Summer Computing – Retr0brite and Tandy WP-3

This will be a combination article about the Tandy WP3 and also about my experiences with Retr0brite. Given that this is the first dry day in the Lake District for about three weeks (so much for the Great British Summer!) it’s both an opportunity to process a couple more plastics using Retr0brite and also to enjoy the sun whilst retrocomputing with the Tandy.

Let’s first talk about Retr0brite. I call my own twist on Retr0brite the ‘Windermere Simplification’.

If you haven’t heard of Retr0brite it is a technique discovered by Amiga enthusiasts for reversing the yellowing of aged plastics. The yellowing is caused by a chemical reaction involving the bromide which is mixed during manufacture as a fire retardant. The quality of the plastic and the amount of bromide used, together with the length of exposure to the sun determine how yellowed the plastic becomes. Lighter plastics are affected more than darker plastics. The Retr0brite process involves bleaching the affected plastics with a mixture of hair bleach and a little oxy-action powder. This removes the yellowing and restores the plastics to their original colour. In an ironic twist the restoration of yellowed plastics requires the application of UV radiation (sunlight to you and me).

Rather sad looking VAXstation 4000/VLC before restoration

This yellowed DEC mouse is to also to get the treatment

What you need is:

12% Hydrogen Peroxide Creme (approx. 1/2 jam jar per application)
1/2 teaspoon of Oxy Action laundry stain remover
A jam jar to put it in
A paintbrush
Some yellowed plastics
A large clear plastic container
Pair of gloves
Eye protection
Some good old fashioned sunshine

My initial attempts followed the original recipe which uses straight Hydrogen Peroxide in liquid form, the complication with which is that you have to thicken the neat Hydrogen Peroxide with Xantham Gum and Glycerine. When I tried this I got a horrendous gloopy mess!

My method bypasses this step which saves a lot of hassle and potential mess. I got the creme from a hairdresser’s supplies warehouse – the creme is used to bleach hair. You may be able to obtain it on the internet, from a local chemist, or by asking in a hairdressing salon.

Equipment required

Always use protection!

Enough to do about four runs…

Before Retr0briting it is prudent to clean any plastics you are to process. This time round I’m processing the VAXstation 4000/VLC top case (as seen in my first 2012 summer challenge post) and a VSXXX-GA mouse. The case had sticker residue on it so I immersed it in a solution of washing detergent and hot water then scrubbed it with a Vileda plastic sponge before drying. This also removes any grease.

Use ordinary washing powder or liquid to clean plastics

Notice the sticker residue and the lighter patches underneath where the stickers had been – ideally this is the colour we want to get back to.

Leave to soak for half an hour

Retr0brite Recipe:

Put your gloves on first! It is prudent to wear some eye protection (don’t you look good in those Aviators!) but if you are a fashion victim and refuse to do so please consider it seriously at the stage where you mix the Oxy action in and also whenever using the paint brush. It’s not worth it!

Pour enough of the creme to fill about 1/2 a jam jar. This is enough to process 1/2 a computer case.

half a jam jar will do half a computer

The oxy action powder needs to be dissolved in water before it can be mixed with the Hydrogen Peroxide creme. Put 1/2 a teaspoon of the powder into a pot/cup/ramekin and mix with a little hot water. Leave this to stand for 5 minutes and then stir until most of the crystals have dissolved (I say ‘most’ here because I’ve not yet got it to all dissolve!)

Half a teaspoon of oxy-action

Use an old ramekin or cup for mixing

Add a little water

Leave for five minutes then stir until most crystals are dissolved

Ready to add to the hydrogen peroxide

Add the oxy action mix to the Hydrogen Peroxide creme. I would recommend wearing something old at this point and putting your eye protection on. Tilt the jar away from you and stir gently at first until the two liquids have mixed. That way if any comes plopping out (not uncommon) it won’t go down your nice posh shirt (can you tell I’ve done that?)

Pour the oxy-action into the hydrogen peroxide

Stir the oxy-action in slowly but thoroughly – point the jar away from you!

You’re good to go! Keep the mixture inside when not in use as the sun activates it. You’ll find it is fairly runny at first but develops into more of a foam as time goes on.

Completed mixture, ready to go!

Take everything outside and place the plastics to be processed in the large plastic container (I use a storage container).

Using the paintbrush apply the mixture. The most important thing here is coverage rather than neatness. When you have covered the plastics in the mixture place the box in the sun preferably with a lid on.

Having the lid on doesn’t appear to affect the time it takes appreciably and keeps the mixture from drying out which can cause streaks.

Reapply at least once every hour and a half. I do this throughout the day – you can see the process working from about the third application and it appears to take about five hours or so in reasonable sunshine to complete.

Try and point the worse affected plastics towards the sun light and move the box as the day goes on to continue to catch the sun. Don’t worry if clouds get in the way – there is still UV acting on the mixture and the process will continue to work.

Note that as time goes on the mixture will become more of a foam which solidifies after exposure – it is important to add new mixture to the plastics to ensure that the foam stays moist to prevent streaking.

Expect the process from start to finish to take around five to seven hours. If you find the plastics are still yellowed after processing you can start again for a repeat and get an improvement.

Try and keep everything inside the plastic box…

Coverage is the most important aspect. Notice how here the mixture hasn’t foamed up yet

First coat of the front – notice the colour of the plastics here

Applying to the top of the case

Mouse plastics have their first coat

First coat of everything completed

Put the lid on to stop the mixture drying out

This is after a couple of coats, applied every hour or so. Notice the plastics are significantly lighter already…

You can see here the mixture foaming as it reacts. This makes it easier to apply. The contents of the jam jar will also start to foam.

Towards the end it is clear the process is working nicely. Note that the VAXstation label here is totally plastic so OK to apply the mixture to.

The mouse plastics just before rinsing and drying

Once finished carefully (put those shades and gloves on!) wash off the mixture and dispose of responsibly. Simples!

The results!

On the VAXstation plastics note how the colour is now even across the front (original photo first):

The discoloured plastics of the VAXstation 4000/VLC front panel

Note how the front panel colour is now even all the way across (with no yellowing!)

And a comparison of the mouse plastics, before and after against a brand new mouse shows that the colour is almost fully restored to the original:

Mouse on the left is the before application of Retr0brite, mouse on the right is a nearly-new control

Notice how the mouse on the left actually looks better that the mouse on the right – slightly less yellow, back to the original grey!

Now some do’s and don’ts that I’ve learnt the hard way:

1. Do wear eye protection. If you get hydrogen peroxide on your skin wash off immediately.
2. Do remove any darker plastics and put to one side. It’s tempting to do everything at once but darker plastics tend to have a more variable response including inconsistent effects which results in a blotchy appearance. Rule of thumb: if it doesn’t look yellowed don’t retr0brite it. The benefits will be minimal but you could alternatively make it look worse than it already is. THIS IS NOT THE IDEA!
3. If possible remove all labels or name tags. If this isn’t possible be careful what you use to cover them up. I used electrical tape which was a bad idea – even though the nameplate was metal the painted decal lifted when I peeled off the tape.
4. Cheaper plastics typically have more inconsistent results. For example the plastic bezel of a floppy drive is likely to be lower quality plastic than the plastic used to make a computer case.
5. If you run out of mixture make some more up rather than trying to stretch what you have. For the extra cost it’s a no brainer.

Talking of cost, the 1 litre bottles of Hydrogen Peroxide cost me around £5 – clearly at 1/2 teaspoon a go the oxy action cost is negligible. So I guess on average if you were to take two sessions to do a complete computer you’re talking around £3 all in. Not bad eh!

Here are some before and after shots. My first attempt was on a Brother HR-10 daisywheel printer which was badly yellowed but looked good as new (a very white shade of cream) after processing.


Brother printer as I received it

With only the top half done – notice the contrast in colours!

Completed retr0brite and re-assembled printer. Nice!

Lovely creamy plastics!

My second attempt was the front plastics of an AlphaServer 300. This was where I made the mistake of using electrical tape to mask the nameplate and also processing the darker plastics. The plastic which contained the name plate didn’t look any better afterwards, the plastic floppy drive bezel is now patchy.

The AlphaServer plastics before processing. Afterwards they matched the non-faded powder-coated metal chassis perfectly

My third attempt is the VAXstation 4000/VLC which was quite yellowed. Interestingly it had some sticker marks where the yellowing hadn’t taken place and as you can see from the previous results the colour is now consistent.

Good luck!

Some notes on the Tandy WP-3

I’ve used the Tandy WP-3 to write these notes. One thing that I instantly noticed is that it is quite difficult to write on when holding it on your knees – the fold out feet are no help (this is one area where the Z88 had clearly been thought out better as the fold out ‘feet’ are in fact a long bar which would rest on your legs.

As the screen is the same angle as the keyboard you really need to be sat with it on a table and be at a comfortable height – if you are sat too low the screen is hard to read.

Hammering away on the WP-3!

Apart from that no worries! It’s not the best keyboard I’ve used but equally it’s far from the worst and actually although the feel is a little dead at the bottom of the keystroke it compares well with any modern keyboard and certainly beats trying to use the iPad 3’s glass keyboard!

I’ve had a play with some of the retro-offerings in the daylight readable screen department for retrocomputing devices and this screen is very good in direct sunlight or indeed a cloudy day (can you tell the weather here is on the turn!) For £6 which is what this cost me I really can’t complain! Mine was a little bashed up when I got it which is fine – one less thing to worry about. When editing text if you are inserting or deleting in the middle of a line the display update gets sluggish as the processor struggles to re-format the line after each keystroke, but when typing afresh or adding to the end of a paragraph it happily keeps up with my reasonable typing speed (note again that the Z88 is better thought out in this scenario – it delays updates to the screen so that the text modifications are captured correctly. Only when you stop typing is the text then updated on the screen).

The editing key combinations take a little getting used to (F1-9 for SELECT for example, F1-0 for COPY) but on the whole it is easier to get along with than the Z88 which was a lot stranger (which obviously makes it a little more ‘exotic’ at the same time).

I’ve written a separate blog post about expanding the internal memory from 32K to 132K.


  1. Most excellent work sir! You can get the Hydrogen Peroxide Creme on Amazon, mine’s on the way. I’m hoping we’ve got some Oxi in the cupboard. Really looking forward to trying this, I didn’t realise you had to leave it in the sun, seems kinda counter-intuitive given it’s the UV rays that caused the problem in the first place! You’d definitely get you pencil sharpened for this one.

    • You gotta love it! Good to know amazon do it, makes it much more accessible to us geeks – talk to a hairdresser, are you mad?
      For some reason the plastics on the later VAXstations don’t suffer at all from yellowing (I’m thinking of the 4000 series). I just put the processed VLC cover back on and it looks great sat on top of the 4000s, exactly the same colour!

  2. Hi Urbancamo.

    Thanks for posting this great guide on how to use retrobright! I was wondering how to apply the solution and your photos are a great help.

    It must have taken extra effort to continuously switch between using your gloved hands to coat the enclosures with the caustic retrobright solution, then switching to a bare hand to take photos of the process, then going back to gloves to reposition the plastic enclosures.

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