practice - but it may not matter since the 
information is in the shape of the underlying plastic. Then the metal 
would have to be dissolved to leave the pressed polycarbonate surface 
for replating. If the polycarbonate is not disturbed in that process, 
replating should be straightforward though quite expensive.

There is an effective limit to the thickness of the overcoating since 
there's a maximum thickness of the disc (to work in slot drives) and a 
tightly constrained distance from the bottom of the polycarbonate to the 
overlying metal. Unfortunately, I don't know that number; fortunately, 
it doesn't much matter.

Mike
--
mrichter@xxxxxxx
http://www.mrichter.com/