exxos's Atari, Amiga & retro forum

THE RETROBRIGHT EXPERIENCE.
This is not "The definitive guide of the retrobright"; it is only my personal experience with this procedure and I detail the tests, the errors and the correct ones. I am not responsible for the result obtained by other people.
The materials needed for this retrobright are:
- Gloves (the hydrogen peroxide cream burns the skin).
- Hydrogen peroxide cream at 40 volumes (12%). A small bottle of 75 ml costs about 0´5 €. Two bottles are required for a computer and separate keyboard.
- A roll of transparent film (used to wrap food).
- Sunlight.
- An Atari computer with unwanted yellow or brown color (or a MegaFile device).
- Patience.
Experience:
- Disassemble the computer (and its separate keyboard, if you have one) and clean the plastics with soap and water. Use a brush for the grids. Rinse with water and dry it with a rag.
- Protect the Atari label with adhesive tape.
- Pour some cream into a bowl and use a clean brush to apply it on the casing. Apply the cream evenly throughout the surface.
- Cover the casing with the transparent film, avoiding too many wrinkles and air bubbles. Another person can help you with this operation.
- Place the casing in a very sunny place, for two or three hours approximately (depending on the country and season).
The best sunlight is in the morning or in the afternoon, but the time interval from 2:00 p.m. to 4:00 p.m. is not convenient because the process is done too quickly and uncontrollably; resulting spots or "vascularization". I suppose that this aspect is due to the high temperature that in Andalusia (Spain) adds to the enormous illumination in those hours of summer, producing an accelerated chemical reaction and a premature drying that obtains an irregular color and even white patches. The hours can be complete in other countries or in other seasons.
- Every half hour verifies that there is the necessary humidity that provides the melted cream. If dry areas are located: do not put more cream on top; you must remove the film, clean the casing with a dry cloth, re-spread the cream and cover it with new film. The important thing is that there is always with humidity, because the dry cream produces stains of different shades of gray or even white.
- After two or three hours, remove the film and wash the casing with soap and water.
The result has been disastrous !!
Do not worry, it is very difficult to get a perfect result in the first session; tomorrow repeats the whole process.
The second time you will see a more pleasant result. If is necessary: Repeat a third time the next day.
Observations:
- During the process, the optimum conditions occur while the cream is slowly in effervescence, taking care that it does not dry.
- A keyboard without disassembly should not be exposed to the sun for more than 15 minutes, always with the capacitors and chips covered with a rag. Higher exposures can damage the electronic components, for the temperature and the chemical reaction that is occurring.
Happy retrobright and may the TOS be with you.

Fantastic

Did you have any problems with evenly coating or "blooming"?

Take a image again in 6 months time as well. Most say the discoloration comes back after a while.

I used the same method on my Amiga 1200, with very good results. Since it was winter when I did this, I used a slightly different setup using a box layed out with tinfoil and a very strong UV source (Osram Vitalux 300W) above it. Since heat seems to have an accelerating effect, this took significant longer. Can't remember exactly, but I think around 24h. But the result was nice and even.

Some experiences I can add:

• If possible, lift up the keycaps and treat them seperately, the printings weren't harmed in any way
• I had good success with cleaning the case parts in the dishwasher. I even put the keycaps in the basket which could be closed in my case. You can use a net instead of course.
• I put the keycaps in a small plastic bag, put the cream in and "massaged" it in. Works great
• If exposed to UV light, the yellowing (or greening in some cases) will return. Keeping it under a dust cover helps preventing that.
• And DEFINATELY wear gloves, eye protection and an apron. The hydrogen peroxide cream burns your skin, leaves white spots, ruins clothes and may damage your eyesight permanently, so be careful! I really can't understand that people actually put that stuff in their hair...

exxos wrote: ↑Sun Sep 03, 2017 1:32 pm Take a image again in 6 months time as well. Most say the discoloration comes back after a while.

On the Amiga case, it did not return that much, the treatment was 1.5 years ago. But as said, when not in use it is kept under a dust cover and the room is facing to the north, so not that much UV anyways.

I've had all sorts of problems, it's not easy to get a good result.
Wrinkles in the film and air bubbles cause uneven discoloration and the dry areas cause white spots. High temperatures accelerate the process and make it difficult. Excessive solar radiation also "burns" the color of plastic.
I have needed three sessions to get an acceptable result.
I do not know when the discoloration will return, but the Mega ST was looking lousy and had to be corrected. Maybe it will not return to the color before the retrobright, it will always be better.
I take the risk because I was determined to use paint if it was not solved with the retrobright.

Someone has used colorless lacquer or varnish to protect the plastic from reaction with ultraviolet light.

Sounds like the problems I had.

I tried liquid peroxide last year. I tried a mouse in a small bath of it, left it in direct sunlight, it did go a little lighter, but not much.. I will try and find the images tomorrow. It did not seem like leaving for longer did anything. But some people said leaving it for a week even out of sun light still works.. So I may try again.

Personally I originally tried the recipe from the Retr0brite page (http://www.retr0bright.com/) a couple of years ago. Since then, the hydrogen peroxide creams seem to have come to the fore with more consistent results.

The main problem I had was getting a consistent mix, since you're actually making a gel which contains hydrogen peroxide, which you activate when needed with the 'Oxy' cleaning agent.

Despite using a blender, and following the instructions to the letter, the mix was inconsistent and lumpy, plus super sticky. I tried it on an Apple keyboard and mouse, and it was ok, but not quite as good as I'd hoped.

I then tried an ST case, and ended up with bits that worked, bits that didn't, and some bits that had blooming (You can just about see this on the 3rd ST back). I haven't tried since, but I have a number of ST cases that really could do with 'the treatment'.
I will get some 40 vol creme and try again I think, as I have a number of STs, plus some Apples and a SNES, that deserve to go back to their best.

Interestingly, my A1200 has not browned, yet another recipe no doubt.