At nearly 30 years old, and probably past its design life, some parts of the BX show their age. One of the more notable areas is the grey plastics of the Citroën BX wing mirrors. I’m pretty confident they are meant to be black, but what is the best way to tackle restoring them.
Citroën BX plastics, fade to grey
There are many solutions to restoring late 80’s plastics. Ultimately the UV has caused the outer polymer bonds to break down, resulting in increased refraction of light and making the mirrors appear optically lighter in colour. Well, that’s my understanding. Different plastic types, mixtures and processes, and UV stabilisers help reduce the effect, but ultimately, fading is unavoidable on a car this age.
Restoring with a liquid treatment
There are a couple of methods of restoring the ‘black’ appearance. All are effectively trying to seal off the broken polymer chains to stop the reflection of the light, which causes the grey appearance.
First up is the fluid surface treatment. Nearly always containing silicone, these treatments usually work after a fashion, but not for particularly long. I’ve had this ‘Turtle Wax – Back in a Flash‘ taking up shelf space since getting it free with a house purchase. I’ve no idea how old it is, but it has a website address, so it’s not as old as the car! Let’s give it a whirl.
The whole wing mirror took about a pea-sized blob, applied with an old but clean cloth. Some areas took a bit more force to get into the texture of the housing. I probably should have washed/prepared the mirror a little better. It’s still a bit light in places and far shinier than I would have liked. Perhaps I should have read the instructions, which do say how to avoid the glossy finish. Oops.
It’s an okay result, it hasn’t cost me anything, and it’s about what I expected. I think it will be interesting to see how long the colour and shine hold up, it’s warm and sunny right now, but a biblical storm is probably on the way to the UK.
Application of fire
The second method for restoring the Citroën BX wing mirrors is the application of fire. And I am totally serious, but partly because I know I have a spare mirror for the driver’s side. Applying heat to bring the plastic to its, erm, plastic limit, will allow the surface to change its composition. I’m not sure if the broken polymer strands ‘fall’ into the good plastic behind or simply bond back together.
Okay, I admit it, I’m not brave enough to use a naked flame. I use a heat gun. A word of warning, you need an even application of heat within a small temperature range (far lower than the flame temperature). A little too much heat, and you’ll lose definition resulting in the part looking smooth forever. A bit more than that, and the housing will start to droop and deform. Keep going, and the fire brigade will nip round and give you at least a half-hour of not-exactly-gentle ribbing.
The end result is closer to what I want, but still not quite a new-car appearance. The consistency of the finish is variable because there is only so much winding up I can take from the fire brigade in one lifetime. The final colour is better than the silicone ‘wax’ approach, and from experience, should last quite a bit longer.
A note of caution. Heat application doesn’t work on the section directly against the door, nor the door handles. The section against the door is filled with reinforcement in the plastic (probably glass) and will just burn. I’ve tried the door handles, and with just-less-than-paint-destroying temperature, there is no colour change.
As usual, when trying to cover over grey at 30 something years old, you can give the appearance of youth for a little while, but ultimately the grey will show back through, and the time between reapplication will get shorter and shorter. Good job that I’ve got a whole bottle of ‘Black in a Flash’ to get through!