DIY: Baking your headlights! Put on your Chef hat and lets get cooking!
If you are interested into modifying your headlights for a retrofit, adding leds, painting the chrome, removing the amber, or just resealing the lights to keep out moisture this guide is for you. There are many different ways to do this but this has been the my technique for my Forester.
If you are working on a 06-08 Forester, I have another guide to help you uninstall those lights here. Otherwise look online for a guide to remove your headlights from the car and lets get into the kitchen!
Tools
These are a few tools to make your life and job easier: A flat headed screwdriver, a set of Knipex Pliers, multiple styles of clamps,micro fiber towels, Morimoto rubber butyl, oven mitts or heavy duty work gloves, and an oven or a Heat gun.
How to
Having your headlights removed, you will allow the oven to reach 250F. On the 06-08 Forester it has a metal bracket on it, you can either remove it or use it to prop the headlight up in the oven. The bracket will get very hot, take care when handling it if you leave the bracket on.
Then find a proper pan for the headlight, this gives you a way to transport the light and keep it upright in the oven. Make sure not to face the headlight down as the lens could easily burn/melt at this temp. Another area to take care of you need to keep the wires free of resting on metal, burned headlight wiring will make a fun project into a nightmare.
Set an oven timer for seven minutes and don’t walk off to far and forget about it. Too much time in the oven can cause the plastic to melt, lens to haze over and many other issues could arise. When your timer goes off make sure to have proper hand ware, the headlight will be quite warm to the touch. You can use oven mitts or heavy duty work gloves to keep the heat off your hands.
If you aren’t keen on plopping your headlights into the oven. You can also take a decent heat gun and run it along the seam warming up the butyl and headlight seam. After a few laps around the headlight seam you put your screwdriver into the a clip and see if you can get any movement between the two side. Once it begins the move keep going and if you run out of heat just warm them back up again. Make sure to take care and use proper hand protection as your headlights will get warm quick.
Now we will speedily work all the way around the headlight to release all the plastic clips. If you take to long it will allow the butyl to cool and it will become tougher to release. If this happens use your heat guy or pop it back into the oven to reheat the butyl. Using your flat head screwdriver to do this and you can gently pry the seam apart. After you have released all the plastic tabs/clips you will start to use your hands to pull the two pieces apart.
Keep your eyes on the rubber butyl sealant as it is a bear to remove from any surface especially the headlight lens. Now with both sides separated you can start your project!
If your project was to just remove and reseal the lights you can use the heat gun or the oven to reheat the sealant with it warm you can now remove it. I find using a flat head screwdriver a great tool, just slide it through the channel while wiping off the excess on to a paper towel. After you have cleaned the old rubber butyl from the headlight, you can start with a fresh roll of butyl all the way around the headlight housing seam. Cut off the excess and press it firmly into the seam channel.
With all your upgrades sorted out and the new butyl in place and begin to reseal the lights. Put the lens and housing together and while lining up the tabs. Placing the headlight back into the oven or start heating it with your heat gun. For the oven you can leave them in for a little less time(five minutes) given the butyl is exposed and should warm and loosen up much quicker.
Put your hand protection back on and remove it from the oven. You will start to use pressure to make the two pieces one again. As the seam gets tighter with butyl fills in the area use the pliers or screwdriver to pull it further together. Again we will work around the entire headlight and back to the where we started, even consistent pressure will make a proper seal. Make sure that all the plastic clips are in their place and holding the lens and housing properly.
Lastly you can put your microfiber cloth over the lens and use clamps to finalize the sealing process. Leaving the clamps on while the headlight and sealant cool down, once it is cool to the touch you are ready to install them again.
Picking up the headlight you can now check your work, looking for a solid line of sealant around the whole light. Double checking your clips are in place. At any time that you feel the butyl has started solidify before the headlight is sealed, take the headlight back to oven or the heat gun and warm it up. This will allow you to continue work and finishing up your task.
Congratulations you have completed your task! Enjoy your newly refreshed lights and lets hope water ingress won’t be an issue. This isn’t a tough task but it is a bit tedious and no one likes doing the same project twice..