On 24/07/2019 10:36, Ian Jackson wrote:
In message , Jim S
writes
Andrew wrote in news:qh7i1c$vh0$2
@gioia.aioe.org:

On 23/07/2019 07:20, MrCheerful wrote:
On 23/07/2019 06:46, Rob Morley wrote:
On Fri, 12 Jul 2019 15:30:01 +0100
newshound wrote:

2004 Renault Master. Some of the online links suggest you have to go
back to 300 grit to remove enough material, can this be right?

When my car failed the MOT for having no discernible beam pattern
("We
can fit new ones for you ...") I decided to first thoroughly clean
the
lenses before getting stuck in with the wet and dry.ÂÂ* One of the
cleaners I had to hand was sugar soap, and to my surprise it
significantly reduced the haziness, such that a quick rub over with
metal polish had the beams nice and crisp.ÂÂ* I think the guys at the
garage were surprised to see me back so soon.


I see several different early Focuses with cloudy lights each year for
their tests, after a normal wash of the lights I use a lump of body
clay
and dilute detergent to clean them, then Mcguirs RX headlight polish,
they all respond well to this every year, and it is very quick to do.
What I do notice is that the residue of the cleaning has a green tinge
to it, so I wonder if it is some sort of algae that grows on the lens?

Someone on youtube swears by cleaning the plastic with wet-and-dry
ultra-fine grade then just covering the lens with clingfilm.

when that gets mucky, peel it off and stick some more clingfilm on.


I tried all sorts, but when my car came back from passing its MOT the
garage had cleared it using T-CUT and WATER. Should have asked them
sooner.

I would have thought that well-thinned T-Cut would work - and I guess
that Brasso or Silvo would work too.

Mine came up pretty well using standard domestic "cream cleaner". Using
a felt wheel on a variable cordless speed angle grinder I found it easy
enough to avoid melting by keeping the speed down and not using the
corner of the pad (on the Master there is plenty of "lens" that is just
over decorative chrome, so you can check your technique on this region).
But, the cheap pads are rather "bumpy" so it isn't very easy to do. I
finished them off by hand, but that was quite hard work.