SGI Indy discoloration

liquidkoshman

New member
Dec 31, 2022
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Czech Republic
Hi all,
I'm new here and apologize in advance if my question was answered before (likely), my search came up empty.
I recently acquired an Indy (my first SGI wooho, one dream coming true!). It came complete with keyboard, mouse, cam, even the 21" trinitron monitor that I had to leave unfortunately as I have no place to put that. While it seems functionally fine, everything is pretty badly yellowed/discolored.
For the accessories I would assume I can use the usual retrobrite solution as for other retro computers. But for the machine itself I'm unsure - the discoloration is pretty bad and you can easily see where the monitor stood as that square is pristine still unlike the rest of the top. So due to the color, material etc. of the case not being the regular greyish ABS plastic can the same solution be used or would you recommend something else?

Thank you.

Cheers,
Radim
 
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flexion

Active member
Sep 23, 2020
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Hi and welcome!
One of my Indys also has an ugly border from the monitor stand. I carefully tried with some hydrogen peroxide (which worked GREAT on the grey Indy Cam), but I couldn't get rid of the discoloration completely. Also I didn't want to risk to make it worse and did only one session.
"Retro-brighting" is just temporary, the yellow will come back. Maybe it's easier to just keep looking for another Indy in better condition with less UV exposure, as there are plenty of it for sale and they're easy to ship compared to other models.
 

liquidkoshman

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Dec 31, 2022
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Thanks, I was afraid that might be the case...
I wonder regarding the temporary nature of retro-brighting - do you mean the effect will not last long and the yellowing will return sooner than it actually happened in the first place when these things were new? Also if not left in direct sunlight will that prevent/slow down the process or will it yellow again no matter what now that it was already yellow once? I hope it makes sense:) just wondering about your personal experience
 

flexion

Active member
Sep 23, 2020
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Switzerland
From my experience it does not last long. I "retrobrighted" this Indycam two or three years ago. It was really yellow except the part where the lens lid was in closed state, so the gray/yellow difference was pretty heavy when you opened the lid.
The color difference was 99.99% gone after retrobright treatment. It looked like new, no color difference with opened lid anymore.

Meanwhile the color difference around the lid is slightly visible again. Not as bad as before the treatment, but the yellow is slowly coming back. The camera was stored in a box without exposure to UV. I couldn't find a "before" picture, only one after treatment:

after_retrobright.jpg
 

liquidkoshman

New member
Dec 31, 2022
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Czech Republic
Thank you. So the yellowing comes back even if the item is not exposed to UV again at all, interesting. I have to decide whether it's worth it to retro-bright then...
As for the case I guess finding a better one and replacing it is my only option.
 

nuclear

Member
Jun 3, 2020
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nuclear.mutantstargoat.com
Yes, but if you keep it out of sunlight, it takes many years to revert back to extreme yellowing.

I've retrobrighted an original gameboy 4 years ago: and while it has become visibly a bit more cream-colored now, it's nowhere near the yellow that it was before.

So if the yellowing is too much and annoys you, give it a try, you might end up having an acceptable result for the next decade, before it becomes annoying again.

But I don't know, I don't mind yellowing very much anyway. I've left most of my old hardware as is, I don't usually bother with retrobrighting. The only other thing I tried it on, is the spacebar of my SGI keyboard ( ), and it has reverted also, again not as it was, but visibly yellowed next to the rest of the keycaps.
 

liquidkoshman

New member
Dec 31, 2022
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Czech Republic
Thanks for your perspective :) that doesn't so bad
I'm personally not really bothered by the yellowing on most of my classic gray retro machines (say Amigas), but it looks really ugly to me on the SGI granite keyboard etc.
I will see if it bothers me enough to go through the process :)
 

Elf

Storybook
Feb 4, 2019
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Western United States
Painting it over is also another option that can have decent results if what is underneath truly looks bad, although the color flecks would be difficult to duplicate.
 

CRaven

New member
Sep 25, 2022
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Another vote for painting.

Actually it's one of the projects I have on my queue. My Indy is very discoloured actually is green now, sigh, I used the retrobright method but it only lasted a few weeks, then it returned to its crappy state. So my plan B is to paint it, I went to a store that fill cans by catalogue and we matched the supposed Indy blue. The granite dots effect I'm thinking of 2 options, using an airbrush with very low pressure at a distance or the slow method making one by one. The final pass would be a 2K satin varnish.
 
Last edited:

DirtPiper

New member
Jan 17, 2023
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The yellowing process is a form of oxidation and only occurs when the plastic is in direct contact to air - if you were to clear-coat the plastics immediately after retr0brighting them the yellowing probably would not return, even in the presence of UV or heat (peeling the stickers off of any old yellowed PC will reveal a white patch for this reason). Just my two cents!
 

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