Headlight Restoration
Thread Starter
Super Member
Joined: Nov 2003
Posts: 880
Likes: 4
From: Ponte Vedra Beach FL/ Hampstead, London, England
'84 380 SL/ '02 XK8
Headlight Restoration
Lexan® Polycarbonate
In the late 1980’s, vehicle manufacturers changed the lighting lens system materials used for head lights from glass to a polycarbonate. Original equipment manufacturers (OEM) needed a material that could be moulded to aerodynamic shapes and was lightweight.
A polymer material, Lexan® Polycarbonate, which was both lightweight and could be moulded into many different shapes aerodynamic shapes, making it suitable for sports cars.
Is a registered trademark of SABIC Innovative Plastics; a highly durable polycarbonate resin thermoplastic intended to replace traditional glass and Plexiglas where the need for strength and impact resistance justifies its higher cost.
Vehicle Head Lights
To the naked eye one cannot tell that these plastic lenses are actually a porous material that expands ever so slightly when it gets hot. Degradation of the lens occurs over time. Having your headlights on or being exposed to the heat of the day causes the pores to open allowing debris from the road to get in.
Oxidation debris, together with a combination of environmental factors such as the ultra violet (UV) and heat radiation, smog, acid rain, car exhaust, and harsh chemicals used to wash the vehicle car can cause the plastic headlight lenses to become opaque. High Intensity Discharge (HID) bulbs also contribute to the deterioration of the polycarbonate lens as they emit ultra violet (UV) radiation.
Headlights are usually made from Polycarbonate; it has its advantages (light weight, easily formed to differing aerodynamic shapes, etc) but also has its disadvantages;namely oxidation / discoloration or more correctly photo degradation
Tail light, turning and signal (turn indicators) are usually made from heat and impact resistant acrylonitrile butadiene styrene (ABS)
Oxidation (photo degradation) - of the polycarbonate headlight causes it to dry out the plastizers and become cloudy or take on a yellowish tinge. Ultraviolet (UV) rays from the sun also cause the lens to develop micro-cracks, hastening the colour change. This debris can be removed with a chemical paint cleaner (Klasse AIO or Werkstat Prime Strong)
Surface damage - when the lens starts to exhibit an opaque appearance and then a yellow hue on the outside of the lenses, this is due to ultra violet radiation (UV), which also causes micro-cracks. Road grit / debris and harsh chemicals cause surface scratches. This can severely restrict the amount of light reaching the road and this becomes a safety issue as you rely on the vehicles lighting system to see what’s on the road ahead and adjust your driving accordingly.
1. Tape-off all around the lenses so that you don't accidentally wet sand or buff the surrounding areas.
2. Using a random orbital buffer with a 3.5-inch backing plate and a 4-inch (Lake Country (LC) Mfg) White polishing pad or a terry cloth applicator
3. Place a small dab (about ½-inch diameter) of plastic polish on the foam pad or applicator.
4. Place the pad on the lens surface and turn on the machine (speed #4)
5. Polish the lens repeatedly in a left-to-right and an up and down pattern.
6. Continue polishing until all the polish is gone
7. Wipe the lens with a damp Microfiber towel
8. Inspect the lens; repeat the polishing process 2-3 times as necessary
9. Finally wipe down the headlight surfaces with isopropyl alcohol (IPA) or a tack rag to eliminate any residue.
Notes –
1. Polishing or wet-sanding will not remove clarity defects that are within the plastic but it will remove external/surface scratching and ultra violet (UV) oxidation (yellowing) as well as OEM applied UV protection that should be replaced
2. Softer polycarbonate resists breakage but will oxidize faster.
3. Don’t use abrasive or highly alkaline cleaners.
4. Never scrape the sheet with squeegees, razor blades or other sharp instruments.
5. Don’t clean Lexan® Polycarbonate products in the hot sun or at elevated temperatures as this can lead to staining?
Original equipment material (OEM) suppliers started to add ultra violet resistant (UV) coating to the surface of the lens in an attempt to reduce this condition and prolong the usable life of the lens. This protective coating is very thin (25 µ (microns or 1 Mil)
Removing oxidation or scratches from vehicle headlights or brake lights (also polycarbonate) also removes the OEM ultra violet protection, which prematurely decreases the durability of the lens. Surfaces that have yellowed are a sign that the ultra violet (UV) sacrificial coating has failed and must be resurfaced and recoated.
Ultra Violet Protection - polishing or wet-sanding headlights without renewing their ultra violet (UV) protection is a false economy, unless this protection is replaced, the end result is that you'll have to do them again in a few months (repeat this polishing process enough and there will be no material left to work with)
In order to restore the lens back to its OEM standards a new ultra violet (UV) resistant coating must be re-applied. Use Optimum Opti-Coat™, which will provide ultra violet (UV) protection, the ultra violet (UV) absorbers are very durable and exhibit a 5 year half life, meaning that every five years the concentration is reduced by 50% percent, a 2-4 µ (microns) film and a hardness of 9H (Pencil Hardness) when fully cross-linked and provides a semi-permanent coating.
Relevant Articles
1. “Environmental Damage” - http://www.autopia.org/forum/car-det...l-damage.html#
2. “Nanotechnology coatings “- http://www.autopia.org/forum/autopia...-products.html
3. “Oxidation or Clear Coat Failure?” - http://www.autopia.org/forum/autopia...t-failure.html
In the late 1980’s, vehicle manufacturers changed the lighting lens system materials used for head lights from glass to a polycarbonate. Original equipment manufacturers (OEM) needed a material that could be moulded to aerodynamic shapes and was lightweight.
A polymer material, Lexan® Polycarbonate, which was both lightweight and could be moulded into many different shapes aerodynamic shapes, making it suitable for sports cars.
Is a registered trademark of SABIC Innovative Plastics; a highly durable polycarbonate resin thermoplastic intended to replace traditional glass and Plexiglas where the need for strength and impact resistance justifies its higher cost.
Vehicle Head Lights
To the naked eye one cannot tell that these plastic lenses are actually a porous material that expands ever so slightly when it gets hot. Degradation of the lens occurs over time. Having your headlights on or being exposed to the heat of the day causes the pores to open allowing debris from the road to get in.
Oxidation debris, together with a combination of environmental factors such as the ultra violet (UV) and heat radiation, smog, acid rain, car exhaust, and harsh chemicals used to wash the vehicle car can cause the plastic headlight lenses to become opaque. High Intensity Discharge (HID) bulbs also contribute to the deterioration of the polycarbonate lens as they emit ultra violet (UV) radiation.
Headlights are usually made from Polycarbonate; it has its advantages (light weight, easily formed to differing aerodynamic shapes, etc) but also has its disadvantages;namely oxidation / discoloration or more correctly photo degradation
Tail light, turning and signal (turn indicators) are usually made from heat and impact resistant acrylonitrile butadiene styrene (ABS)
Oxidation (photo degradation) - of the polycarbonate headlight causes it to dry out the plastizers and become cloudy or take on a yellowish tinge. Ultraviolet (UV) rays from the sun also cause the lens to develop micro-cracks, hastening the colour change. This debris can be removed with a chemical paint cleaner (Klasse AIO or Werkstat Prime Strong)
Surface damage - when the lens starts to exhibit an opaque appearance and then a yellow hue on the outside of the lenses, this is due to ultra violet radiation (UV), which also causes micro-cracks. Road grit / debris and harsh chemicals cause surface scratches. This can severely restrict the amount of light reaching the road and this becomes a safety issue as you rely on the vehicles lighting system to see what’s on the road ahead and adjust your driving accordingly.
1. Tape-off all around the lenses so that you don't accidentally wet sand or buff the surrounding areas.
2. Using a random orbital buffer with a 3.5-inch backing plate and a 4-inch (Lake Country (LC) Mfg) White polishing pad or a terry cloth applicator
3. Place a small dab (about ½-inch diameter) of plastic polish on the foam pad or applicator.
4. Place the pad on the lens surface and turn on the machine (speed #4)
5. Polish the lens repeatedly in a left-to-right and an up and down pattern.
6. Continue polishing until all the polish is gone
7. Wipe the lens with a damp Microfiber towel
8. Inspect the lens; repeat the polishing process 2-3 times as necessary
9. Finally wipe down the headlight surfaces with isopropyl alcohol (IPA) or a tack rag to eliminate any residue.
Notes –
1. Polishing or wet-sanding will not remove clarity defects that are within the plastic but it will remove external/surface scratching and ultra violet (UV) oxidation (yellowing) as well as OEM applied UV protection that should be replaced
2. Softer polycarbonate resists breakage but will oxidize faster.
3. Don’t use abrasive or highly alkaline cleaners.
4. Never scrape the sheet with squeegees, razor blades or other sharp instruments.
5. Don’t clean Lexan® Polycarbonate products in the hot sun or at elevated temperatures as this can lead to staining?
Original equipment material (OEM) suppliers started to add ultra violet resistant (UV) coating to the surface of the lens in an attempt to reduce this condition and prolong the usable life of the lens. This protective coating is very thin (25 µ (microns or 1 Mil)
Removing oxidation or scratches from vehicle headlights or brake lights (also polycarbonate) also removes the OEM ultra violet protection, which prematurely decreases the durability of the lens. Surfaces that have yellowed are a sign that the ultra violet (UV) sacrificial coating has failed and must be resurfaced and recoated.
Ultra Violet Protection - polishing or wet-sanding headlights without renewing their ultra violet (UV) protection is a false economy, unless this protection is replaced, the end result is that you'll have to do them again in a few months (repeat this polishing process enough and there will be no material left to work with)
In order to restore the lens back to its OEM standards a new ultra violet (UV) resistant coating must be re-applied. Use Optimum Opti-Coat™, which will provide ultra violet (UV) protection, the ultra violet (UV) absorbers are very durable and exhibit a 5 year half life, meaning that every five years the concentration is reduced by 50% percent, a 2-4 µ (microns) film and a hardness of 9H (Pencil Hardness) when fully cross-linked and provides a semi-permanent coating.
Relevant Articles
1. “Environmental Damage” - http://www.autopia.org/forum/car-det...l-damage.html#
2. “Nanotechnology coatings “- http://www.autopia.org/forum/autopia...-products.html
3. “Oxidation or Clear Coat Failure?” - http://www.autopia.org/forum/autopia...t-failure.html
Senior Member
Joined: Mar 2011
Posts: 277
Likes: 0
From: Nebraska
2005 CLK500 cab, 2004 S600 designo mocha
You mention Opti-coat as one product to protect headlights. Any other proven alternatives that you would recommend?
To that one ̶s̶p̶a̶m̶m̶e̶r̶ member, please don't post about your product in this thread. I'm not interested in that product, and don't want to start another worthless $#it storm thread. Thank you.
To that one ̶s̶p̶a̶m̶m̶e̶r̶ member, please don't post about your product in this thread. I'm not interested in that product, and don't want to start another worthless $#it storm thread. Thank you.
Thread Starter
Super Member
Joined: Nov 2003
Posts: 880
Likes: 4
From: Ponte Vedra Beach FL/ Hampstead, London, England
'84 380 SL/ '02 XK8
Alternative UV protection product: - once both lenses have been polished to restore clarity, they should be sanded with 1500 grit finishing paper, this ensures the clear coat has a ‘key’ to enable adhesion.
When you spray clear coat on the sanded lenses it fills in those light scratches and makes them clear and glossy making them look brand new. SprayMax® (aerosol spray) is a 2K clear paint: two-component acrylic resins plus isocyanates hardener that contains UV protection
Product Application- shake aerosol can vigorously for two minutes before activating. To activate, take the red button from the cap and attach it to the pin on the bottom of the can. Put the top of the aerosol can on stable on a stable surface and push the red button firmly and press the pin into the can. Shake again for two minutes to ensure activator is thoroughly mixed with clear coat.
Apply 2-3 light coats and allow 5-10 minutes between each coat. After the application of the final coat allow approximately 24 hours dry time or use an infra red (IR) drying lamp (recommended)
When you spray clear coat on the sanded lenses it fills in those light scratches and makes them clear and glossy making them look brand new. SprayMax® (aerosol spray) is a 2K clear paint: two-component acrylic resins plus isocyanates hardener that contains UV protection
Product Application- shake aerosol can vigorously for two minutes before activating. To activate, take the red button from the cap and attach it to the pin on the bottom of the can. Put the top of the aerosol can on stable on a stable surface and push the red button firmly and press the pin into the can. Shake again for two minutes to ensure activator is thoroughly mixed with clear coat.
Apply 2-3 light coats and allow 5-10 minutes between each coat. After the application of the final coat allow approximately 24 hours dry time or use an infra red (IR) drying lamp (recommended)
