27 Jul
2010
27 Jul
'10
11:13 p.m.
Well, the process was first introduced in January of '09, so the year
test would have been passed on those done in the first six months.
The only thing that's been reported so far is in some cases is a
reversal of the whitening process, with some of the treatments
starting to yellow again. Merlin (the originator) said:
"Retr0bright reverses the yellowing process, it's not a permanent
cure. If the surface of the plastic is still open to the air, it will
yellow again, as the bromine free radical reaction is reversible.
The permanent fix it is to coat it with clear satin acrylic lacquer to
seal the surface off from the air. No oxygen, no oxidation; simple,
really."
It's available in hobby shops (in spray form) and usually used my
modelers and the like to protect paint, it's not a heavy varnish or
something similar.
As far as blooming, that usually occurs in areas where the spreadable
version of the mixture was left on for to long or allowed to dry. I
have not heard of it happening when submerging in the pure liquid
version.
In other cases, some people have decided not to use the actual mixture
and simply use the peroxide portion as a shortcut which has caused
blooming. The process will also caused blooming on dark colored
plastic, and as such is only for white/tan colored plastics.
I've personally used it on an Apple III, and white Bally Computer case
with stellar results, which you can see here:
http://www.atariage.com/forums/topic/138244-how-to-remove-yellowing-from-an…
That entire thread is also full of further discussion, testimony (and
pictures) as well as comments by some who have had blooming as result
of one of the reasons mentioned above.
Marty
On Tue, Jul 27, 2010 at 3:30 PM, Teo Zenios <teoz at neo.rr.com> wrote:
----- Original Message ----- From: "Fred Cisin" <cisin at xenosoft.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Sent: Tuesday, July 27, 2010 4:09 PM
Subject: Re: retr0brite not so right?
Depends on what you are talking about.
If the concentrations are enough to cause visible damage in 2 hours then I
would think that 1 hours use would cause some damage that might take a while
to show up. You also have to assume that the chemicals are being used up as
the process is going meaning the concentration is slowly dropping while it
is sitting, so damage can be going on the second the plastic is being
dropped in. Plastic soaks up chemicals that stay even when you rinse them
out (I can smell pineapple in a plastic container long after it has been
washed and dried), which is why you never store water in anything that seen
chemicals. So I can see some reactions still going on inside the plastic
(depending on its density) even after you have cleaned it off.
If you mean X concentration will cause damage then .5X concentration will
cause half that damage, then no.
Long term damage could be as simple as the plastic decaying from UV ?light
after you leached the UV inhibitor from the surface using retro-bright.
Since everyone mixes up a slightly different batch of
chemicals/concentrations, does different prep work, ?and uses it for varying
lengths of time in different sunlight and heat conditions on all kinds of
plastics (which might have UV inhibitors or none at all depending on the age
and manufacturer) who knows if there will be damage or not either short term
or long term.
Personally if the item is rare and would be worth more "whiter" for a quick
sell, then clean it up. If you are going to keep that same item as a
permanent part of the collection then you might as well wait a few years and
see how this all pans out.
This
appeared on the cbm-hackers list today. Anyone have a thought on it?
The fact that too much will cause damage does NOT mean that half as much
causes half the damage. ?It is far from linear, and there may be
thresholds.
To quote Paracelsus:
Poison is in everything, and no thing is without poison. The dosage makes
it either a poison or a remedy.
Admittedly, Paracelsus was expert on neither computers nor plastics.
--
Grumpy Ol' Fred ? ? cisin at xenosoft.com