Any plastics experts here please?? - Petel
Seasons Greetings to all. I have a Fiat Panda, on which several of the black plastic external pieces have turned a grey colour, where they are exposed to the elements. Can anyone please advise what causes this and what can be done to prevent/cure it?

When washing the car, the water makes the parts go black but as soon as the water dries off, they are back to grey. I assume that this is down to the type of plastic used, to age and to exposure to sunlight, as the areas of the parts not exposed, have retained the original black colour.

I am aware of Back to Black and other products but these only disguise the problem for short periods. I seek to establish what causes this problem and how to prevent it occuring in the first place.

Thank you, petel
Any plastics experts here please?? - SjB {P}
I seek to establish what causes this problem and how to prevent it occuring in the first place.

Park the car in a garage with no windows and don't use it!

As you guessed, atmospheric conditions and UV light age the plastic. You can't stop this. You can only disguise it by use of products like you mention, some of which work better than others.
Any plastics experts here please?? - Roberson
Once black body parts like this have aged, you can't do much with them, apart from 'disguise' the 'problem'.

I would recommend Autoglyms Bumper Care. It still washes off eventually, but is not as messy as the black gunk which is sometimes called bumper black. You can also try Armorall, which is cheaper and can be used to beautify rubber and plastic, inside and out. Available from Wilkinson?s.

The front bumper on my Polo was so far gone, in terms of colour bleaching that the only real alternative was replacement.
Any plastics experts here please?? - steveo3002
try liquid shoe polish..the stuff in a little bottle with a foam applicator, make sure its stated for "scuff cover"

alot of people with golf gti's use it..lasts ages and doesnt come of on your clothes or anything bad

cant beat t for £1.99
Any plastics experts here please?? - Simon
I also recommend the Autoglym Bumper care. Its one of the better products on the market that I have found but none of them are foolproof. Once the plastics have got to this stage then all you are doing is disguisng the problem and after a few washes it soon fades back to grey.
Any plastics experts here please?? - Oz
The problem is caused mainly by UV in sunlight degrading the surface so it's no longer glossy - same as can happen with paint. Likewise as with paint, some plastics are more exterior-durable than others.
The answer is as above - replace the surface layer. Then it's down to how durable the replacement layer is, and how good the adhesion to the original plastic is.

Oz (as was)
Any plastics experts here please?? - bell boy
go on then i will tell you a trade secret,i use a heat gun to bring back the colour on faded plastic bumpers/exterior trim,if you keep the gun moving you will see the black restore in front of your eyes be careful and i dont really recommend the treatment if the article has a mottled effect as you can lose part of the finish.When done protect with a plastic restorer to cut down on the u/v .
This treatment is very effective on mk1 corsa wheel spats it turns an unsaleable motor into a must have.(no conpensation claims will be entertained if you ruin anything mind )
Any plastics experts here please?? - Petel
Thank you all for your replies, the input is much appreciated. Special thanks to you "Oldman" for the trade tip, which I will try at the first opportunity. I now learn, that some of these plastics are classed as "UV stable" and others are not. The search continues.
Thanks again to all. petel

Ask Honest John

Value my car