Everything you need to know regarding headlights



Headlights on modern day vehicles are made from a type of thermoplastic polymer called polycarbonate, as opposed to older vehicles where they were made from glass. Polycarbonate has huge advantages over glass in that it is easily moulded into complex shapes, is very impact resistant and very transparent to visible light, better then many types of glass. The disadvantages of this type of material is that it is not very suitable for long term UV exposure and can discolour, yellow and begin to crack. Given the extreme strength of UVA and UVB rays in North QLD, bad headlights are a common sight and will take away the overall look of a vehicle, but more importantly will lower the amount of light your headlights transmit onto the road leading to dangerous night time driving.

From factory polycarbonate headlights have a thin top layer of a UV resistance coating. This coating does a fantastic job of protecting the polycarbonate from discolouration for years. However in extreme climates (nearest the equator) or for older vehicles, eventually this layer breaks down and the headlights will go that all to common yellow colour. Depending on the angle of the headlight (the more horizontal it is, the more UV it will get), how much time it spends outside, the quality of the polycarbonate used by the manufacturer and many other variables effect the overall speed this happens.


We like to differentiate headlight damage into three different categories. Stage 1 damage is when the headlights first go this yellow colour, it is usually when the UV resistant coating is still on the headlight however has broken down. At stage 1 the damage is quite easy to fix and people use all sorts of products such as toothpaste, metal polish, automotive paint polish etc. to remove the yellowing damaged coating. The results can sometimes be nearly perfect and these people will then always comment on how awesome it worked and anything else is a waste of money (trust us, we hear this all the time). With this damaged layer now removed, for the first time in their life the headlights are unprotected. To go from new to stage 1 may have taken years or perhaps even a decade to happen, however now the process is sped up and the headlights can start to deteriorate in a matter of months. The other thing that starts effecting the headlights more now is abrasion from driving and the UV penetrating through the entire headlight (remember the barrier that was once there from factory has been removed) and effecting the polycarbonate deeper and also the shiny silver reflector of the headlights. 20140729_104950

An example of what we would refer to as stage I UV damage


We now enter what we refer to as stage II damage. This damage can still be polished out with some success, but the headlights will no longer look completely new since the damage is now deeper (put them side by side next to a new car and there will be a difference). Some people are still happy with the results and move on with life, where as others are now no longer happy since their headlights don’t look perfect. This might lead them to try something a bit more abrasive, or they will simply do the headlights more often. In direct sunlight the headlights may have some scratches or even light cracking. This is from the UV now penetrating all the way through the polycarbonate and destroying it from the inside. There may also be cracking or flaking of the silver reflector lenses inside the headlights.IMG_3383

An example of what we would refer to as stage II UV damage


We now enter what we would refer to as stage III damage. The headlights have most likely been polished a number of times throughout their life and every time the damage comes back worse and worse. The results get worse and worse and eventually the abrasive being used does absolutely nothing. This is because the damage is nearly all the way through the headlights, has multiple scratches and hairline cracks and simply trying to buff off 0.5 microns of polycarbonate does nothing. Eventually the cracks can get that bad that they can’t be removed and the silver reflector inside the headlight gets completely destroyed from peeling.

VW headlight

An example of what we would refer to as stage III UV damage


To completely prevent the damage from starting, always put a little bit of wax or sealant onto the headlights when you do your paintwork (you are doing your paintwork right?!). If this is done from when the car is new, the OEM coating on the polycarbonate will never breakdown as a sacrificial layer of wax or sealant is being put on top to protect the headlight from UV.


There are now plenty of proper restoration kits available off the shelf. The main thing you want to look for is a kit that comes with some sandpaper, some polish and the most important thing is a UV protective coating. Since your OEM coating has already broken down, you want to replace it after you do the process. A restoration kit without a coating is really not solving the issue for you if you are after a proper solution.


Our process has been tweaked over a 10 year period as technology has advanced and our understanding of this complex process has been learnt. This has led to the best possible results money can buy in headlight restorations and in most instances is completely different to what others offer (usually just a quick hit with a rotary buffer, a sheepskin pad and some polish).  So lets go through our process with this Nissan 350Z with stage II damage.


Stage 1 and stage 2 – after taping up the surrounds of the headlight, careful wetsanding is performed with two different grits of sandpaper (depending on severity of damage).


Stage 3 – machine compounding is performed to remove sanding marks and to restore clarity.IMG_3643

Stage 4 – machine jewelling is performed to increase clarity even more.


Stage 5 – Cleansing the headlight and creating a complete clean surface for the quartz coating to bond to.


Stage 6 – Application of quartz coating.


Stage 7 – Application of protective layer to ensure quartz coating cures properly.


And the results. Perfect clarity up close even in direct sunlight.


This process takes much, MUCH longer (on average 1 hour per headlight) then what most other companies do, uses much more product (the products used tally up to around $200 for the full bottles, not including machines and pads being used) and requires much more skill and expertise. This results in a slightly higher cost to the customer then what some other companies charge (some places actually charge the same as us anyway so go figure) but the results are guaranteed to be the best you can get and the headlights are properly protected. With correct maintenance (just like we mentioned with new headlights, applying a bit of wax or sealant every now and then) the results can last forever.