So, the other weekend I started the first part of a longer term project than my usual ones.
The dreaded fog light refurb!
First up, was removing the fogs. These release from a screw under the ledge of the rear bumper next to the fog light, and two screws from behind. I needed to undo the bottom half of the arch liner to allow enough room to get the fog light out of it's cavern.
As you can see, they didn't look good...
A bit closer up, They look even worse!
The hardest bit of the first half of the job was splitting the units. For this I used a heat gun to warm the original sealant and a couple of wallpaper scrapers to pry the lens away from the housing.
With the lens off, What was inside made me feel sick!
But what is the cause of this? Some of you may ask... Well, Some bell end at 'Automotive lighting' the company who BMW Left in charge of designing the production of this lamp unit decided to make the main housing of the lamp from diecast alloy. Now any of you into engineering, electroplating or metals will know that if you chrome plate a non-magnetic metal (such as this alloy lamp unit) the finish is going to have a terribly short lifespan!
The poor quality alloy oxidises over time, lifting the surface of the chrome plating and leaving bits of Aluminium Oxide and flakes of chrome plating all over!
So next up was getting rid of the flakes of chrome and the aluminium oxide!
I did this using three methods - First of all our fixed polishing machine at work with a wire brush attachment, then an actual wire brush by hand with the housing clamped in a vice, then finally with a wire brush attachment on in a cordless drill.
It took a fair bit of effort to get shut of all the oxidisation, but it got there in the end.
My next task was using a scalpel to remove all the remaining bits of glue/sealant from the lens units. I used some decent thick masking tape on the lenses to avoid scratching whilst handling them.
After a good clean and de-grease, the housings were then ready for painting.
After four coats of direct to metal spray enamel, they were finally looking much cleaner and blacker.
Next up was cleaning all the stuff out of the inside of the lamp lenses. I couldn't quite get them perfect, but did as good a job as I could using fairy liquid and a toothbrush.
Once the paint had dried, I used a silicone rubber based adhesive sealant to bond the lenses back on. I re-applied some masking tape, applied the silicone sealant to the lamp unit, then pressed the two halves solidly back together.
I then used a couple of cable ties wrapped around the units to keep them held firmly.
36 hours later: With the cable ties cut, masking tape off, they came up quite nicely!
Last step for now, was to re-fit them to the carrier brackets and bolt them all together.
Not 100% happy with the finish of them, I'm sure with more time and better prep, I probably could have got the paint finish a wee bit smoother - but they are looking a hell of a lot better than before!
Yes yes, I know, A bunch of you are probably gonna complain that I've painted a lamp reflector gloss black... With a degree in technical entertainment including theatre and studio lighting, I'm fully aware of the drawbacks of using a 'dark glossy colour' on a reflector. I understand that the light output will indeed be diminished by this, However - I never use fog lights and providing the light illuminates when they are turned on, the vehicle will pass it's MOT test.
Hopefully I'll get some pictures this weekend when they are back on the car!
.... Considering the fact that even if you were to purchase brand new sparkling new ones they would deteriorate in a few years, therefore your refurbishment is the best option long term 
