Ultimate Guide to Professional Headlight Restoration

Thoroughly wash the headlights with a high-pH soap to remove road film, followed by an iron remover if the vehicle has been near railways or heavy industrial areas. This prevents metal particles from being dragged across the plastic during sanding, which would cause deep, irreparable gouges.

In Australian summer, panel temperatures can exceed 70°C. Do not attempt restoration if the lens is hot to the touch. Move the vehicle into a shaded, well-ventilated garage and allow the plastic to cool to ambient temperature to prevent the sandpaper from 'gumming' and the compounds from drying instantly.

Apply three layers of masking tape to the paintwork surrounding the headlight. Use the 25mm tape for the tightest gaps and the 50mm tape for a wider safety margin. Professional detailers often pop the bonnet to gain better access to the top edge of the light and protect the engine bay from slurry.

Submerge your 800, 1200, and 2000 grit sandpaper in a bucket of clean water for at least 15-20 minutes. This softens the paper backing, making it more pliable for the curved surfaces of the lens and ensuring consistent grit distribution during the initial heavy cutting phase.

Using the 800-grit paper and your lubricant spray, sand in a horizontal motion. Continue until the 'slurry' coming off the lens turns from yellow (oxidised plastic) to white (healthy plastic). This is the most critical step; if you don't remove all the yellowing here, the final result will be cloudy. Use firm, even pressure.

Wipe the lens clean and switch to 1200-grit paper. Sand in a vertical motion (perpendicular to your first step). By changing direction, you can visually confirm when you have removed all the 800-grit scratches. Once only vertical scratches remain, you are ready to move on.

Return to a horizontal motion with 2000-grit paper. At this stage, the lens should start to look translucent rather than opaque. Ensure the surface remains soaking wet at all times to flush away the plastic particles and prevent heat build-up.

Use a 3000-grit Trizact foam disc or finishing paper. This step removes the fine 'haze' and prepares the surface for the mechanical polishing stage. The lens should look 'frosted' but very smooth to the touch. Spend at least 3 minutes per headlight on this step.

Thoroughly dry the lens with a microfibre towel or compressed air. Inspect for any remaining yellow patches or deep individual scratches. If found, you must drop back down to 1200 grit and repeat. The surface must be a uniform, dull matte finish before proceeding to machine polishing.

Apply 3-4 pea-sized drops of heavy cutting compound to a firm foam or wool polishing pad. Work in a 50cm x 50cm area (the whole lens) using a DA polisher at medium speed (Speed 4 on most machines). Move the polisher slowly and let the abrasives do the work. The lens will suddenly 'pop' into clarity.

Switch to a clean, soft finishing pad and a fine polish. This removes the micro-marring left by the heavy compound and increases the 'optical' clarity of the plastic. This step is essential for high-end European vehicles with complex projector lenses.

Generously spray the lens with a 70% Isopropyl Alcohol solution and wipe with a fresh microfibre. This removes all polishing oils and waxes. This is vital for the next step; any residue will prevent the UV coating from bonding, causing it to flake off within weeks.

Apply the ceramic coating to a suede applicator block. Wipe onto the lens in straight, overlapping lines ensuring 100% coverage. In Australian heat, the 'flash time' will be fast (30-60 seconds). Buff off the residue gently with a clean microfibre until the surface is slick and crystal clear.

The coating requires a minimum of 4 hours to become touch-dry and 24 hours to fully chemically cure. Keep the vehicle out of the rain and do not wash it with chemicals for at least 7 days. This ensures the UV barrier is at maximum strength to fight the Australian sun.