MAKE | Un-Yellow Old Plastics

Have you noticed how old plastics yellow in the sun? Well, now there is an easy way to restore the original color!

Retr0brite is an easy-to-make open-sourced gel that un-yellows the flame retardants found in ABS plastic. It started as a chance discovery that hydrogen peroxide partially helped banish the yellow… but then it was refined in to an easier-to-use and more powerful version by a variety of retro computer enthusiasts, chemists, and engineers.

The recipe is a simple mix of hydrogen peroxide and oxi laundry booster, plus something to gel it so that it can stay attached to the plastic while it works. The actual bleaching process uses UV light (either a special light, or just leave it in sunlight) to activate the reaction, causing hydrogen to bond with bromine free radicals & undo the damage.

The Science behind this.
Gallery of more examples.
(there seems to be some confusion on the spelling – it’s also known as Retr0bright)

[via waxy]

10 Responses to Un-Yellow Old Plastics – Retr0brite!

Jack of Most Trades. on March 3rd, 2009 at 7:26 am said:

I thought it was cigarette smoke that turned the plastic brown. About the time I quit smoking, I started getting keyboards, etc. in black plastic.

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bekathwia on March 3rd, 2009 at 9:37 am said:

Wow, cool! My old knitting machine has this problem. I think it was partially beige to begin with, but it’s definitely yellowed (it’s from the 80s). Thanks for this!

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Bob Sinclair on March 3rd, 2009 at 10:42 am said:

I’ve thrown out working retro computers because they turned as yellow as a lemon. No amount of scrubbing with soap would undo this.

If I had known this method, these machines would now be restored to their former glory!

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Sal on March 3rd, 2009 at 11:13 am said:

By Gel, do you mean literally a gel, or do you mean just a container to mix it in?

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saint_al on March 3rd, 2009 at 11:52 am said:

Commodore restoration! I bow.

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Tim on March 4th, 2009 at 7:49 am said:

This is relevant to my interests.

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John Maushammer on March 4th, 2009 at 10:02 am said:

@Sal – literal gel. Check out the recipe page, where they use either Xanthan Gum+Glycerine, or Arrow Root. They also think corn starch, guar gum or even wallpaper paste may work, but those are just ideas to try. The original formula didn’t use a gel, and, as a result, required much more h2o2 to submerge the part to be restored.

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Ligia on March 5th, 2009 at 12:15 pm said:

This strikes me as the touch of brilliant madness, it calls for profound respect and at the same time commands the sheer mistery of taking these old computers and videogames ot of the placid flux of time, their quiet aging, to yank them right into the present, looking as befuddled as real time travellers would be, condemned to an era they do not belong to. Brilliant! Best of the year so far!

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malarkki on March 7th, 2009 at 12:00 pm said:

My vintage Super Nintendo can sure use this. Part of the box used, i guess, the un-antiflammable plastic. As such, some of the box is the original grey and other parts the ugly yellow.

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Kris on February 2nd, 2013 at 11:55 am said:

What about painted plastic (like the Commodore 64 logo strip at the top)? Does this fade the paint (since the hydrogen peroxide is essentially a bleach)? And if so, is there any other way to un-yellow plastic without stripping/bleaching the paint?

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