i have completely disassembled and painted cases before i have a purple 89se p3 rig, granted it was intended or a different purpose.

cdoublejj wrote:

i have completely disassembled and painted cases before i have a purple 89se p3 rig, granted it was intended or a different purpose.

Pics or it didn't happen! 😜

Retrobrighted my K6-2 System and my father's old 286 Tandon the last few days 😉

I wonder if using 303 Aerospace Protectant will help to prevent yellowing again - it's a UV protection made for plastics (used in boat / automotive industry). It's easy to apply and easy to remove - although that's not necessary because it doesn't alter the color. I recently did retrobright on an old AT case and old Roland speakers and I applied 303, so let's see if it will help. But it will take few years to find out 😀. Also the 303 is not a permanent protection, you will need to reapply it from time to time, but it will probably take months indoors until it disappears from the surface. I think it should because it also partially seals the plastic surface so that less oxygen will "oxidize" the plastic (yellowing isn't just caused by UV, there are multiple factors, it's also caused by oxygen and heat itself. There is a good short article on the yellowing process and it also debunks some myths around it- https://medium.com/@pueojit/a-look-into-the-y … cs-db14b646e0ad).

I've given my retro plastics the 303 treatment but only started doing it about 6 months ago - impossible to know if it will have a positive effect but it can't hurt I don't think.

I use liquid Vanish Oxi Action. I wash the part thoroughly, then coat it with a thick layer of the substance, then wrap it in clear foil and set it in the sun. In strong direct sunlight and heat, plastics can bleach in as little as 3 hours. In weak winter sun it can take up to 24 hours to bleach a part. Powerful UV laps and heat (30-40C) also work well.

I tried the powder version of Vanish Oxi Action as well - wash the parts and put them in a container filled with warm water and Vanish. It works, but a lot slower then coating the parts in liquid vanish.

The advantage of using liquid vanish is speed - but if you're not careful to coat the part uniformly, you might get streaks or the plastic won't bleach uniformly. Using the powder version and submerging the part in water does not have this problem, but it's painfully slow.

I have done retro-brightening of an AcerMate 466d (486 machine) back in 2009 using a mix of water, diluted hydrogen peroxide and Vanish Oxy-Clean powder. The ugly yellowing in plastic case was completely removed and it was restored to its original white/beige color. However, after few years, the case in some parts turned yellow again, sometimes even dark/brown color, so needs another retro-bright. This happened only at portion that was somewhat visible so was accessible to indirect sunlight (reflection from walls, etc.) So it looks like you would need to re-apply retro-bright technique every couple of years, to maintain the original color. I have tried covering the plastic with Armor-All but the results were mixed.

An alternative is to get a case that is not affected by this yellowing - I have IBM Personal Computer 350-P75, which still has its original color and no yellowing whatsoever. Both IBM and Acer cases are placed at the same location (AcerMate lies on top of IBM when stored) so it seems the quality of plastic differs between manufacturers. I have also IBM Personal Computer 300GL, which does seem to be getting slightly yellowish and its plastic is becoming more fragile, so likely they switched to worse plastic type at certain point.

badmojo wrote on 2020-08-01, 22:20:

I've given my retro plastics the 303 treatment but only started doing it about 6 months ago - impossible to know if it will have a positive effect but it can't hurt I don't think.

Any success? 😀 i think here would be more important to protect against the oxygen, the radiation (uv, heat) works just as a catalyst. The retrobright is beaching to release the oxygen, and they will reconnect after a while.

Another issue, the degradeted surface is not the same, as the original one, and the bleached is a third one. The coating probably is designed for the original surface.

arncht wrote on 2022-07-17, 06:39:

Any success?

Well my monitor and PC case are still not yellowed from what I can tell but in saying that neither of them ever were much. The monitor I've had for about 10 years and came NOS in the box, and the case did need a retrobrited initially it wasn't very yellowed to start with.

I'm careful to keep them out of direct sunlight and the room they're in never gets particularly hot.

So my conclusion is - I have no idea 😀 I've seen lots of cases with very yellow drive bay covers and not so yellow everything else, so I guess some plastic yellows more than others. I often see cases that are more yellow on one side which I presume is where direct light was hitting them, so that's definitely a factor too.

Do you reapply every months?

Nar I haven't done it for ages - maybe I should!

badmojo wrote on 2022-07-18, 09:22:

Nar I haven't done it for ages - maybe I should!

They suggest it… but be honest, i wont reapply monthly for ever cases.

I have read about the plastic degradation, they use stabilizers against the oxidation even against the uv and heat. Many molecules are in exited state, and the oxygen is connecting to it, change the plastic properies. The retrobright just remove the connected oxygen, but if you store in the air, it will oxydize the plastic again - the uv and the heat just the catalyst.

Probably this stuff is a stabilizer, do not allow to to attack the surface, but every stabilizer has a useful lifespan.

If it helps, from my experience the plastic's composition is also a big factor. I've used the submersion method in hydrogen peroxide and it works well (in various percentages but normally at 9%), and while being relatively easy it's not guaranteed that it won't marble in some specific cases or that it won't re-yellow again in general. Some examples and results with that method:

1. Mouse and keyboards: I retrobrighted a serial Genius Net Scroll mouse that was very yellowed and unevenly at that. It came out white all around, but after a few months it went towards a consistent and balanced off-white / beige tone, which I'm satisfied with, but shows that it wasn't able to keep within the original color I achieved. I also had a Ps/2 Logitech Access Keyboard with the main body slightly beige instead of white and the keys totally yellowed. After the submersion method the keys were in a kind of chemically burnt white, very unnatural looking and brittle, and just broke as I inserted them in the main body again. The body itself came out perfect and remained white since.

2. PC and CD-ROM front panels: I had bought a P-III PC with a yellowed front panel that had a damaged store sticker, and below it was the original color. After the treatment it came out in the original off-white, perfect and even, turning into a darker beige type of tone with time. As for CD-ROMs, I've did it with Asus and Toshiba front panels, the Asus one was able to stay almost within the original beige, the Toshiba one just returned to the very yellowed state in a month or so.

3. Consoles and controllers: The most problematic ones for me, due to very different plastic compositions between the consoles. The worst one for me was the Dreamcast, mainly the controllers. It has a sturdy off white plastic with a grey back piece, and the latter tends to marble and pale slightly even with a single submersion session. All the DC controllers I retrobrighted returned to a slightly less yellow state with no exception, and with the grey back plastic marbling and slightly turning pale I don't think it was worth it. In comparison, I did the treatment to an XBox 360 controller and it came out like new and remained so ever since. The most curious case is the PSX/Playstation 1 main body. My PSX had a yellow tint in the front half so I went ahead and submerged it. As always I wrapped up the container with some plastic wrap and the bubbles must have pushed the case up, sticking the case to the lower side of the film. This left a very noticeable marbled wave in that spot, ruining the case for me. I did another session which helped but it was still visible. So out of desperation I picked up a hairdryer and tried in spurts to heat up that area so that the plastic's original surface came again to the fore. I knew it didn't work with most plastics but it was worth a shot, and it worked out beautifully, it was as good as new. I ended up doing it to the whole case, and I think that because the plastic resurfaced itself with the heat even if it would re-yellow after the treatment it probably won't happen now, which ended up being a blessing in disguise. This hairdryer/heat gun trick normally works better in inner and outter car plastics, and the PSX is the only other example I've found this to work (it doesn't work with the Dreamcast, I've tried). You can easily renew the case this way, front buttons and all, but don't overdo it in the same place for more than 2 seconds, and keep moving the hairdryer at some distance along the case - a heat gun is definitely overkill for this and a recipe for disaster, so don't use it. I didn't try this with the PSX controllers or memory cards so I couldn't say. The Dreamcast plastic is sturdier than the PSX, but the PSX reacts much better to the submersion treatment.

4. Silicone cases: The simplest ones, I have 2 silicone cases for my MP3 and MP4. Submerge them and even without sunlight they will de-yellow overnight. I did it more than once over the years and they're always in shape.

So after all these experiences what do I recommend? Well... Of all the methods I've seen the submersion one is definitely the most widely accessible. Most countries will sell up to 9% Hydrogen Peroxide to the public, more than enough to treat plastics effectively. Put the stuff in a container, cover with some plastic wrap, leave it in sunlight and that's it. But with the chemical reaction the bubbles will make stuff float to the top, so you have to put on small weights or find another way to make it stick to the bottom of the container. And with weights you create shadows which may in some specific cases (too hot temperatures or very intense sun rays directly on the case in noon sunlight) create problems to even out the finish along the plastics (always the different plastics composition and resistance issue). So like the cream method it also has its risks, as we live in different countries with different sunlight patterns and temperatures.

In conclusion, I would advise people who are on the fence about it to do it only in instances where the plastic has a very uneven yellowing all around as it will definitely even out everything, or even in cases with very extreme all around yellowing, where you would find any final result to be "still better" than it was originally. I say this because the type and composition of plastics differ way too much and it's impossible to predict results, and at best on average what you will probably get is ultimately go down a few shades of yellow with an even color all around, which can be fine too. Is this enough for you to risk it? It's up to you. In most cases I've learned that it's not worth it. Just clean up your stuff and keep it from direct sunlight, and barring extreme cases, the rest is what it is.

Ideally I think that the most trouble free method would be to get some UV lights and leave them on with the stuff in an empty container for however it takes, probably a week. If I get across an extreme case of yellowing in the future I will definitely try this, using only UV light removes marbling and chemical reactions out of the equation, so it may be worth it. Would it re-yellow again anyway? Probably. Hope this helps someone, good luck

Hmm… maybe we should join to this. Basically our goal is the same, save the old computers for the future.

https://popart-highlights.mnhn.fr/

tried many times

after a year yellow came back, left it yellow, too much of pain to do and it will get yellow again

arncht wrote on 2022-07-17, 06:39:

badmojo wrote on 2020-08-01, 22:20:

I've given my retro plastics the 303 treatment but only started doing it about 6 months ago - impossible to know if it will have a positive effect but it can't hurt I don't think.

Any success? 😀 i think here would be more important to protect against the oxygen, the radiation (uv, heat) works just as a catalyst. The retrobright is beaching to release the oxygen, and they will reconnect after a while.

Retrobrighted plastic treated with 303 (several layers) and stored for 2.5 years inside a room ( ~22C) and covered with black plastic yellowed again. I am now doing another test with Renassaince Wax (https://en.m.wikipedia.org/wiki/Renaissance_Wax) which should be better at blocking oxygen.
There is a good explanation of the yellowing here: https://deskthority.net/viewtopic.php?p=228424#p228424 it seems that once the plastic is damaged by UV then the yellowing will continue even without exposure to UV.

There was already one attempt to test the wax by this guy: https://www.jackenhack.com/retr0bright-will-it-last/, unfortunately he didn’t finish it.

Killian wrote on 2023-02-07, 20:29:

Retrobrighted plastic treated with 303 (several layers) and stored for 2.5 years inside a room ( ~22C) and covered with black pl […]
Show full quote

arncht wrote on 2022-07-17, 06:39:

badmojo wrote on 2020-08-01, 22:20:

I've given my retro plastics the 303 treatment but only started doing it about 6 months ago - impossible to know if it will have a positive effect but it can't hurt I don't think.

Any success? 😀 i think here would be more important to protect against the oxygen, the radiation (uv, heat) works just as a catalyst. The retrobright is beaching to release the oxygen, and they will reconnect after a while.

Retrobrighted plastic treated with 303 (several layers) and stored for 2.5 years inside a room ( ~22C) and covered with black plastic yellowed again. I am now doing another test with Renassaince Wax (https://en.m.wikipedia.org/wiki/Renaissance_Wax) which should be better at blocking oxygen.
There is a good explanation of the yellowing here: https://deskthority.net/viewtopic.php?p=228424#p228424 it seems that once the plastic is damaged by UV then the yellowing will continue even without exposure to UV.

There was already one attempt to test the wax by this guy: https://www.jackenhack.com/retr0bright-will-it-last/, unfortunately he didn’t finish it.

Yes, it will continue, until it gets oxigen. Maybe we should make a test with two pcs of abs, one should be stored in a vacuumed bag.

This wax sounds interesting… but the colorless, better quality shoe paste has very similar ingredients..

I started now a test where one part of retrobrighted plastic is covered with electrical tape - this will prevent oxygen access. And then I also applied Renaissance Wax to one strip, 303 to another and then I left one untreated and original condition. I will leave it near a window and hopefully I will report back the results in 1-2 years 😀.

Great test, thx.

Will the wax dry? Or how do you feel, if you touch it?

It dries quickly and then you can polish it, it's not visible at all and it's the most safe wax you can use. It has a very slight shine to it, but in case of plastic you can't tell the difference at all. It should be completely safe to almost any surface, that's why it is used to preserve even very old artefacts in museums. It creates a barrier on top of the surface to prevent further degradation from oxygen / moisture.