Brittle plastic

Chuck Guzis cclist at
Wed Sep 2 15:46:01 CDT 2020

On 9/2/20 12:02 PM, Rico Pajarola via cctalk wrote:
> I have a friend who is a Materials Science Technologist and specializes in
> injection molded plastics. So... basically the same thing that's in
> computer cases (even though he doesn't deal with computer cases). I grilled
> him at length on this topic, and he insisted that the brittleness with age
> (and UV light) is expected and irreversible. Basically, the plastic
> softeners are off-gassing, and there's no way to put them back in.
> I'm still hoping for a happier second opinion, though I'm not holding my
> breath.
> In my experience, brittleness varies wildly and goes from "no big deal" to
> "crumbles if you blow at it", even for otherwise identical machines. I
> recently acquired a Japanese Ultra 1 clone, and the back was smashed in
> shipping, and crumbled into a thousand pieces not even large enough to glue
> back together. Luckily the front only had a single crack that could be
> glued back together.

It's a very well-known problem among the museum conservation crowd--and
with no practical solution.

For a discussion, WikiPedia is pretty informative:

The Getty has a few papers on the subject:

Sadly, there's no good answer, other than making a new duplicate.  Apple
had some really awful plastics in the 80s that would spontaneously
destruct.  I doubt that they are alone in that.

Give me painted high-density structural foam any day.


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