Polishing headlights

grazza · Postby **grazza** » Fri Jul 17, 2009 7:51 am

Hi all,
Does anyone have a surefire way to restore the plastic headlight cover? I have tried a number of products but they still tend to show swirl marks and dont "gleam" like a hoped they could. I have used Brasso successfully in the past on other vehicles but its not working so well on my NB8A headlights.

thanks

RawSouth · Postby **RawSouth** » Fri Jul 17, 2009 9:15 am

Ive used Maguires plastic polish on my 8B...

It seems to work pretty well, but I have to redo it every few months (its not too bad, it reminds me to put some more RainX on too

)

Hammer · Postby **Hammer** » Fri Jul 17, 2009 12:11 pm

x2 on the Maguires stuff.

Also check this link. The entire process is not about polishing, but parts of it is. It might give you some hints and tips.

Alex · Postby **Alex** » Fri Jul 17, 2009 1:00 pm

yea depends how bad it is, if it's just haze then polish should work fine, if it's got a cracked surface as well then sandpaper will be required.

Mr Morlock · Postby **Mr Morlock** » Fri Jul 17, 2009 5:59 pm

This subject has been raised a number of times. The lenses are moulded from polycarbonate (PC) and are hardcoated and the Japanese usually spray the hardcoat. The purpose of the hard coat is durability- without the coat the lenses deteriorate very fast and will crack and fail. To restore the lenses any gentle auto polish will be quite effective unless they are already in a very poor state. The Meguiars product will work.
I shudder at using Brasso - it is a ancient metal polish and not designed for plastic. PC can have reactions to some products ie like stress cracking. Wet and dry is a definite no no - it will remove too much of the hard coat and shorten the life of the unreplaceable lense. Look around at various cars and see lenses which are milky to see what happens without a little care.
Incidentally taillight lenses and repeaters are moulded from acrylic ( pmma) and these are not hard coated and the reason is that pmma has excellent durability though no where near the impact strength of polycarbonate. Each material in the car is selected by the engineers for a specific purpose.

Alex · Postby **Alex** » Fri Jul 17, 2009 6:11 pm

if you've got to the stage that the lights are very cloudy then any coatings are already broken down.
Wet and dry is the most effective way to get rid of the small surface cracks that appear on the top layer, or you could spend hours trying to polish it out.

grazza · Postby **grazza** » Fri Jul 17, 2009 6:45 pm

Thanks guys.
I have bought some Meguiars plastic polish (did not realise there was such a thing)
I have given it a trial and it has helped but it will need to give it a few applications.

There is a lot of references to using Brasso for polishing a lot more than brass, especially around boats. I have used it successfully on heaps of things with no adverse effects.

Mr Morlock · Postby **Mr Morlock** » Sat Jul 18, 2009 1:01 pm

you can only provide advice hopefully based on some experience. Wet and dry is wrong for plastic headlamps- you do not want to remove the hard coat merely "polish" it. I never cease to be amazed at people using the wrong products without doing any research. Examples are like using brake fluid to remove paint. Many plastics are adversely effected by some cleaners and you may find out only after making the wrong choice- best to read labels. Brasso has been around for probably 50 years maybe more and many materials have changed in that time so I use it for brass.