'Yellowing' Headlight

[cyt]

Hi all,
Any idea what can be done to 'fix' a yellowing headlight glazing/screen for being over exposed to sunlight?
Thanks in advance

[NucMed]

Here's one method .......

http://forums.vwvortex.com/zerothread?id=2485084

[Lyntonius]

Whoa awesome. My headlights are a bit yellowed and it really shits me. I might have to give this a go; I thought the only option was to buy new ones.

[jessV3]

I need to do this as well, my head lights are very yellow .. but im not 100% convinced about the sand paper part, my brother did that once to one of his cars and it left small scratches?

[NucMed]

There's also some place (apparently) called Plastifusion in Sunnyholt Road Blacktown, NSW that does this sort of rejuvenation of plastic headlight covers.

http://austheadlights.com/home.htm

But I can't get it to work, comes up with some load of old cobblers about disable all your ad blocking features and use Internet Exploder .........

Cold day in hell .....

[jessV3]

Ok so I did this DIY today.. it turned out pretty good, I dont have have the haze completely out but there 100 times better and no signs of yellow at all.

Its pretty easy the only thing I changed was i used an electric buffer rather then doing it by hand because it was taking so long, it still took around 2 hours per head light, if i spent more time on it I probably could of got them perfect.

A few pics from my phone -

Before




After -

[Nero]

I need to do this as well, my head lights are very yellow .. but im not 100% convinced about the sand paper part, my brother did that once to one of his cars and it left small scratches?

Common practise on glider canopies and aircraft as well although it depends on how bad the scratching is. You need to start with something like 800 grit dry then wet and work your way up in grades to about 2400 or basically the finest stuff you can find. Then usually you finish off with brasso chews up plenty of hours though. For a reasonable result relatively quickly without sanding autosol metal polish is pretty effective but I wouldn't be using a buff on it. Old school glass headlights FTW

[NucMed]

The continued yellowing of my headlights is starting to irritate (in addition to safety concerns) and I've been looking around (as I can't find any actual restoration or exchange places) for other methods and have found this stuff called Pittman Original One Step ALR (acrylic lens restorer).

It claims you just need one drop of this stuff to fix a headlight lens and don't use wet n' dry (the chap on this site gets quite excitable about the evils of this and bangs on about caveman technology ......)

http://www.ibc34.com/Onestep.html

it is obviously using a chemical reaction as opposed to mechanical abrading to perform the job.

Has anyone ever used this?

Another one is Glassylite

http://www.glassylite.net.au

although with this, you still need to do the hard yards with the wet n' dry.

At the price, I might just buy both and start with the chemical reaction ....

[NucMed]

OK, I got the Pittman acrylic lense deoxidation stuff and applied it over the weekend (well, took 5 minutes per lense) and came up with this (I just did the whole pic thing as an afterthought, should have been more scientific I guess) ........

There are random areas on the lense that appear as if in its previous incarnation, someone has dripped some sort of chemical solvent on the lense and this appears not to be able to be deoxidised.

There are also areas that appear to have been sand blasted (or some sort of similar damage), could well be just that the lense are 10 years old, and judging from the rest of the car, has spent the bulk of its life outside, maybe parked on a beachfront.

The "sand blasted" areas also appear to be unable to be deoxidised. This fits in with what the guy from Pittman says .........

"If you used a machine buffer or an abrasive cleaner, cream, paste, sandpaper, or harsh chemical product on your headlight lens in a past effort to restore them, your lens cannot be fully restored. Your U.V layer has been damaged. The improvement will be noticeable but not 100%."

I'm unsure about this declaration re UV coating though, as most plastics such as polycarbonate attenuate UV and, at least in theory, would require no additional coating.

However, the damage done by UV to the plastic over time will go all the way through the plastic, but at that stage you would need to replace the lense (and probably the reflector too).

I'll see how long the effect of this stuff lasts for (Pittman's reckon somewhere between six months and two years) and post back.

I'm guessing, until the manufacturers get their acts together and produce better plastics for lenses we are going to be stuck with this sort of bodge to clean up the lenses.

I suspect, the ten years that have passed (at least with my car and the likely situation it has been in) since manufacture, is too long without some sort of remedial care for the lenses.

I'd like to see someone with just oxidation (not abrasion) damage use this stuff and report back.

Cheers, Peter

[jessV3]

looks good Peter, I am pretty sure Audi have already changed the plastic lenses that they used on our cars as the problem does not seem evident in even the later mode C5 A6's (01-04)

IMO the "yellowing lense" has only effected the following models-

A6 (97-01)
A3 (01-03)
A8 (01-03)
S8 (01-03)
A4 (99-01)