Some time ago, I received a 20-plus years old Apple Extended Keyboard (AEK). Meticulously, I stripped the keyboard to dust d own the PCB within, clean the two halves of the casing and the keyc aps. Despite getting a super-clean keyboard after all that hard work, I was unsatisfied with what laid before my eyes. What was wrong? Well , with the exception of the keys, the casing of the keyboard (along with the space bar) had yellowed considerably.
Now, this is nothing surprising; we all have plastics that had yellowed with age. Keyboards, mice, printers, gaming consoles - you name it. And no matter how you scrub it, you just can’t get back its original colour.
Determined to return my AEK to its former glory, I searched the Internet for a method to ‘de-yellow’ plastics. It turned out that there’s really a way to undo the damage. It’s called Retr0Bright. To shorten the chemistry lesson, essentially, the industrious folks behind the Retr0Bright project had discovered that it’s the bromine - often used as flame retardant in plastics that’s causing the yellowing. And the keys to reverse the process are hydrogen peroxide and ultraviolet (UV) light.
For those adventurous enough, the Retr0Bright wiki has recipes for making the RetroBright gel. Why gel? Because hydrogen peroxide isn’t exactly cheap. Also, making the Retr0Bright gel isn’t as easy as pie. If you’ve never heard of hydrogen peroxide, it’s unlikely that you’d know what is xanthan gum or glycerine, two other ingredients for making the gel. In addition, getting the mixture exactly right sounds difficult.
While looking for a ready-made peroxide gel, I chanced upon a post in the English Amiga Board, where a member recounted his success with an off-the-shelf cream peroxide product. Many others had also reported success, so I decided to give it a try. In short, yes, it really works.
And here’s how you can do it too:
01 GET THE JEROME RUSSELL BBLONDE CREAM PEROXIDE
The magic potion that you need is the Jerome Russell Bblonde cream peroxide (40 Vol 12%) that’s originally intended for bleaching hair. I reckon a lower strength (6% or 9%) will work just as well, except that it will take you a longer time. Also, it should technically work with similar cream or gel peroxide products, and there are plenty on Amazon. But this is what I used.
02 COAT YOUR YELLOWED PLASTIC GADGET AND WRAP IT
In a nutshell, all you need to do is to coat the plastic (cleaned and dried, of course) evenly with the cream peroxide. Avoid having the cream coming in contact with your skin or eyes, as it can cause burns. As such, I strongly recommend that you use gloves.
And while you’re at the handy man store, pick up a brush and some cling wrap too. The idea is to wrap the coated plastic parts, so that the cream peroxide doesn’t dry up too fast. I’ve more tips towards the end of this article.
03 SUN IT, OR SHINE IT WITH A UV LAMP
UV light plays an important role in the whitening process. So, don’t go and lock the treated parts in your cupboard. There’s no lack of UV light in sunny Singapore - all I did was to leave them on a table by the window. Alternatively, put the parts under a UV lamp. Remember to check the progress regularly.
This sunning process can take as short as a few hours to as long as a few days, depending on how severe the yellowing is. Once the plastic has regained the colour you wanted, wash the parts thoroughly, and ensure that no residual cream remain.
"Here’s what’s likely going to happen when you leave the coated plastic out under the hot sun for too long. There’s nothing you can do to undo this white ‘bloom’. Ouch!"
AND SOME TIPS
First and foremost, there’s no guarantee that this cream peroxide method will work on all yellowed plastics. So, think it through long and hard before attempting this on your vintage, only-one-left-in-the-world gadget.
If you do try it, remember to never let the cream peroxide dry up, especially under the hot sun. It will cause an ugly bleaching effect that unfortunately isn’t reversible (and I’ve learned this the hard way).
This is why I now leave the parts on a table beside the window. I would also check on them and turn them regularly, so that all the sides are exposed to the sunlight. Remember, what’s required is the UV light, and not the heat. If it’s impractical for you to keep checking on the progress, consider using a UV lamp.
Here’s a comparison of the difference before and after the cream peroxide treatment on the SNES.
I declare the Apple Extended Keyboard de-yellowing project a success.