Rick @ Layson's........thanks...
Dan, although the Z beams in my Duster have lost a lot of the silvering on the reflectors, they're still superior anything else out there.
If there's visible degradation of the reflectors, they're long past dead. Optical degradation of the reflector is grossly advanced well before you can see it with the naked eye; by the time it's progressed far enough to be described as "just a little imperfect" the lamp is dead. Remember, even the most costly, beautiful show chrome is only 67% reflective, not nearly enough for optical purposes. An as-new headlamp reflector is over 99% reflective.
I know they've been out of prodution for a long enough time now that the supply has dried up to the point that they seem to be made of unobtainium these days.
If the lenses aren't pitted all to hell, you can have the reflectors refurbished. Or you can buy a set of the current-production Cibie 7" round H4 lamps, which aren't Z-beams but are still the best ones easily available (there's a better one made by Koito for Toyota, but it's costly and difficult to get).
I've searched around on the web looking for resilvering techniques or info on separating the lens from the reflector, and found little worth recording.
Well, here y'go:
The first step is to isolate the reflector from all other components. Remove all non-steel parts such as bulb seats and non-reflector components such as bulb shields, etc. The bulb seat is held to the reflector by crimping which can be carefully undone with a small screwdriver after you make scratch marks on the seat and the reflector for later alignment. The bulb shield is sandwiched between the lens and the reflector, so you'll be removing it after you separate the lens from the reflector.
Disassembly of bonded lens-reflector units requires caution. Make a scratch mark on the back of the reflector at the top of the lens so you can identify where the top of the lens goes when you later reassemble the lamps. Place the lamps in a 250°F oven for 30 minutes, then working quickly and carefully with a sharp knife, cut away as much of the white adhesive sealant as you can. Then use a butter knife, screwdriver, and/or other appropriate blunt but narrow edged tool to pry the lens free from the reflector, working progressively around the edge of the reflector to lift it out of the softened adhesive. Work carefully to avoid peeling off the brown base coat from the reflector. It may take several trips back into the oven...when the adhesive cools, it will begin to re-harden. The object is to avoid placing much local stress on the lens, so when it stops moving easily,
stop work and put the lens-reflector back into the oven to warm back up. You'll want to remove all the residual adhesive sealant from the reflector and the lens.
Once it's isolated, put the reflector and lens into the dishwasher (bottom rack) and run it with ordinary dishwashing powder (Cascade, Electrosol, etc.) through a normal cycle. This will usually remove most all of the shiny stuff; occasionally some careful wiping or a second run-through is necessary.
Take a close look at the base coat; if it's in perfect shape, not scratched or peeled or blistered, then you're all set; send the reflector to Martin or one of his teammates at
Vacu-Coat. Tell him it's an optical reflector, in need of aluminizing and high-heat protective overcoat. If the base coat is at all imperfect, contact him in advance, tell him you have a stamped-steel parabolic headlight reflector with damaged factory base coat, and ask for his recommendation for sending the reflector in (does he want the remains of the basecoat stripped, can he strip it, etc.). Most base coats can be stripped from steel reflectors with lye the easiest and safest form is Easy-Off spray oven cleaner. The original type, not the "fume free". Check the label to make sure it contains lye (Sodium Hydroxide). Wear rubber gloves, give yourself plenty of ventilation, apply the lye in a sink, let it stand for an hour or so, then rinse with hot water. Scrub gently with a plastic "Scotch Brite" pad; repeat if necessary.
If the reflector has rust that has roughened its surface, it is not a feasible candidate for cost-effective refurbishment.
If Vacu-Coat for whatever reason can't put on a new base coat (this is highly unlikely), then the reflector must be copper plated and polished to a high shine. Then, nickel plated and polished to a high shine. Then, send the reflectors to UVIRA in Oregon for aluminum vaporcoating and silica glass overcoat. About 9 years ago, I paid $85 for UVIRA's reflectorisation service on a pair of reflectors about the same size as
yours; the price might have changed.
UVIRA
310 Pleasant Valley Rd
Merlin, OR 97532
tel 541-474-5050
The plating shop is probably going to ask you why you're having the first two steps of a chrome plating job (copper, nickel) done but not the chrome. Chrome is *never* an acceptable reflector material; see above.
Once you've got the refurbished reflector back, Reinstall the bulb seat, crimping as required for a secure fit. Make certain to install the bulb seat in its correct rotative position relative to the reflector (refer to your earlier scratch mark).
Do not use any kind of silicone to attach the lens to the reflector. Use windshield urethane, obtainable from an auto glass service center. It comes in various grades; the thin grade is the easiest but also the messiest to work with. Apply a thin, even bead around the inner lip/rim where the lens and reflector meet. Press the lens -- make sure it's rightside up! -- evenly into the bead of sealant, then apply another bead round the outside of the lens/reflector junction. Smooth/press this outer bead into place with a craft stick or finger (messy either way!) and allow time for the urethane to cure completely.
Install new (thoughtfully-selected) bulbs, reinstall the headlamps, aim them on low beam according to the 'VOL' instructions
here, and you're all set.