restoring yellowed headlight lens

[skyline_400r 0]

Does any1 know how to restore cloudy headlight lens? I want to get rid of that yellowed foggy lens and get it back to the original condition

or any1 knows where i can get the job done in auckland?

Cheers

[JiB 2]

Is the yellowing on the outside or inside?

Meguires PlastiX works well. But obviously some work involved if on the inside.

[greenday-rulz21 6]

Theres this kit Supercheap is selling which I've been trying to find for the last couple of months. Always sold out so it must be pretty good, yet to try it though.

[skyline_400r 0]

i think it's a bit of both inside and outside actually

any shop in auckland that do these kind of job?

Edited June 24, 2008 by skyline_400r

[skyline_400r 0]

was searching in yahoo and found something called Plexus

it's a plastic polish bikers use to polish their light lens

don't know if that will work on my headlights or not?

any1 tried?

Edited June 24, 2008 by skyline_400r

[Braeden320 0]

Headlights on my old car were cloudy/yellowy when got it to.

I used some really hard cut and polish on them - they came up mint.

[jjs 64]

You will be amazed at how good a job Jif and elbow grease will do.

I once failed a warrant due to yellowed lenses and was told I would need to buy a new headlight. But, after scrubbing them with Jif for nearly half an hour, my headlights were like new

[Apex 693]

You will be amazed at how good a job Jif and elbow grease will do.

I once failed a warrant due to yellowed lenses and was told I would need to buy a new headlight. But, after scrubbing them with Jif for nearly half an hour, my headlights were like new

Good tip, haven’t heard that one before! I was told to use a metal polish but can recommend no one tries it as I wrecked my headlight!

As said a light cut like T-CUT should do a good job followed up with a polish. The key ingredient is elbow grease.

Im keen to try that Plastic X from Meguiars as their scratch X for body work is fantastic.

[Palazzo 479]

If it's the same stuff (Meguiars) that you use on convertible (plastic) windows, it works great. Took all the yellowing out and most scratches. If the lenses are plastic, should do the same.

[Apex 693]

If it's the same stuff (Meguiars) that you use on convertible (plastic) windows, it works great. Took all the yellowing out and most scratches. If the lenses are plastic, should do the same.

Knowing Meguiars they will have five products the same in five different containers targeting 5 different markets.. Their range is massive!

Edited June 25, 2008 by Apex

[skyline_400r 0]

"5 products the same in five different containers"

LOL

[Apex 693]

Sorry I should have wrote, they have the same product in five different containers.. I didn’t do well at school

[pjay 8]

meh made sense to me. ive just cut and polished my yellowy headlights in older cars with that repo stuff in the red can. worked fine.

just keep scrubbing, just keep scrubbing, just keep scrubbing

[elmarco 56]

Are they the Bosch OEM lights? I'm assuming they are for your E46?

The ability to polish the yellowing/fogging out may be dependent on the reason it has discoloured in the first place. Clear polycarbonate will yellow with UV exposure unless it is coated (OEM lenses are, but some cheap aftermarket ones don't get the same treatment). If it is just road grime you might be OK. If it is inside the lens or there is any melting, you have a whole other problem - like high wattage bulbs overheating the lens or reflector problems.

Don't use any agressive chemicals to clean them - PC is very sensitive to chemicals like alcohols, MEK, fuels etc and will dissolve or stress crack in front of your eyes if you hit the right combination... You can use normal car polish - works wonders with acrylic lenses (normally only used on side and rear lamps), and although it doesn't work as well with PC you may still get a result with it polishing any grime off. Also be aware that PC is actually relatively soft so agressive polishing can cause permanent scratches - I wouldn't use Jif as it is too agressive.

Glass lenses should be OK with normal glass cleaners/polishes - standard E46 headlamp lenses are polycarbonate not glass though.

Good luck!!

[elmarco 56]

Forgot to add that E46 headlamps, like all new vehicles, are glued together. Not sure if it is hotmelt or a 2 pot glue in this case - but it may not be possible to ever get the lens off in one piece. Heating it off could warp the housing or the lens.

[skyline_400r 0]

yes, they are for my e46

i reckon i might b able to fix the headlights

but i m not sure about the side markers

i don't think the lens can b taken apart?

is there anything that i can dip the side markers into to clean the yellowing?

[Apex 693]

I did mine with glass cleaner.. Maybe isopropyl alcohol., just don’t get it on the paint.

Maybe get some new ones?

Where the hell has your E46 been mate, seems like a fair whack of corrosion.

[Nobimmer 694]

If you can get into it just use an abrasive rubbing compund eg RUB IT or anything else. Will be a bit dearer but will use very little elbow grease.

Also agree that Jif works fine.

[JiB 2]

If a cutting compound is used, remember to use a protectant after. Because a cutting compound may make it look like new...but that's because it's just exposed a fresh layer of headlight to the elements.

Used Autosol on a mate's car...no-garage + summer sun + 3 weeks = back to square one.

[Apex 693]

Good point

I wouldn’t recommend Autosol, its to abrasive and scratches the plastic.

[elmarco 56]

I did mine with glass cleaner.. Maybe isopropyl alcohol., just don’t get it on the paint.

Maybe get some new ones?

Where the hell has your E46 been mate, seems like a fair whack of corrosion.

Just remember that the E46 lenses (like most new cars) are polycarbonate not glass. Polycarbonate is one of the most sensitive plastics to chemical attack and this is well known in the plastics industry (especially in the automotive lighting industry). I have seen PC lenses crack in windscreen washer fluid (containing methanol), and completely dissolve in commercial truck wash.

http://en.wikipedia.org/wiki/Polycarbonate

If you can get into it just use an abrasive rubbing compund eg RUB IT or anything else. Will be a bit dearer but will use very little elbow grease.

Also agree that Jif works fine.

You'll be sorry...... Anything that will scratch stainless steel will scratch your lenses.

[Yuen 16]

elmarco, do you know if the lenses have some sort of UV coating (or some other type of coating) on the front of the glass? I read somewhere that they did. And if we polish the lenses it takes away the coating which leads to some sort of detrimental effect. I'm not sure if this is the coating that results in some cars' headlight lenses giving off a rainbow effect when you look at it at certain angles?

[skyline_400r 0]

so..... is Meguires PlastiX save for my e46 lens??

[elmarco 56]

elmarco, do you know if the lenses have some sort of UV coating (or some other type of coating) on the front of the glass? I read somewhere that they did. And if we polish the lenses it takes away the coating which leads to some sort of detrimental effect. I'm not sure if this is the coating that results in some cars' headlight lenses giving off a rainbow effect when you look at it at certain angles?

I don't know for sure (never worked on any BMW projects) but I would be very very surprised if they aren't coated (this is the standard for PC headlamp lenses). The coating is normally used for UV protection (clear PC will go yellow with UV exposure without protection) and for scratch resistance (it is really strong, but also relatively soft). From memory the product normally used by the lighting guys is called lensguard (not something you can get from Repco). There are a lot of older Altezza's running around with UV yellowed headlamps and Toyota are a little bit sensitive about the subject now....

If skyline_400r's lenses are yellow all over and it is consistent (except where it is covered by the bonnet), it is likely to be UV fading and there isn't much you can do. If it is just a build up of road grime, then it may come right after the scum is taken off the surface (if this is the case, the entire front end will likely be filthy...). I guess it could also be corrosion of the aluminised reflector (the reflector material can be a yellowish colour before coating), but that would be pretty obvious.

Although they are coated, this is not normally protection against harsh abrasives (like rubbing with jif etc) - it is designed for normal car wash machines and domestic car polish etc (but not prolonged rubbing - especially with an abrasive). If you break the coating there is a chance it will start to flake and peel like any paint when the surface is broken. Course, when you break the surface, the natural PC is exposed underneath, and will start to yellow. Note: the yellowing process normally takes years (not months) and we have unusually harsh UV in this country - so it isn't something that you will see overnight.

I think the other guys are referring to glass lenses which are much harder and can be polished etc with jif and other abrasives (I think even the E36 lenses are glass). Not sure about the rainbow colours, but it is entirely possible this is the reason.

so..... is Meguires PlastiX save for my e46 lens??

Have never come across that particular product - I would just give it a go with normal car polish (Turtle Wax or similar) initially as they are designed for normal domestic use and car care. But don't put more elbow into it than you would normal paintwork... This should take normal grime off.

If it doesn't change, and the yellow is more like some of the Altezza headlamps (consistent in colour over all exposed areas - a diluted piss colour!) you may have to replace the lamps. In this case, I guess you have nothing to lose by getting stuck into them, but I would be careful if you don't want to end up replacing them.

You mention the side repeaters too. Are these the problem, or is it just the headlamp lenses? You aren't talking about the standard amber indicator lenses are you?? These are an amber plastic - you can't change the colour unless you replace the entire lamp.

Can you post photos of the issue?

[Yuen 16]

I don't know for sure (never worked on any BMW projects) but I would be very very surprised if they aren't coated (this is the standard for PC headlamp lenses). The coating is normally used for UV protection (clear PC will go yellow with UV exposure without protection) and for scratch resistance (it is really strong, but also relatively soft). From memory the product normally used by the lighting guys is called lensguard (not something you can get from Repco). There are a lot of older Altezza's running around with UV yellowed headlamps and Toyota are a little bit sensitive about the subject now....

If skyline_400r's lenses are yellow all over and it is consistent (except where it is covered by the bonnet), it is likely to be UV fading and there isn't much you can do. If it is just a build up of road grime, then it may come right after the scum is taken off the surface (if this is the case, the entire front end will likely be filthy...). I guess it could also be corrosion of the aluminised reflector (the reflector material can be a yellowish colour before coating), but that would be pretty obvious.

Although they are coated, this is not normally protection against harsh abrasives (like rubbing with jif etc) - it is designed for normal car wash machines and domestic car polish etc (but not prolonged rubbing - especially with an abrasive). If you break the coating there is a chance it will start to flake and peel like any paint when the surface is broken. Course, when you break the surface, the natural PC is exposed underneath, and will start to yellow. Note: the yellowing process normally takes years (not months) and we have unusually harsh UV in this country - so it isn't something that you will see overnight.

I think the other guys are referring to glass lenses which are much harder and can be polished etc with jif and other abrasives (I think even the E36 lenses are glass). Not sure about the rainbow colours, but it is entirely possible this is the reason.

Mm I get what you mean about the Altezzas, there are a fair few around. E36 lenses are glass. Btw I made a typo when talking about glass having the UV coating - I didn't think the glass would yellow from UV, only polycarbonate I assume...

I think PlastX is worth a go - note they changed the formulation sometime ago, the old one could only be applied by hand but the new one can be applied by hand or machine. It was a while back though so all shops probably have the new stuff now.

I know member 'mtk540' used the Mothers version of the plastic cleaner (sorry don't know the name) on his E39's pre-facelift lights which should be made of the same material - they were hazy/scratched. He reported success with it and you could see a change straight away on the first pass.

He didn't say they were yellowed though, so hopefully the yellowing on yours is only on the surface.

Good luck!