headlights are such a frequently used part of car so it is expected that they will suffer some deterioration with age. we’re not talking about a bulb that needs to be replaced, or a crack in the headlight unit, this is a more subtle deterioration that happens over the years to the headlight lens, which is mainly caused by uv damage. unfortunately, this will have an impact on visibility on the road – particularly for nighttime driving, and it causes your car to look more tired and worn. apart from poor visibility, you could actually fail your nct or mot over this if the tester determined that this could be causing issues with your visibility on the road.
what causes headlight lens deterioration
- uv damage. sunlight can turn the hard plastic into a shade of yellow. headlight lenses come with a clear top coat to help prevent this, but eventually, the coating wears off, and uv rays get to work.
- debris. lets face it, your headlights take a beating while driving – between insects, gravel and other debris, these cause dips and scratches on your headlight and add to the cloudy appearance.
- traffic film. a layer of film, dirt and chemicals form on your headlights over the years of driving. it’s difficult to fully remove this in a normal non-intensive wash.
- water vapour. this is all about bad seals – water can get in via a poorly sealed headlight, causing condensation which can’t be wiped off. the condensation scatters your beam of light, making visibility at night more difficult than it needs to be.
how to tell your headlights have deteriorated take a quick look at your cars headlights and check for these signs:
- they’re not as bright as they used to be
- they’re not as clear as they used to be (do they look a little yellow?)
- they look cloudy even after a wash
- the beam shine has a foggy appearance
how to restore headlights here’s the good news – you don’t need a mechanic for this! this is a
work you can do yourself at home and do it well. pick up a good headlight restoration kit which will contain all the tools you’ll need and follow our guide below. we recommend the holts headlight restoration kit, or the autoglym headlight restoration kit. both of these kits contain sandpaper, buffing tools, polish and sealant and a drill sanding bit. the most important thing here is to ensure the headlights are clean and constantly wet while sanding is taking place.
Read more: 2005 Subaru Legacy Headlight Bulb
what you need to restore headlights
- headlight restoration kit
- masking tape
- car shampoo and sponge
- drying towel or chamois
- drill, for electric sanding (recommended) – you can also do this
work by hand if you have the right sandpaper and a buffing tool)
- chamois leather towel or, for finishing
step 1 wash the headlights with a high quality car shampoo which can adequately remove all dirt. cover the surrounding area with masking tape to protect the paintwork and plastic trim of the headlight.
step 2 ensure the headlight is wet and attach the drill sanding attachment to your drill and begin by using the sandpaper. work in even lines over the surface of the headlight to remove scratches and cloudiness. you have to keep the headlight wet while you’re sanding to prevent the drill sander burning the plastic and causing more damage – very important! continue sanding, working through the different grades of sandpapers, until you have a smooth, consistent and satisfactory finish.
step 3 attach the buffer to the drill (or by hand) and apply a small amount of the polish provided. this will remove any remaining sanding marks and restore a clear finish to the plastic. remember to work in even lines to get the best possible finish.
step 4 spray the headlights with the sealer provided, which will help protect the finish and prevent the headlight from becoming hazy and oxidised in the future. finish by giving the headlight a final buff with a dry chamois. that’s it, you’re done!
stand back and review your work – your headlights should now restored to their former glory, with yellow tints gone and cloudiness dramatically reduced. if you have issues with condensation in your headlights, you need to also seal the edges around the lens using a silicone sealant. while restoring your headlights, you applied polish and sealant to the lens, so deterioration will now not happen as quickly.
preventing future deterioration
- when cleaning your car’s paintwork, don’t use polish on the headlights. polishes with any abrasive content can wear down the clear coat sealant, making them more susceptible to uv, pollution and marks. if you do want to polish the lights, make sure the product you use doesn’t contain any grit, or use a clear coat sealant spray afterwards to restore the protective coating of the lights.
- keep the lights clean. removing the thin layer of dirt and pollution from the lights can prevent discolouring, and it will reduce the effects of uv radiation – use a high quality shampoo to remove traffic film adequately,
- park out of direct sunlight in the summer months to prevent uv rays damaging the headlights. if you’re storing a car for a long period, we’d recommend covering it to stop uv eating away at the protective clear coat of the headlight covers.
so there you have it! restoring your car headlights really is a simple diy
work that you can do yourself and achieve amazing results. share your before and after pics with us!
author: the filter blog team
7 february 2020