Old Cibie 5.75" headlight Q

Just a quick Q-- one I think I already know the answer to, but here goes...

I salvaged a pair of Cibie 5.75" hi/lo headlamps out of a 70's Audi (long abandoned in the woods behind my property; incredibly the lights were the *only* remaining components unmolested by vandals and/or entropy!). One in perfect condition, the other appears to have cataracts of the reflector; a cloudiness that can't be wiped away. Is it somehow worth recovering or just FUBAR?

Thanks!

-Eric.
Homer, AK

RedShift42 said:

One in perfect condition, the other appears to have cataracts of the reflector; a cloudiness that can't be wiped away. Is it somehow worth recovering or just FUBAR?

Click to expand...

It's probably more like macular degeneration or retinopathy if it's the reflector. Probably something got through the (vapor-deposited) aluminum's protective coating (some sort of siloxane monomer) and allowed the aluminum to start corroding. Or, if the reflector itself is metal instead of glass, it started oxidizing on the non-optical side and finally broke through to the reflective coating.

Someone might have also tried to fix the lamp using silicon sealant and it outgassed, damaging the coating.

If it were something that could be wiped away, wiping it might actually cause damage to the siloxane. It's better to wash the headlamps with distilled water and a weak dilution of Simple Green so you don't introduce finger oils or drag something across the coating.

If you're lucky, it's still just a surface thing and doing the Simple Green wash will remove the cloudiness without damaging anything. (The washing process is not too difficult-- just use distilled water and rinse, rinse, rinse once it's all clean (always distilled water) until the water sheets off the reflector. If it beads up, that means there's still some kind of oil on the reflector. Dry it in an oven that you warmed to about 200F and then switched off before putting the lamps in, with lenses down.

(I took your color/size/font formatting out; please don't use it unless it's absolutely necessary)

Thanks-- very, very useful. I knew my analogy was off since cataracts is a lens issue, but I lacked the knowledge/vocab/initiative to use macular degeneration, etc.
I'll check back in a few days w/ the results.
If nothing else, that single unit will make a natty headlamp on an old Yamaha brat-rod motorcycle project of mine.

W/ regards to the formatting, somehow everything got goofy when I pasted the question's text in from a failed private message to one of the senior members here-- seems PM's were down late last night. I wish there was just a Format-Restore button.

-Eric.

Interesting backwoods find, but it is unlikely that the one headlamp is in perfect condition. By the time we can look at a headlamp and notice an imperfect reflector, it's far past gone. Reflectors can look really nice and be optically useless, and once they have had years of elemental exposure, they are pretty much guaranteed to have a significant level of optical deterioration. A helpful analogy/comparison is to chrome on the bumper of a restored show car. The best, most expensive show chrome -- the kind that looks about 30 feet deep -- is in fact about 65% to 70% reflective. A new headlamp reflector, on the other hand, is over 95% reflective. Both items look the same to us because of the limits of our eyes, but it's a fairly common topic of disappointed discussion in vintage car restoration forums that "Hey, I had my headlight reflectors rechromed and I still can't see!". There are processes for restoring headlamp reflectors, but chrome isn't a part of them.

The Cibie 5.75" lamps are still available new, so it's probably not worth going through the effort/expense to have these restored.

More good info. I hadn't realized how critical reflector perfection is to headlighting.
After a thorough clean up, close inspection at the 'perfect' lamp reveals some pitting forming on the reflector at the bottom lens seam and general mild contamination throughout. Additionally, the lens' vintage tells of life on Alaska's unpaved roads back in the day.
That pretty much assures it's donation to the project cycle rather than automotive use. Given our climate, we're only riding during the long-daylight months anyway, so I've got no problem sacrificing some performance for patina. Should be a great period-correct look.

Of course all this now has me wondering about the viability of that Oscar, long stored in a box in my parents' damp basement. Found it as a kid at a flea market for $5 new. Been meaning have them send it up for years, now I'm not so sure. Darn.

-edit-
Cool, just discovered the Remove Format button.

The time it takes those reflectors to degrade sure does vary. At one time I had a set of 5.75" Cibie lights in a 1958 Cadillac. After a few years, one pair had lost virtually all of the silvering on one pair of reflectors, but the others still looked like new. If I remember correctly, the H4 lights had the "brown" reflectors and the H1 high beams were still good. I think I still have them around, hoping to maybe someday mate them to good reflectors that have damaged lenses.