[c900]

In the rebuild of my front-end bingled 2.1 sedan, I've now got to to the point where most of the re-assembly is done, and I'm fitting a spare set of headlights salvaged from another slope-front c900.

I found one of the lights (the RHS one) has a broken adjuster. I note that Bill from Saabits lists upgraded adjusters but they're not in stock. What alternatives are there? I could use zip ties tight around the threaded adjuster stud to hold the stud steady so it doesn't flop back and forth.

Also a good inspection appears to show the inside surface of the glass on both lights is pretty dirty so that needs to be addressed.

Is removal of the glass to clean it inside a simple matter of popping off all the retainer clips? Is there a special or specific way to remove and re-fit those clips so there's no risk of breaking the glass or damaging the plastic headlight housings?

I'm aware that the slope-front headlights have a completely different internal design to the earlier flat-front ones as far as the reflector goes. I don't think adjusters are the same either.

Is the rubber seal strip for the headlight class on early and late c900 headlights something generic (given that a lot of 80's and 90's european cars would have all had similar type headlight designs)?

Craig.

 

[c900]

Today I disassembled the smashed LHS headlight - nothing except one of the adjusters and the reflector are salvagable so the rest has gone into the bin. Casing is badly cracked, and two of the three adjusters were ruined.

I took apart the spare LHS headlight to try and clean it up inside and out as I found one of it's adjusters is not staying put. Getting the glass front off was not difficult - just get all the clips off and carefully work the seal free. The seal was pretty badly gunked with years of dirt but I think that'll clean up more or less ok. I found that the genuine seal (p/n 95 56 697) is NLA which isn't really a surprise.

When I went to gently wipe the silvered reflector surface the silvering start to come off! OMG how can that be repaired? I've read about people trying various types of 'silver' paint with mixed results. Is there any purpose-made kind of spray/aerosol coating specifically for headlight reflectors.

These are slope-front lights (with what seem like ABS plastic reflectors) not flat front ones (which have metal reflectors) btw. I don't want to wipe any more of the silvered surface as the rest of the coating will come off! I'm trying to restore the car after it's bingle not make it worse. ;-)

 

[EdT]

The reflectors on the various headlights that Saab used have the same problem, the reflective coating is not very robust.

The only way to possibly clean the reflectors is to use water, maybe hot and with soap. Like running water from a faucet. Any rubbing will take the reflective coating off.

Putting it in a dishwasher is right out. (I tried that.)

In theory, if you can find a place that aluminizes mirrors, such as those used in astronomical refllecting telescopes, and they're willing to aluminize your reflector, you would get an awesomely reflective reflector, that will last basically forever.

This wouldn't be cheap. I was thinking about it for my NG900, but there were enough decent NG900/OG9-3 reflectors still available that I didn't need to do that.

 

[Matt Dupuis]

Yeah, I was reading your first post and screaming (internally) "DON'T WIPE THEM". Too late, it seems. I've made that mistake on my own.

 

[c900]

Given that the slope-front headlights have what seem to be ABS plastic reflectors I don't think that genuine silverplating would work. If it did, something like this would be suitable:

Silverplater 4 Fl oz /120 mL | Caswell Australia

Part Number; SLVRPL26 | Caswell Australia

www.caswellplating.com.au

but I don't think it'll adhere/etch/stick to anything non-ferrous. The early flat-front headlights have metal reflectors.

 

[jvanabra]

There are places that can coat plastic -

Guide to Silver Coating Mirrors vs. Aluminum Mirrors

Learn more about silver coating mirrors vs. aluminum mirrors in determining optical mirror performance from SPC an innovator in the metal plating industry.

www.sharrettsplating.com

problem is pricing. I paid $150ea to clean and chrome old metal reflectors and that was a lot cheaper than a local specialty coating place. Unless you're going to a restoration, it's much cheaper to do a Hella 60mm et al retrofit.

 

[EdT]

There are places that can coat plastic -

Guide to Silver Coating Mirrors vs. Aluminum Mirrors

Learn more about silver coating mirrors vs. aluminum mirrors in determining optical mirror performance from SPC an innovator in the metal plating industry.

www.sharrettsplating.com

problem is pricing. I paid $150ea to clean and chrome old metal reflectors and that was a lot cheaper than a local specialty coating place. Unless you're going to a restoration, it's much cheaper to do a Hella 60mm et al retrofit.

Correct. Aluminizing is a vacuum-deposition process. It could make an apple shiny if you put it in the aluminizing chamber. What is also true is that aluminizing lasts a long time. A headlight reflector doesn't live in the same sort of environment as a Newtonian telescope mirror, but I would figure ten years life. Of course you want to use sensible bulbs and not some 100/130W monsters.

Also, an aluminized surface is very reflective, over 90% if I recall.

See wikipedia....

The main cost is in actually having the physical plant to do the process, rather than the time or materials used to do the aluminizing. So I expect prices to vary. Anyone who is interested should contact their local astronomy group; they should have some contacts for this service.

 

[c900]

The next part of this then is how do you dis-assemble the headlights to get the reflectors out without damaging/breaking all the inter-connecting parts of the adjusters, etc.?

 

[c900]

Double-post oops.

 

[jvanabra]

Disassembly is pretty obvious, but good luck saving all the plastic parts. Most of them will self destruct.

 

[EdT]

The next part of this then is how do you dis-assemble the headlights to get the reflectors out without damaging/breaking all the inter-connecting parts of the adjusters, etc.?

On the NG900/OG9-3 headlights, the adjusters are balls that go into a socket on the reflector. They pull out.

If you have the headlight apart to that extent, clean out any gunk on the inside of the headlight housing. You don't want to have oil and grease vapours depositing themselves on the reflector and lens. And don't use any silicone sealant--it offgasses while curing.

 

[c900]

I have dealt with the broken adjuster when I rebuilt the headlight in question today after cleaning it inside and outside as much as I could before re-assembly.

Two-step process. Zip ties around the external section of the adjuster shaft to prevent it from falling forward and putting the reflector out of alignment, then silicone on the two pieces of the black part so that once that's set it provides two levels of securement.

pic page

pic page

Not pretty but it will hold the adjuster in position.

Craig

 

[Murry101]

This is the part I designed and printed to replace the broken adjuster in the Hella DOT headlights. It might work in the lights you have too.