Applied Retr0brite

This is a post I just made on the forums (old apple computers enthusiast forums) and it is in reference to a couple other decently long threads about making Retr0brite using drug store 3% hydrogen peroxide instead of “hair salon” concentrations

the advantage is I made nearly 10 gallons of the stuff for less than 7$, and since its mild its safer from mishaps splotches blooming and removing print

the disadvantage is its mild and takes longer

for those who dont know what Retr0brite is, its a simple mix to remove yellow / brown discolorations from old plastic

anyway, I know someone will be interested here :wink:

Since this weekend my was booked solid (graduation party, and mothers day stuff) I took Monday off, and WAS going to Retr0brite my apple //c, then looked at the weather and saw it was going to be “overcast and 40% chance of rain”

Great, so … since I was running around like a madman today anyway I went ahead and did it, if you look at the last picture in the post above I am still trying to discribe its yellow, … maybe mayonnaise mixed with plain yellow mustard?? Also I wanted to see how well the “drugstore” 3% mix would work on a machine so badly yellowed.

few weeks ago I hit up “dollar tree” (a store that every thing is only 1$, hit and miss goldmine) and got 6 1 litre bottles of 3% hydrogen peroxide and a half pound tub of “LA’s totally AWESOME Oxy booster”, I love that store

last night after my friends graduation dinner I soaked the case in warm water with regular dish soap, then scrubbed it with a nylon dish brush, that alone made the case nearly a shade lighter + it removes the question of “is that 25 year old coffee spit, or 25 year old flu snot?” from the keyboard

today I got up a little earlier and cleaned a couple clear plastic bins out, and made my mix which ended up being 3 bottles of3% hp, with 1, 4 gallon office waste can (clean) of water + 1 scoop of oxy per each bin, it took 2 of my bins to lay everything out

and the results! after 8 hours still a hint of yellow on the worst places, but dramatically better, and due to constant stiring, flipping and poking, everything is very even in between the different case pieces, the parts are uniform with no splotches etc and no damage to the print on the case

Over all I am very happy with the 3% mix, and while it did not get every single bit of yellow off of this really bad case the first time, it was well worth the little (but lets face it, hand scrubbing keys is tedious) effort, and the questions from my dad when I went to check my grill :slight_smile:

ps: yes all the keys match now, Ill post a assembled pic when its had a chance to fully dry out

Awesome! I have a printer (Tandy CGP-220 ink jet from the mid-1980s) that seriously needs this treatment (plus I need to figure out a way to reload the old ink cartridges, which might be an impossibility…

Can’t wait to see the final results!


the case is much whiter in person, Ill snap a pic in daylight once I can see how the small storms are going to blow over

I am happy with the results and probably will not do this case again soon as I have a couple mac’s to spiffy up and release

– fuzzy sorry



That’s insane. I will have to try it sometime. Is there any possibility of damaging what you are cleaning? Can it be too strong for the plastic?


yes it can, if you use the recommended mix it can splotch or bloom, if your using the gel mix it can dry out and do the same + you can burn through the print (so you have to keep a more watchful eye on things)

using 3% hydrogen peroxide its much safer, and seems to be more even IMO but it takes longer

Ok, thanks. I don’t actually have anything old that’s beige but if I get something I will know what to do :slight_smile:


Ok, thanks. I don’t actually have anything old that’s beige but if I get something I will know what to do

Most of the stuff affected by this issue is pre-1990-95ish plastics. It used to be thought that UV exposure (flourescent lighting, sunlight) caused it, and/or tobacco smoke; these both do cause yellowing, but from what I have read about the “history” of Retr0brite - the chemists and such who worked on it actually found that it was a bromine reaction or something with the oxygen in the air (coupled with UV and other things made it worse). This was as a result of a fireproofing of these plastics - old age chemical degradation.

Eventually, after using the Retr0brite solution (years), the plastic will yellow again; I have read that you can apply a UV-filtering clear coat over the top of the plastic to prevent this, if you wanted to.

Do some research on this; it is actually a fascinating story of a bunch of old computer geeks, some with chemical industry experience and such, wanting to preserve their old computers and restore them to “like new” condition; there are tons of old computers out there (many in museums) which have this condition that would look awesome if restored this way. They went on a quest, aided by the internet and a lot of worldwide experimentation - to come up with this solution. Surprisingly (IMHO) - it uses chemicals easily and cheaply found, so that any retro-hobbyist can do it.

As a retro-computing (and computing history) enthusiast, when I first heard about it, I was stunned; this was something that has plagued us for decades. I am glad there is a solution (figuratively and literally!) to the problem.


and it will work on any color plastic, not only beige, the “drugstore” mix I used would be perfect on any colored plastic (if its not painted of course), the strong stuff can cause blooming but again if your being watchful its easy to catch