How Retr0brite was developed

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Retr0brite Project
Retr0brite Project


The “Retr0brite” Project

How to deal with the “not-so-mellow yellow” of old computers and consoles Anyone who has dug their old computer or console out of the cupboard or loft for some retro gaming will probably have noticed that it maybe hasn’t worn to well with the test of time. The plastics these machines were made of is called ABS and to make it flame retardant (just in case it catches fire after a marathon session) the plastics manufacturers added chemicals which made the plastic turn yellow or, even worse, brown. It was originally thought that the yellowing was permanent and that only solution to this was to paint the plastic in its original colour and cover the problem up. However, a chance discovery was made in March 2008, by the CBM Museum at Wuppertal in Germany, that immersing parts in a solution of hydrogen peroxide could partially reverse the process. This was initially taken up by the Amiga community in Germany ( and the idea eventually found its way to the English Amiga Board (, where a madcap collection of chemists, plastics engineers and retro hackers managed to perfect this concept with help from other forums and put it on steroids.

Dave, aka Merlin, the chemist behind the project, explains. “I came across the use of peroxide in July 2008 when Kristian95 told us about what they were doing with it over at I was intrigued by this, as I am a former industrial chemist. I am also a plant safety manager by trade and, purely by coincidence, around that time I read about a dust explosion that had occurred with a chemical called TAED, which is the booster in the ‘active oxygen’ laundry products.”

“This got me thinking, and after some really full-on serious chemistry discussions with other EAB members, like rkauer in Brazil, who is a plastics Engineer and my good friend Zetr0, who endured endless phone calls from me and some epic threads on EAB about the possible causes of the yellowing, we had arrived at the theory that it was the bromine in the flame retardant that was the cause. We also knew that Ultra Violet light was another factor. Having identified the culprit, the next stage was to try to develop and perfect a means of treating the plastic and reversing the yellowing without damaging the plastic. Being a former industrial chemist helped me tremendously, in understanding what was going on at molecular level and develop a treatment process to reverse the effect.”

Proof of concept

“The problem was finally cracked in late July 2008 with a mixture of hydrogen peroxide, a small amount of an “Oxy” laundry booster as a catalyst and a UV lamp. Proof of this concept was demonstrated on EAB by Tonyyeb, Chiark and myself.

Spreading the idea

Then we took the idea to other forums, where the idea received a sceptical response at first. Lorne from Arizona and Tezza from New Zealand from the Vintage Computer Forums ( really took on the idea and helped us perfect the process between VCF and EAB. We have now proved that plastics yellowing can be completely reversed in hours using our mixture.”

Developing a Gel version

“All of the initial tests were done with a liquid and we realised that for large parts this was getting expensive, so the next stage was to make a paintable “gel” that could be brushed onto larger surfaces. This was tried in Ariziona in the sun and the UK under a UV lamp and was found to be just as effective as the liquid. We have now released this to the public domain for anyone to use as we can’t patent it and we coined the nickname “Retr0brite” for it, as it summed up what we were actually doing with it.”

“The most extreme test we have done to date was a Commodore 64, which was treated in several stages by myself over an eight-hour period, to show what could be achieved; this was a particularly impressive result”.

Figure 5. The Commodore 64 experiment (treated side is on the left!)
Figure 5. The Commodore 64 experiment (treated side is on the left!)

Spreading the Word

“We now have active threads about this at several forums across the World and we have now set up a Retr0brite support thread for those who are interested at our retro computer trading site, AmiBay ([”

Merlin sums things up

“There were an incredible number of people at first that said this was impossible – that was until they saw the pictures, then tried it and proved it for themselves. The usual reaction was ‘No way!’ then ‘WOW!!’.

This has been a truly global effort by retro enthusiasts and has proved to work on Commodore, Atari, Osborne, Apple and other machines and the work still continues on various forums worldwide. As long as you protect yourself against the hydrogen peroxide, this is pretty goof proof and I hope that others get to see the amazing effect we spent so much time working to achieve.”

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