Cloudy headlights

[Spike]

I've used this stuff for many years on the appropriate parts of my motorcycle:

A semi-gloss version is also available.

[newshound]

That looks useful, and not silly money, and claims to include a UV filter. I think I would still worry slightly that it might "attack" polycarbonate (in spite of saying safe on plastic).

I think I might be happier with this

[Spike]

My machine's 30 years old next year, and the plastic and rubber parts are just fine. The headlamp lens is glass but the other lenses are plastic and they are just as they came out of the factory. Armor-All is I believe water-based rather than VOC'd and has the appearance of cow's milk.

3M is a top company, I've done research using their materials; that product looks OK. My personal preference is not to abrade the lens surface but to use a UV filter/blocker and slow the deterioration.

[newshound]

Thanks, useful info. My problem is that it's a 15 year old vehicle that I have had for five years, it was already degrading when I got it. But, agreed, if I had treated it then I might still be OK now.

Just ordered a bottle of Armor-All, for after I've done some polishing.

[billyorange007]

And the British? (Not counting cars made in Britain by forign manufacturer)

[Rob Morley]

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. 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. I think the guys at the garage were surprised to see me back so soon.

[MrCheerful]

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?

[Andrew]

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.

[Jim S]

Andrew [e-mail] wrote in news:qh7i1c$vh0$2 @gioia.aioe.org:

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.

[MrCheerful]

I will try r=that on the next one that is convenient.

[Ian Jackson]

In message <XnsAA95CE0B8EDBjimjimXscottcouk@81.171.92.222>, Jim S [e-mail]> writes

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

[newshound]

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.

[Rob Morley]

But I'm sure they were grateful. ;-)

[newshound]

Just had delivery today of a disk with about 24 square felt pads around the rim, set overlapping (if you know what I mean). There are abrasive paper disks designed a bit like this too. From a quick trial on a spare piece of perspex, this looks as though it will be good on headlights.

[Harry Bloomfield]

Ian Jackson formulated on Wednesday :

Absolutely any fine abrasive polish will bring the lens up.

[Andrew]

There used to be something called 'Jewellers Rouge'

[Rob Morley]

There still is - I bought some on eBay a few months back. It's just ferric oxide in a very fine powder form.

[Harry Bloomfield]

Rob Morley pretended :

Absolutely any fine abrasive polish will work, including toothpaste. If the lens is in really poor condition, then begin with a fine wet and dry paper, plus water. Don't use a drill or similar, except slowly with water spray to keep it cool. Polycarbonate is easy to melt with too much heat from friction.

There is still the problem of once they are clear and sparkely, they will not remain that way for long, once the UV gets at them. They are obviously protected by some means when they leave the factory, but that wears of eventually. The best idea I have heard suggested spraying them once polished up, with the clear lacquer as used on car paint work.

I have never had the courage to risk my lenses with that, but has anyone tried it? What does the panel think?

[Peter Hill]

The advice was never paint a polycarb crash helmet.

Followed by never put stickers on polycarb crash helmets.

The reason being that you can never tell what solvents are in the paint or glue and what effect they have on polycarb.

[newshound]

Polycarbonate is quite sensitive to environmental stress cracking when exposed to polar solvents. Headlamp recovery kits typically come with a UV resistant lacquer that is presumably compatible.