PLASTIC RESTORATION

Please note, that any advice taken on these pages is done at your own risk. 

Remember - always test on a part that is not on show!

Plastic Restoration

This page is built up of other peoples experience when restoring old plastic telephones.  As it says above, it's all done at your risk, so always test on a piece that does not show.

Click here for Bakelite telephones

300 Type ivory telephones
The cover of the Ivory cased 300 type is generally made of Urea Formaldehyde.  These can go a sort of mottled yellow-orange patina, there will probably also be small stress cracks filled with dirt and the surface is rather matt (un-glossy).

It is thought that soaking in hydrogen peroxide (sold for cleaning false teeth and babies' feeding dishes) makes the dirt in the cracks disappear.

If the blemishes don't go to deep you can get a fair result using car body rubbing compound and a lot of elbow grease (try Halfords Rubbing Compound - Cat code: 421107).

Paste Polishing No. 5 (Baykobrite) is good for cleaning up the cases and getting a shine back, followed by brisk buffing up with a soft cloth.  This product can be purchased, in small quantities under the name Baykobrite, from The Radiophile, Larkhill, Newport Road, Woodseaves, Stafford, ST20 0NP. (Telephone 01785 284 696)

Coarser than Paste Polishing is T-Cut (Halfords or any car shop).  T-Cut can leave scratch marks if your not careful and it is best to not shake the tin too much and just use the liquid (instead of shaking the tin to form the paste).

If you intend to use a buffing wheel then the advice is to be go for a abrasive that is not too coarse. Jewelers rouge or blue seem to fit the bill, as they're both buffing compounds rather than cutting compounds and won't (shouldn't!) do too much damage.  Wikipedia suggests "blue with a string mop" for use with plastics: http://en.wikipedia.org/wiki/Polishing_(metalworking) which sounds about right.

BUT - be careful not to over do the buffing.  If you do you end up exposing the fibre reinforcements which at best will give a mottled look you can't get rid of or at worst, expose something nasty (sometimes they used wood fibre, sometimes they used asbestos...)

700 Type plastic cased telephones
Cleaning
To generally clean a case use luke warm water with a little washing machine liquid.  Do NOT leave the plastic submerged for any length of time as the colour may well change.  Wash with clean water and dry well afterwards.

To remove any glue or stickers use White Spirit and for pen marks use Methylated Spirit.

For the final finishing it is actually better to use plastic polish and the best is made by Greygate.  They also sell a special cloth of the correct �hardness� for applying the polish.  If you use a duster or an old T-shirt, you are wasting your time, as a hard (and flexible) cloth is required.  This cloth lasts a lifetime and can be washed in soapy water after polishing.

Follow this link for the special cloth - http://www.greygate.com/product/application-cloth/

and

Follow this link for the Polish - http://www.greygate.com/product/plastic-polish/

Discolouration
Discolouration is a major issue with modern plastics, caused by the Bromine-based fire retardant which is added to the plastic.  There is no real definitive answer as yet, except to keep the items away from direct sunlight.  The RetroBright process is used by some collectors and this involves Hydrogen Peroxide and Ultraviolet light.  It is generally used to remove 'yellowing' from Acrylonitrile Butadiene Styrene (ABS) plastics.  GPO telephone cases, made of ABS, are marked with the number 17 inside the case.

There are no guarantees with these processes so any feedback would be appreciated.

There are some additional precautions you should be aware of when learning how RetroBrite works:-

• It is at your risk as the process is not 100% and no clearly defined process has been found as yet.
• RetroBrighting will most probably destroy any rubbers, PVC materials, or organic materials such as leather or cloth.
• Ensure a constant source of UV as shadows may cause patches to appear.
• The process is not permanent and will need to be repeated every few years.
• Please beware as it is possible that the process makes the plastic more brittle with every application.
• Wear gloves and cover up open containers.
• Use clear containers.

RetroBright 1  - At your own risk.
The process works by submerging the item to be RetroBrighted into a container of Hydrogen Peroxide (3%) mixed with water and leaving it under a UV light (or the sun if bright) until the plastic turns back to its original colour.  The item needs to be cleaned of dirt and grease, because if if any is left on the items blotches may appear.  Ensure that the item to be cleaned is completely covered by the solution and agitate the solution, by shaking the container, every so often.  Cover the container but make sure it is ventilated.

RetroBright 2 - At your own risk.
This is a vapour method was tried by guy called Simon Lock on computer casings.

This method requires placing a small amount of specialized food grade volatile liquid hydrogen peroxide (12%) into a sealed container (must be air tight) with the plastic piece that you want to treat.  Placing the container in direct sunlight will help expedite the chemical reaction to de-yellow the plastic.  This process can also be done indoors with the container next to a window getting indirect sunlight.

Some of the pros of using this method is that it requires much less hydrogen peroxide liquid since you are not required to completely submerge the plastic piece you want to treat.  Additionally, it produces a very even and constant result!

Others who have tested this method with coloured shells have found the results to be very good as well.  Traditional methods of RetroBrite sometime can bleach the pigments in coloured shells producing undesirable results.

RetroBright 3  - At your own risk.
Not quite RetroBright but was tried by a telephone collector to restore colour to telephone 706/746 cases.  A transparent storage box filled with lukewarm water and a scoop of �Oxy Action Vanish� added.  The box is then stood outside in the sunlight (UV) for the afternoon.  It seemed to work better on some cases than others.

RetroBright 4  - At your own risk.
Some people have been experimenting with an alternative process which isn't UV dependent.  Probably good for small items.  A chemical mix (Peroxide + Vanish) but applied as a cream to the item, which is then put in a zip lock bag and immersed in a temperature controlled water bath.

The water baths are called "Sous Vide" heaters, which are designed for cooking.

This process is fairly new so check out on Google.

RetroBright 5  - At your own risk.
Another collector tried numerous experiments.  The most successful was using Sainsbury's Oxy Bleach, but another chap used the Vanish version and the results were similar.  The solution was 15g Oxy Bleach in 3 litres of warm water.  It may require up to a couple of days sunlight (in the UK) and some items took longer than others, so keep your eye on it.
 

Plastic cords
These tend to get greasy and attract dirt.  They are also hard to clean because they are spiral.  The best and easiest way to clean these cords is to submerge them in a solution of Biological Washing Liquid/Powder and leave overnight.

Paint should then peel off and any sludge on the cord can be brushed off.

Last revised: July 23, 2025