Retr0brighting Guide

What is Retr0brighting?

Many old computers contained flame retardant chemicals mixed in with the ABS plastic known as bromine. Over time, with exposure to UV light and heat, the plastics start to yellow. Some systems show this issue more than others and can really spoil the look of these beautiful machines.

Can the yellowing be reversed?

There is something we can do to bring them back to their original colours. But you need to realise this is not a permanent fix and the yellowing will eventually return. For this reason, I purchased all the things I needed to easily carry out this procedure, so any systems that start to discolour again can be easily topped up.

The different methods

There are a few different methods that can be used for this process. the first involves simply placing the plastics out in the sun. If your case is not very yellowed then this may be enough to fix it. However, in the UK we tend not to get much sun so I have never tried this method myself. You also need to be careful that if the sun gets too hot, plastics can melt or warp. Personally, I wouldn’t recommend this method.

The next method is covering the case in a 40 vol hydrogen peroxide cream which is used for bleaching hair. Once the case is evenly covered, wrap it in cling film to help prevent the cream from drying out too fast. Then place the case either in the sun or under a UV lamp.

I have used this method a few times and it does work. My preference is to use a UV lamp rather than the sun as it feels like a much more easily controlled procedure. It does take longer using a UV light but this makes it less likely that the cream will dry out which can then cause streaking or a marble effect on the case. Because of the slight risk of this happening, I no longer use this method and instead use the method that follows.

My preferred method

So this is the method I now use with all of my computers/consoles. I find using this method I get consistently perfect results, I don’t need to rely on good weather, and there is no risk of the case melting or warping.

You will need the following materials:

  • A clear plastic container with a clear lid that is big enough to hold your case.
  • Hydrogen Peroxide 6% (Enough to submerge your case within the container, mine takes between 15-20 litres)
  • A high power UV Light source (I use a 50w UV Flood Light from Amazon)
  • Tin foil to reflect the UV light around the container
  • Rubber gloves for handling the hydrogen peroxide
  • A funnel for getting the hydrogen peroxide back into it’s original container so it can be re-used at a later date.

The first step is to strip down the computer/console we want to retr0bight. For this guide, I’m going to be doing a recently acquired Acorn Electron. The keys on this computer are fairly yellowed and it also has some yellowing on the top of the case.

Now get some of the tin foil and lay it on a flat surface, this needs to be big enough to cover the bottom surface of the box. This then acts as a reflector and helps provide a uniform UV light source. Once done, place the box on top of the tin foil.

We can now fill the box with some hydrogen peroxide and also wrap the outside of the box with some more tinfoil. We are going to start by doing the keys, so we will place the keys in the peroxide and give them a mix around to get rid of any air bubbles.

The next step is to replace the lid and turn on the UV Lamp. I normally leave the items overnight to make sure they are fully brightened, but the actual time will depend on how yellow the plastics are.

Once their UV bath has been completed we can take the keys out, rinse them under clean water, dry them off and view our results.

After this, we simply repeat the process with the shell of the computer. You may want to use something to weigh the case down a bit if you find it floats above the surface level.

The Result

Here we have the re-assembled unit, before and after. I think you’ll agree it looks much nicer back in its original colours. (Click the thumbnails to see the full size images)