[Info-vax] what color?

[MetaEd]

On Aug 16, 1:30 pm, Dennis Grevenstein <dennis.grevenst... at gmail.com>
wrote:
> The 3100 series has a case made out of metal.
> Also, using chemicals to brighten up a plastic case, is much more
> like turning a brunnette into a blonde, rather than restoring the
> true color.

With regard to restoring plastic cases, which is evidently not the
situation in the OP:

The restoration that I posted above is not like turning a brunette
into a blonde. It does actually restore the true color. It's dramatic
to the point of seeming miraculous.

It was common practice to make plastic cases fire resistant by adding
poly brominated diphenyl ethers with the ABS plastic before molding.
The additive was colorless. However, it readily broke down when
exposed to ultraviolet --- and you get a lot of UV from fluorescent
lighting as well as sunlight, so this was a common problem. The
resulting bromine free radicals gave a yellow or brown color to the
plastic.

The restoration involves binding a hydrogen to each bromine free
radical near the surface of the case, neatly reversing the color
change.

Afterward, you can either repeat the treatment from time to time, or
else protect the case from UV (as for example with a UV resistant
clear laquer).