Posted on

How to Open Butyl Sealed Headlights

How to Open Butyl Sealed Headlights

Tools Required

  1. Oven
  2. Heat gun
  3. Wide blade scraper
  4. Thick gloves
  5. Damp towel or grill protector sheet

This procedure works on butyl sealed housings. Permaseal is not covered here.

Opening headlights isn’t an exact science and you can ask the internet, “How long, and what temperature should I bake them at to open them up?” and you will get 10,000 different answers. There is a pretty common range given though which seems to be between 220 for 10-20 minutes up to 270 for 8 minutes.

General Procedure

  1. Set oven to 240F.
  2. Remove bulbs and metal parts from housings
  3. When the oven is ready, lay the towel or sheet on the rack and put the housing on top. Be careful nothing is toughing any of the metal in the oven.
  4. Set 2 timers (I always set a backup) for 10 – 20 minutes.
  5. Get the housings out when done, and push the wide blade scraper into the groove between the lens and housing.
  6. Start prying the lens away from the housing. Work your way around. Don’t try to go too fast. Get it separated a bit, then move a few cm’s away and start prying again. Some people use a screwdriver for this part, but when you mix a narrow, sharp blade with heated, soft plastic, the plastic is going to get damaged.
  7. As you get one end pried away, you’ll notice the butyl strings off like cheese on a pizza slice. Once it starts to cool, it will start to harden again, and really holds on. If that happens, I use a heat gun on the lowest setting to melt it. You could also use a razor blade; I have done both, but I prefer the heat gun because the glue just shrinks back to the channel or lens instead of falling in and possibly sticking to the chrome.
  8. Eventually, you will be able to just pull it apart with your hands.


  • If you get the glue on your lens and it’s plastic, use “Goo Gone” not “Goof-Off” to remove it. The UV coating will come right off with Goof-Off if you press too hard. First try to just heat the lens again and rub it off with a finger or thumb. If that doesn’t work, use only a very light brushing of Goo Gone, there is no need to push down at all, the solvent will do all the work for you.
  • Using a screwdriver can break or deform the channel that the lens fits in; I use a wide-blade paint scraper for all my prying, and .