Best Product for dehazing headlights

[SkintKnuckles]

Hi all,

+1 for the 3M kit, as above. Also available on amazon (spit!):

http://www.amazon.co.uk/3M-Headlight.../dp/B0078IHJ1K

NB For this strategy, you WILL need a drill, ideally a corded one. Plan on 20 mins total time per headlight. You could go manually, but it'd take an age!

After you’ve obtained the desired finish – which should be like new – you need to use a UV stabiliser to ‘cure’ the finish. If not, the strong UV from the lamp will severely yellow the plastic of the lenses.

You can use the stuff shown below, which takes a further 2-3 mins per headlight.

http://www.amazon.co.uk/Surface-Seal...317101-8931140

See attached pdf for before/after.

The level of restoration is pretty satisfying, which is great as this is a cheap fix, and takes < 1 hour, all in. The photos don’t do justice to how bad the lenses were before. This is due to alcohols in the cleaning reservoir (which act as antifreeze) damaging the plastic of the lens.

Enjoy! Good luck

Cheers
Neil

[swedishandgerman]

Originally Posted by SkintKnuckles

Hi all,

+1 for the 3M kit, as above. Also available on amazon (spit!):

http://www.amazon.co.uk/3M-Headlight.../dp/B0078IHJ1K

NB For this strategy, you WILL need a drill, ideally a corded one. Plan on 20 mins total time per headlight. You could go manually, but it'd take an age!

After you’ve obtained the desired finish – which should be like new – you need to use a UV stabiliser to ‘cure’ the finish. If not, the strong UV from the lamp will severely yellow the plastic of the lenses.

You can use the stuff shown below, which takes a further 2-3 mins per headlight.

http://www.amazon.co.uk/Surface-Seal...317101-8931140

See attached pdf for before/after.

The level of restoration is pretty satisfying, which is great as this is a cheap fix, and takes < 1 hour, all in. The photos don’t do justice to how bad the lenses were before. This is due to alcohols in the cleaning reservoir (which act as antifreeze) damaging the plastic of the lens.

Enjoy! Good luck

Cheers
Neil

I was interested in your advice regarding the UV stabiliser. However, in the link you kindly provided it clearly says not for use on Polycarbonate!

I have to say that having done it with the 3M kit to make them really good only using the very fine grade then the wet pad, I still use some of the polish on the wheel every now and then just to keep the yellowness at bay.

All said, before I had the 3M kit - I won it in a raffle - I did the job extremely well with different grades of wet-and-dry starting from 1,500 grit and down incrementally to 2,000, 2,500 and finished with 3,000. Each time rubbing at right angles from the previous grade. Followed with a proper polish with metal polish then some normal car polish. It was time consuming, but as good a result as with the 3M kit which I've since used on another car.

[SkintKnuckles]

Hi Swedish,

you are absolutely correct! At the time of doing the Volvo headlights, I was to-ing and fro-ing about whether to treat the bulb or the headlight lens, as either approach should work. All you really need is a 'sunscreen' for the emitted UV light from the halogens.

In practice, I checked out the ingredients and could see no obvious reason why the stabiliser should affect the plastic lenses on the Volvo (I'm a physical-organic chemist by training). However, one could simply 'paint' the stabiliser onto the dipped and main beam halogens and get the same effect, but I was less sure about the thermal resistance of the stabiliser during cycling on hot bulbs. Thus, I just went ahead and used it on the lens and I've had no issues to date, and no yellowing. However, its good to be paranoid and careful about these issues. Well spotted

To be honest, the absolute worst thing you can put on these headlights is the concentrated windscreen wash solution. A bit of a design flaw in either the screen wash or the lens material methinks!

cheers
Neil

[Longhouse21]

Might sound a bit daft but I've used Autoglym SRP on the polycarb lenses on both a Mazda Demio (wife's old car) and a current Honda HRV run-about I use. The results on the Mazda where very impressive and made them look like new - even the wife commented! On the Honda it makes an improvement but I find I need to repeat it every 6 months or so. Reasoned that it's a fine polish with some filler ability and it works a treat on paintwork so couldn't see any real harm with the polycarb lenes.

[andylane1]

The 3M kit everyone is referring to above is fantastic but does need a Drill. You can pick up a cordless drill fairly cheaply nowadays. I do recommend the UV protection above as if you do not put some sort of protective layer on them they will start to yellow fairly quickly after. Autoglym have just released a new product which does the same as the 3M stuff and at the same price so I will try that on the Volvo. I used the 3M stuff and the UV Stuff on my Honda Accord, with Polycarbonate lenses and it did no damage what so ever. I've posted a link below to a video I put together when I did the Honda and as you can see the before and after is a huge difference with very little effort. I'll be putting another one together when I do the Volvo. Although I may remove the lenses when I do the Volvo as even with the masking tape I managed to scuff the paint on the bumper of the Honda and I don't want to do that on the Volvo.

Heres the link https://youtu.be/XcoWvVb5eFA

You can do it by hand with Wet/Dry sand paper (500-grit rough sanding, 800-grit fine sanding, 1200-grit wet sanding), a bucket and some T-Cut, Oh and some Elbow grease but the drill will cut down the time to about 30-40 mins a headlight.

Hope this helps
Andy

[Simon Jones]

Originally Posted by SkintKnuckles

...you are absolutely correct! At the time of doing the Volvo headlights, I was to-ing and fro-ing about whether to treat the bulb or the headlight lens, as either approach should work. All you really need is a 'sunscreen' for the emitted UV light from the halogens.

My understanding is that the biggest cause of UV damage is sunlight rather light from the bulb. If it were coming from the bulb then surely all the cloudiness would be on the inside of the lens? The headlights on my campervan go hazy even when parked up for a few months.

[SkintKnuckles]

Hi Simon,

for sure the lens will 'see' UV light from any source and the damage therein will depend on the relative intensity and duration of different UV sources.

Without getting a piece of the lens and checking its spectroscopic properties, its difficult to say how much UV light is transmitted through the lens (from the halogen) vs incident UV light hits it from the sun. Many plastics cut out >98% of UV light, but the remaining 2% can be quite damaging, especially from an intense, close up source like the halogens.

Thus, I'm agnostic on which is worse - incident sun UV vs emitted from the halogen. However, I do think the halogen is a very bright source, is very close to the lens, and likely to produce more intense UV than incident sunlight, for more hours per day (compared to the sun), at least up here in Scotland. However, if it turns out that the lens is made from a material that doesn't allow much UV light to transmit through it (i.e. from the halogen), then you would be absolutely right that, in this situation, environmental UV would determing yellowing rate.

If I had a spare lens or piece of one, I could get it measured so that we have a definitive answer to this, and where best to apply the stabiliser.... This is the science nerd in me raising its head!

cheers
Neil

[4candles]

Heat pan up to high heat, pour in some wine and..... oh thats deglazing,

[henrycrun]

Was told at last MOT that clear lenses are now a requirement.

Has anyone had such a failure ?

[raleigh753]

Had an advisory today on my MOT for both headlights - reduced output . Just ordered the 3M kit from Amazon as mentioned in the thread.