16 Jan
2013
16 Jan
'13
4:23 a.m.
Terry, the retr0bright process (and Merlin) also
mentiones "The permanent
fix it is to coat it with clear satin acrylic lacquer to seal the surface
off from the air." Basically stating the process can eventuall reverse
itself it you don't and sealing it with an anti-UV laquer provides "No
oxygen, no oxidation." It's a very light acrylic, usually used for
preserving paintings/drawings/etc.
I've also seen some people mention using Armorall
spray or 303 Aerospace
Protectant Wipes
Yes, this was the current thinking. But given the yellowing seemed to
occur with such little light exposure, I wonder if this needs
revisiting?
The original damage from light causes degraded or free bromides
throughout the case from the fire retardants hence yellowing. Merlin
says in the Wiki that Retr0Bright only fixes these in the surface
layer and that this "cleaned" layer can re-yellow with exposure to UV.
Fair enough. However elsewhere in the wiki he also says these
bromides can migrate fairly freely through the polymer. Presumably
they don't need light to do this. I imagine migration is probably
accelerated in hot conditions.
My hypothesis as to why re-yellowing occurred in my machines with such
little exposure to light was that deeper pre-existing bromines from
the original damage (not touched by Retr0Bright) migrated to the top
"cleaned" layer and within a few years yellowed the surface again.
If this hypothesis is correct then a UV sealant will not protect the
case. Or any sealant maybe. Unless pre-formed bromides from previous
light damage can be stopped from migrating to the surface (and I don't
know how you would do that) Retr0Bright is only ever going to be
temporary.
Anyway. I have sent Merlin a PM through the VCF to see what his
thoughts are on it. It may only be proved by experimentation but the
hypotheses seems to fit with what happened. It also fits with what is
said about the yellowing process in the Retr0Bits Wiki.
Terry (Tez)