Retr0bright Support Thread

Ok that's not a control at all but a comparison aid for when I take a photo. I dont have spare iic's.

if UV light on its own reverses the yellowing caused by UV light, will it go white on their own again? please expand that as i've not heard of that effect thus far.

Also you say the ozone would be gone, do you mean a reaction has occurred and its no longer ozone, or leaked away?

thx!

Hello Ian,

Yes, the reaction happens from only the sun itself- it has a bleaching effect. This is partly why people used to hang their clothes outdoors (other than the drying effect). It takes several bright days to happen, but you can just put the whole computer and keyboard outside, which is nice (no disassembly).

Here is one experiment here (in German).
https://www.forum64.de/index.php?thread/23585-versuche-zum-thema-gilb-bleichen-und-sonnenlicht-uv/

And another thread about the effect and other's experiments.
https://www.forum64.de/index.php?thread/82879-bleichen-nur-durch-die-sonne/

-Pete
 
hi pete

I wasnt expecting that!

Thank you for the links to the threads. is the [current] consensus then, heat (perhaps from sunlight)/ IR whatever) makes the treated plastics go browner, sunlight appears to have a bleaching effect, not making it even browner?
 
hi pete

I wasnt expecting that!

Thank you for the links to the threads. is the [current] consensus then, heat (perhaps from sunlight)/ IR whatever) makes the treated plastics go browner, sunlight appears to have a bleaching effect, not making it even browner?

Yes, it is strange. I don't think anyone fully understands why it happens exactly, which may mean several factors can cause it. But yes the sun by itself seems to return it to the original color, slowly.

The fact that it browns unevenly is the odd part. I'm not sure anyone knows exactly how something has sat for years in storage or use. Sometimes I see a machine that is half brown on one side and have to wonder how it was stored to cause that. Obviously you can see where a monitor or tape has covered something, but is it because it is starved of UV or oxygen or Flourescent lighting? That experiment would take years...
 
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Ok that's not a control at all but a comparison aid for when I take a photo. I dont have spare iic's.

if UV light on its own reverses the yellowing caused by UV light, will it go white on their own again? please expand that as i've not heard of that effect thus far.

Also you say the ozone would be gone, do you mean a reaction has occurred and its no longer ozone, or leaked away?

thx!

Hello Ian,

Yes, the reaction happens from only the sun itself- it has a bleaching effect. This is partly why people used to hang their clothes outdoors (other than the drying effect). It takes several bright days to happen, but you can just put the whole computer and keyboard outside, which is nice (no disassembly).

Here is one experiment here (in German).
https://www.forum64.de/index.php?thread/23585-versuche-zum-thema-gilb-bleichen-und-sonnenlicht-uv/

And another thread about the effect and other's experiments.
https://www.forum64.de/index.php?thread/82879-bleichen-nur-durch-die-sonne/

-Pete

It works but you dont get any benefit if it doesnt "see" the sun.. so you have to position it carefully for even effect and it wont clean, say, the sides of the case very well. Ozone gets everywhere
 
hmm

well, we seem to have run out of sun in the UK, so 2 days in the garden, not much effect. well, the apple looks a bit lighter.. but not dramatically so. yet.

Then I found a rip in the vacuum bag.

so, I got some more, this time sucked all the air out of the bag before starting, attached the ozone generator and now have 2 blown up bags of ozone, one with a C64 in and one with the apple 2.

its forecast to stop raining ! for a few days, i;'ll get them back out and rotated twice a day to see what happens.

Ozone is unstable.. will the ozone decay away and make this 2 day effort, pointless, if I dont empty the bags and start fresh every few hours??

any chemists to reinforce if this is, altogether, a realistic idea or not?
 
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bearing in mind the 'other threads' say it may take some time, and then any effect may be more visible some time after treatment.

I've left an apple iic, a c64c outside in uk clouds/sun for about 4 days and believe i can see significant improvement. I have now added a bbc b. The bbc already had just the top lid retrobrighted with bblonde, the bottom was original yellowed, significantly more yellow. 1 day in an ozone bag in sun, got pretty hot in there, seems to be very near match now

pics seem more yellow than I'm seeing taken under electrical light 8pm.
IMG_0928.jpg
apple ii c, the pics dont quite show the change. Its...8 out of 10 white. definite improvement.

c64, not a massive improvement, the slowest effect... this one will get more days in the sun.

ive been vacuum emptying the bags and filling up with ozone every other day or so.

I'm done now, will report back in a few weeks if anything has changed. any plastic / chemists about to comment please????????

apple 2c after 3 days, rotating. a slight improvement.
IMG_0890 (1).jpg


after 5 or 6 days total. It seems more even, a shade lighter.
IMG_0926.jpg
c64 needs.. well the case is better, keys grotty still. taking ages
IMG_0891.jpg
 
There is a video on youtube that shows it can be done with no sunlight whatsoever (If you are feeling brave!).
 
I searched retrobrite no sunlight and found a few. wowsa! err.. not for me :) Ive got too lazy.

btw! summers over by the look of it. I will look over the c64 in a week or two. I'm a bit disappointed in my photo's as the computers now all look less yellow in real life. but photo's are all i have to prove so.... I'll take some more in a few weeks.

ta:)
 
I've done some keys without sunlight or peroxide The results are stunning so far. I'll be posting in due course once I perfect it a bit.
 
I have 1 litre of hydrogen peroxide at 30%, should it be diluted before use on my Amiga plastics. I was considering to add 1 litre of warm water to it in a plastic container to use as a bath for the parts.
 
I have 1 litre of hydrogen peroxide at 30%, should it be diluted before use on my Amiga plastics. I was considering to add 1 litre of warm water to it in a plastic container to use as a bath for the parts.
30% solution should be handled with extreme care. Handle it like you would concentrated acid. A drop in the eye could make you blind on it and mixed with the wrong items it could react explosively. And I don't see why you would use warm water - cold water is safer to handle and will not make much of a difference in the effect.
I would dilute it below 5% - I have used 3% solution with good results. It will be slower but it seems to provide a cleaner result with a smaller risk of getting blotches. If you are not in a hurry it will get there eventually and you don't need to watch over it every minute to catch it before it goes too far.
 
Yes, I'll have safety glasses, full face visor and gloves etc. I use to use it with HCl for etching PCBs. I wanted 12% for this but the chemist had only 30% or 3%. I'll most likely mix it down to about 10% if its just as effective. It's the first time I use it for this application and don't want to damage the plastics if its too concentrated.
Does the Oxy addition make much difference? I was going to put the parts submerged in a container rather than make a paste and paint it on.
 
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I have good results just using oxy additives with luke warm water to treat keycaps for example. No need for hydrogenperoxide, or sunlight for that matter. Usually I soak it 2-12 hours depending on the condition. Peroxide might also work fine on its own but it is a lot more expensive. :)
 
Has anybody successfully restored yellowed spiral cords from keyboards ? Some cautious experiments with the gel did not do any effect.
Therefor and for cleaning convenience I generally put any old cords into a glass of luke warm water with 4 denture cleaning tablets.
I use those with a Oxi effect for smokers. The electrical connections ar kept out of the solution by clothespins.
 
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