How to repair cloudy headlamps.
Most Mercedes-Benz headlamp lenses from 1996 onwards are plastic or to be
more accurate acrylic. Great idea as they no longer crack when a rock
flies up and hits them. The down side however is that on cars that spend
most of their time outside the headlamp lenses go cloudy.
The reason for this is that being acrylic them will get brittle when
exposed to the UV rays from the sun, so they have a UV protective coating
on them to stop this. Kind of like us putting sunscreen on when outdoors.
It is the breakdown of this UV coating that makes them look cloudy and
loose there efficiency for lighting your way after dark.
To repair this correctly there are two solutions, new headlamps as on
most of them you can't buy the lense as a separate part. Or you have to
remove the UV coating and reapply it. As you can imagine one solution is
far more cost effective. MB Spares sells a kit with all the gear you need
to carry out the low cost solution.
There are also a range of polishes on the market that just attempt to
polish the damaged coating, these don't work and infact damage the
lenses. This is explained further below.
The steps to repair the lenses are as follows:
- Remove from vehicle, or tape around surrounding panels.
- Use supplied cleaner to wash lense. You do not want any dirt on it
when you start the next step.
- Use 400 grit wet and dry sandpaper and remove all of the old coating,
you will know when you have got down to the acrylic of the lense when you
get a white milky residue from sanding.
- Now you need to get rid of the 400 grit sanding marks, so you need to
use 800, 1000, 1500 and then 2000 grit paper to get the marks out as you
go up each grit size the lense will start to get clearer.
- Then you polish the lense with the supplied polish, now it will start
to look reasonably clear.
- Then and only then can you reapply the UV coating which will totally
restore the lense to look like new.
- Leave to dry for 4 hours and reinstall to vehicle or remove tape.
As you can see the most important part of the instructions is the removal
of the old coating, if you just use a polish it just tries to polish up
the old coating and this does not work. The sanding process will take at
least 30 minutes per headlamp, maybe longer on badly affected headlamps.
The sprinter headlamps in the pictures to the right took us over 2 hours
from start to finish.
If you would like to purchase the headlamp restoration kit please
contact our parts department or if you would like us to repair your
contact our service department.