Car Head Light Restoration Guide

[Dr MUDHAN]

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To me, Head lights are the most beautiful part of a vehicle.

Dull, foggy, yellowish lens would make the car look ugly and will reflect how the car being cared by the owner.

Beyond the aesthetics, they perform worse, ruining the overall image of the vehicle, also have a safety hazard.

WHY DO HEADLIGHTS BECOME BLIND?

The modern vehicle headlight lenses are made out of high quality transparent plastic, acrylic materials (plexiglass) with a protective clear coat. They are designed to tolerate the optimum heat produced by recommended inner OE bulbs and outer natural environment.
The car is also constantly exposed to the sun, rain, car exhaust and all sorts of dirt, debris.

These would also expedite the deterioration :

1. Replacing with higher watt headlight bulbs.
2. Uncaring to protect the lenses during aftermarket painting job.
3. Cleaning it with poor quality, hard water.
4. Parking the car in open, very hot & in a dirty environment.
5. Affixing stickers, spraying harsh chemical color powders during festivals & paint thinner to clean the surface.
6. Internal condensation, water damage due to defective headlight assembly.

Plastic gets oxidized in UV radiation, the longer transparent plastic is exposed to the sun, the faster it becomes dull/yellow.



CAN WE RESTORE THE LENS?

Before carrying out restoration, please find out the condition and category in which the lens belongs:

Grade I
The age of the vehicle within 5 years, where the lenses are appearing not as new. The issue would be on the external layer.
Head light lens restoration may work good for Grade I vehicles.

Grade II
The age of the vehicle is around 10 years or more where the lenses are almost blind. The issue might be over both inner and outer layers.
The Grade II may require complete opening, detaching the lens from the head light assembly and cleaning both the inner and outer layers.
The damage caused while detaching the parts, resealing the butyl bond, and the expense incurred will all discourage us; make to go with a new one!
Go with such process unless it is difficult to get such OE / Aftermarket Headlights. Even if restoration is required only for the outer layer, mostly we would be 'fairly satisfied' with the result.

Grade III
Grade III refers to Very old, classic and vintage’ vehicles. Generally, their head light lenses are made out of glass. Glass won't oxidize, no matter how old they are. They could get dirty, but a good cleaning, would look like new.
In case of other than glass, we need to do the process meant for Grade II, as replacing with a new one would not be possible.


TOOLS REQUIRED:

• Clean Water with Car Shampoo (no carnauba wax) - Using water and sandpaper is also called 'wet sanding', is to lubricate, reduce friction, prevent accidental damage from heat buildup.
• Clay Bar- Not a must but a better initial process.
• Spray Bottle
• Microfiber Towels
• Isopropyl Alcohol - To degrease the surface, remove all the oils that remain on the headlights after the compound and polishing step.
• Masking Tape - Protect adjacent structures from accidental damages.
• Sandpaper 400/600/1000/2000 of Various Grit / May require a sanding drill Machine. We need to start with 400 grit until our headlight looks nice and hazy on the whole surface, to make sure no remaining yellowing, old plastic, old film, or clear coat before we go for the finer grit sandpapers.
• 2K Rubbing Compound for Manual Process or Heavy Cut /Soft Cut Compound with Soft /Coarse Pad & a Polisher Machine. If you do not have a polishing machine , then you can also do it by hand. but it takes much longer duration. Afraid of elbow grease ? You can get a headlight restoration kit that is used with a drill.
• AIO Cleaner
• Quality Ceramic Coating Liquid. This sealant creates a time capsule effect, preventing wear and tear to keep them looking pristine and crystal-clear for months–or even years. Avoid clear-coat paint, as it is not intended to work properly on plastic.

THE PROCESS
READ HERE (LINK) the experience of CRACING in our forum. Please also view the videos below.

• Aftermarket restoration/ Intervention is recommended only for those 'still young' lenses or where replacement is impossible. Otherwise, the process may not make those results long lasting against natural deterioration.
• Always replace with OEM Spare while replacing Old Headlights, as counterfeits will soon become yellowish.
• When replacing with aftermarket stylish headlights like projector ones, go with reliable brands for more longevity.
• Always insist for the 'removal and refit ' of all the lights during repainting / painting after accident. Note, covering with newspaper never serve the purpose.
• Always work out the cost of tools & labor involved before carrying out a DIY.
• Check before DIY / seeking professional help for complete restoration (both inner & outer) whether it is value for money - considering the age of the car / part for a defect free & a long lasting effect.
• Don’t be carried by product manufactures marketing gimmicks!
• Make sure, you apply acrylic plastic friendly compound whenever you try a new chemical.
• Avoid wrapping PPF as it would dull and tends to become yellow over a period of time.
• Please read and follow carefully the instruction process that should be carried out while sanding; the type of movements whether circular/horizontal/vertical based on the grit used and the pressure applied whether soft/medium or more required. Picking up the heaviest grit compound or sanding pad in a kit can strip away more of the headlight lens than necessary, cutting deep into the plastic and creating rough abrasions that can be difficult to smooth.
• In professional method they use 4 different sanding grids to remove hardest to fine residues; process 2 different stages of buff polishing. Note, Headlight restoration process doesn't vanish deep scratches/cracks.
• The need for repeat headlight restoration depends on exposure to elements and usage. Generally, restoring headlights every two years or when significant dullness or yellowing is observed is advisable.

INTERESTING VIDEOS:

PRODUCTS ONLINE

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[Dr MUDHAN]

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A WORD OF CAUTION DURING FESTIVE SEASONS: PROTECT THE HEADLIGHT LENS!

India is a land of festivals. It is better to avoid taking out the vehicle, but it is practically inevitable as most of us would prefer visiting family, friends and to the place of worship.

The commonly used synthetic colors or pooja powders like 'Kumkum' or so called 'Sandal Wood Paste' during festivals like Holi or Ayudha Pooja (Astra Puja / Maha Navami / Dussehra) are usually a blend of various chemicals like mineral oils, heavy metals and glass powder; these synthetic colors /stains are difficult to get rid off.
Applying any 'holy powder' during pooja over the Headlight lens is not advisable (may be okay over windshield).

Solution: Avoid as far as possible. Protect the lens with a layer of wax a day before pooja, remove those synthetic color powders as early as possible. Clean the lens surface with water & a plastic friendly liquid like Amway Car Polish / a good quality AIO polish.

Note: The headlight Lens is a tempered form of polycarbonate plastic that is inherently porous. To compensate for its porous nature, the headlamps are covered by a protective film. However, due to extended exposure to sunlight and UV rays, the films begin to degrade and the plastic becomes oxidized. Once the colored chemicals get into the pores, it would be difficult to remove.
EVEN
Avoid any stickers or so called 'antiglare' black spot or any dealer’s logo stickers over the head light lenses as the gum used behind is of low quality chemicals - may react and spoil the spot.

Take Care.

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[350Z]

Note: Thread now live. Thank you so much @Dr MUDHAN for sharing yet another incredibly useful thread.

Drive Safe,
350Z

 

[anuraagshenoy]

Condensation and Moisture entry or Water ingress was a major point of concern for me when I did the Morimoto HID retrofit way back in 2018 on my Creta.

Home-made oven to open the headlights


Placed the headlight inside to heat it to soften the sealant


Used a hot-air blower to heat the box


A thermometer to keep a check on the internal temperatures


Manual heating to soften further to separate the clear lens from the headlight casing


Almost separated


A fresh bead of butyl rubber added


After the butyl rubber bead was placed and the clear lens was pressed in place, these clips were used to hold and sandwich the clear lens and plastic body for a good and uniform seal


Morimoto Original butyl rubber used for the DIY


No condensation or water ingress


The DIY MOD was performed when the odometer was around 45,000 kms and the current odometer is 1.33L kms. Since then after multiple pressure washes and exposure to rain, I am happy that the headlights have been free of any condensation or water ingress during washes.

 

[Dr MUDHAN]

Condensation and Moisture entry or Water ingress was a major point of concern for me when I did the Morimoto HID retrofit way back in 2018 on my Creta.

Thanks for sharing your impressive DIY (Especially Home-made oven to open the headlights) to overcome Headlight condensation issues.

I have also dealt with Headlight condensation issues in an exclusive second part here:

Car Headlight Condensation – Issues & Solutions

Our forum members /visiting guests may also go through for details.

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[INDU]

Dr MUDHAN, Do you recommend such home made design of Heat Box ?

 

[Dr MUDHAN]

Dr MUDHAN, Do you recommend such home made design of Heat Box ?

Honestly, Yes & No!


YES :
If you know what you're doing!
Food grade Aluminum foil is very thin and weak, and it can't stop the heat from reaching the wrapped material, actually that helps here @ a vigilant and controlled environment when we monitor properly the process step by step / internal temperature.
Note: This works well on small/medium size headlights previously sealed with thermolabile sealants like Silicane, Butyl etc.,
Check this video:

NO :
1. If Permanent Sealant is used to seal the OE headlight; we really need to work more to detach the sealing by using a professional oven. It is harder than soft butyl, we need to put the headlamp into the real, professional oven to heat several times... through pry, bake, pry, bake…repeat method.

2. Due to fire hazard involved! One should not take the risk if he doesn't know what he is trying to do.
Due to the risk existing between Cardboard Box and the Blower. The Blower nozzle gets very hot; the hot plate grill inside a heat gun gets red hot & Cardboard is a combustible material. Aluminum foil is not flammable but it can melt at very high temperatures.
Note: Heat can travel in three ways: by Radiation, Convection, and Conduction.
Normal Aluminum foil can reflect some of the radiant heat, but it can't block the transferring and conducted heat, which are the main sources of fire.


Soon I will share more about : Baking car headlights!

Regards
Dr MUDHAN