Safe & Effective Headlight Lens Removal ????

[jaudette3]

I have a number of Cibie Biode headlights that I need to remove the lenses from and it's critical to not break any as the lenses are very difficult. Over way too many years I have dried heat (baking in the oven), many solvents, and of course razor blades and the like. I break about 1/4 of them and that is just not acceptable.

Has anyone found a way to do this? I have no idea what solvent Cibie used but after 50-60 years it gets rock hard. I will be forever grateful if you can help.

Many thanks,
John

[CheckBookChuck]

I have recently successfully removed the lens from 4 early 1970’s Cibie headlights.

I placed the headlights face down on the bench and filled the reflector cavity with Acetone to above the level of the joint at the lens and the reflector. Then I added Acetone around the outside of the lens at the joint. I let it set overnight and was able to pry the lens off with very little effort.

WORK VERY SLOWLY on the prying step.

I had a 100% success rate and was able to reassemble all 4 lights.

Good luck,

Chuck

[jaudette3]

Thank you Chuck. Do you have to worry about the acetone damaging the reflectors? Many of these are NOS units that I simply have to install amber shrouds into.

JA

[alberta]

Hi, I have soaked door side mirrors in acetone over night. This released the glued in mirror and no harm to the mirrors. The only problem is the acetone really stinks and you need a well ventilated work space.

John

[jaudette3]

I'm going to have to get some Acetone. This is what I learned about adhesives vs. solvents from Claude (my favorite AI Bot):

Epoxy resins:
Acetone
Methyl ethyl ketone (MEK)
Toluene
Xylene
Dichloromethane (methylene chloride)

Polyurethane adhesives:
Acetone
Methyl ethyl ketone (MEK)
Toluene
Xylene
N-methyl-2-pyrrolidone (NMP)

Acrylic adhesives:
Acetone
Methyl ethyl ketone (MEK)
Ethyl acetate
Toluene
Xylene

Butyl rubber adhesives:
Heptane
Hexane
Toluene
Mineral spirits
Naphtha

Acetone Alternative:
Methyl ethyl ketone (MEK) is often considered the closest alternative to acetone in terms of its solvent properties. It can dissolve a wide range of resins, plastics, and adhesives, making it a highly effective substitute for acetone in many applications.

Acetone appears to be the all-around champ backing up the experiences reported here. I'm going to try it first on an assembly that is going to have the reflectors restored and I'll let you know.

Claude didn't know what adhesive was most commonly used by auto manufacturers in France in the 1960s'. I suppose that's getting pretty esoteric - fun stumping an AI Bot though. j

And this from the Gemini, the Google AI Bot:

There isn't definitive information on the exact adhesive used in all French cars during the 1960s, but some possibilities include:

Butyl Rubber:
This was a common adhesive used in car manufacturing for various purposes throughout the 20th century, including potentially headlight lenses.

Silicones:
Early silicone adhesives were developed in the 1950s and became increasingly used in car manufacturing in the following decades.

Epoxy:
While less common than the other options, epoxy adhesives were available in the 1960s and could have been used in some headlight assemblies.

It's also possible that different manufacturers used different adhesives depending on the specific model and year.

JA

[doigthom]

Don't use MEK. Will take the skin off your hands. I worked as a paint Technician for Allied Chemical. Nasty stuff.

[CheckBookChuck]

No issues whatsoever.

Used to use MEK until it was banned in California.

Good �� soaking!