low beam dome - clear or ?

lee · #1 04-01-2002, 05:40 PM

I've seen photos in lockers, and the '92 now on e-bay, and some have a low beam dome with almost no color (e-bay machine looks kinda white frosted) all the way up to mine which looks dark gray in sunlight. The on-line original brochures I've seen aren't close enough for my old/tired eyes to tell what they should be like.

So my question is: What should they look like? And if it's not dark, any ideas on how would I clean it up?

#2 04-01-2002, 05:53 PM

Yes, Novus 3 part plastic cleaner, available from JC Whitney and other places.
GT

lee · #3 04-01-2002, 06:30 PM

sorry if I didn't make myself clear. I've cleaned up the outside (which was old & yellowed). I'm asking about the glass (?) dome over the 9006 halogen bulb inside the housing.

mohrds · #4 04-01-2002, 07:34 PM

I have researched this phenomenon and it appears that the lens deteriorates over time. I have disassembled the headlights in an attempt to find a way to reproduce the outside lens in glass, but ran across the low beam lens issue.

When I disassembled them, I found that the low beam lens (referred to as "The Blob") were full of spider web style cracks and the outer lip was completely broken away from the metal ring that holds it in.

They were not clear anymore. The tiny cracks were filled with dirt and grime causing the blobs to appear grey.

I have decided that the only way to repair them is to replace them. Since you cannot purchase the blobs individually, you will need to replace the entire headlamp assembly.

Sorry for the bad news. You can check out pictures of the guts of the headlights in my locker.

Doug

Beav · #5 04-01-2002, 07:44 PM

Doug, do you think that the 'blobs' could be repaired with the Novus windshield epoxy? I'm thinking, from your description, that the edges catch a bit of hell and break away - do they break so far as to not be stable in the mount? If not, I'm thinking that maybe laying down a thin layer of the Novus filler on the back of the lens would fill in the 'spider webs'. Thoughts?

Beav

#6 04-01-2002, 07:49 PM

I'm sorry but did someone just say "windshield epoxy?" Please tell me that there's some kind of product that you can just spread over your windshield & scrape off and it will fill up all the little chips and divots.....

-A

Beav · #7 04-01-2002, 07:55 PM

It's not meant for that type of application, but I was thinking on a small surface such as the lens it might work, plus it wouldn't be exposed to the elements as it would on a windshield.

The true purpose of it is to repair stars and cracks in a windshield. You might check with your insurance agent, many states have a $0 deductible on glass/windshields. In Colorado I used to get a new windshield in every car come springtime, due to the 'sand' (gravel) they use on the roads there.

Beav

lee · #8 04-01-2002, 08:06 PM

I'm assuming before one could try the Novus epoxy the lens would have to be cleaned somehow, yes? Ideas?

Is the blob a simple cover or is it a lens of some sort - by that I'm asking what the light pattern would be without the blob.

I can't help but think the gray appearance is cutting back on the light output. My old eyes can use all the help they can get at night.

mohrds · #9 04-02-2002, 05:53 AM

The blobs are real glass and it is a focused lens. The image changes as you rotate the lens.

BTW: The headlights I disassembled no longer have the alignment marks on the blob. They had broken away so I don't know which end is up (nothing unusual for me

)

I do not think the blobs can be polished. The cracks run pretty deep.

I was going to buy a new pair of headlights, disassemble them and set the blobs in a bed of hi temp silicone so they do not shatter the edges. Perhaps that will prevent the spider webbing as well.

I have a friend that is a photographer, when he gets back into town, I'm going to have him take pictures of the spider webbing so you can see what I'm talking about. When I try to photograph it, I end up with a white glare...

Doug

kuoh · #10 04-02-2002, 07:00 AM

How did you come to that conclusion? I also took apart one salvaged from a friend's accident, and the blob did not appear to be anything other than a simple convex lense. The image is upside down simply because of the focal point of the lense. The only way the image could be changed by rotating the lense would be if the focal axis was not perpendicular to the base of the lense. This did not appear to be the case from the one I examined.

But back to the original question, there is the possibility that the glass filler could make things worse. It might be fine on a windshield, but the lense is subject to much more heat and the filler material might discolor or widen the cracks since the lense would be subject to much faster and more intense heating/cooling cycles.

KuoH

Quote:

Originally posted by mohrds
The blobs are real glass and it is a focused lens. The image changes as you rotate the lens.

mohrds · #11 04-02-2002, 08:37 AM

When I removed and cleaned the blob, I held it up to a six panel window and rotated it around. The panels in my window appeared to get narrower & taller and if i turned it another 90 degrees, they appeared wider & shorter.

It's not extremely scientific, but it was enough for me to know not to mess with it.

There is also a notch in the projector case that I assumed fit a key molded into the lens, but there was not enough of the lens left to determine that.

If you know of a place I can order blobs from inexpensivly, I'll experiment to find a suitible replacement. So far the only thing I've come up with is the trying to gut a Hella Optilux Model 1100 Projector Fog Lamp that has a 40mm lens.
http://www.spmotorsports.com/hella.html

For $50 it may not be a bad thing to experiment with, but I don't know if that 40mm is the diameter or the focal length.

I'd be foolish to think that it would be an exact match, but stranger things have happened.

Doug

kuoh · #12 04-02-2002, 07:43 PM

I think that perhaps you were not able to maintain the same distance or axis while turning the lense, which accounted for the change in appearance.

As for the measurement, 40mm is probably the focal length. It translates to approximately 1.5 inches, and I know the lense diameter is more than that.

KuoH

Beav · #13 04-02-2002, 08:05 PM

Quote:

Originally posted by kuoh
I think that perhaps you were not able to maintain the same distance or axis while turning the lense, which accounted for the change in appearance.

KuoH

Either that or the 'eyeball' has astigmatism.

Beav

Ron Mummert · #14 04-02-2002, 09:02 PM

Why do I yearn for the days of the simple five buck sealed beam headlight?
Worked for me!

Ron.

Beav · #15 04-02-2002, 09:13 PM

It's this kind of stuff that writes my check Ron. Some new cars now use multiplexed wiring for all devices. When your headlamp burns out the first tool you'll grab won't be a screwdriver, it will be a computer scanner. Ridiculous, huh?

Beav