Is one of your car's sealed headlights starting to show signs of condensation inside the sealed unit? Then it means the headlight housing is no longer sealed properly. To get rid of the condensation inside, you'll have to remove the entire headlight unit from the vehicle and disassemble it. You've now removed the screws and bolts that attach the headlight to your car, but then here comes the tricky part: how to remove the housing from the lens. If you're stuck because of this, don't fret because there are a couple of techniques you can do to successfully separate housing from the lens. Here are some tips:
1. Bake the headlight assembly in the oven.
No, you don't need to channel your inner Martha Stewart. You just need to put the headlight assembly inside your oven at home to heat up and melt the glue that holds the headlight housing and lens together. The idea behind this unconventional technique is simple. Most headlight assemblies today are sealed together with butyl rubber, a synthetic rubber sealant that becomes soft when exposed to heat. To melt the glue without damaging the headlights, put the headlight inside the oven and heat it up at 270 F for about 7 minutes. Once the glue starts to look like black tar, it means the glue is soft enough. Then pry off the housing from the lens with a screwdriver.
2. Use a heat gun.
If you don't have an oven or you just don't like the idea of placing a car part inside an oven, an alternative is to use a heat gun. Start by heating the edge where the lens comes in contact with the headlight housing. Be very careful not to overheat the edge to avoid damaging the headlights. Stop heating the headlight if the glue that seals the housing and lens together starts to look gooey. Once the glue is gooey enough, grab a screwdriver and pry the assembly open until you've completely remove the housing.
3. Other tips to keep in mind
- Before you start heating up the assembly in an oven or with the use of a heat gun, take note of the material your headlights are made of. If they're made of polycarbonate plastic, their melting point is 512 F (267 C) and their heat deflection is at 262.4 F (128 C).
- When heating up a headlight assembly, be very careful not to damage nearby components.
- As you pry open the assembly with a screwdriver, don't force it. Use both your fingers and a screwdriver to carefully open the assembly and remove the headlight housing.
- You can also use a razor to cut open the glue once it's soft enough.
- Another option is to use a hot knife to safely melt the rubber glue and slice it off at the same time.
- If you can't decide which technique to use (oven or heat gun) when removing the headlight housing, choose a method that you're most comfortable and that allows you complete control over the temperature.