MVS Contributor WagonLagan went out of his way to painstakingly document a reflector cleaning, including what to do and what not to, photos, results, etc. In the end, he essentially conducted a detailed experiment on cleaning corroded headlight reflectors.
WagonLagan » I’ve narrowed down the issues I’ve been having with my dim headlights to a likelihood of bad reflectors.
I have a couple questions regarding these that I hope someone can answer or at least theorize.
I found one new headlight with a great reflector from a salvage yard (lucky me!). However, there was some water in it, and I’m looking for a way to SAFELY clean the condensation/water marks off the reflector.
Here are his tips:
- It’s surprisingly easy to tell if your headlight is still reflective or not. When I found the good one in the salvage yard, I could look through the clearer parts of the glass and see the reflection. If you can’t do that, it’s likely your headlight reflector is getting pretty yucky.
- Be careful when removing a headlight from a junk car. Water had accumulated in the bottom of the headlight assembly, and because I was careless it splashed up onto the reflector, causing my need to clean/rinse it in the first place.
- I would not feel comfortable using isopropyl alcohol straight on a reflector I intended to use.
- I’d wager that any type of cleanser is likely to damage, or has a strong potential to damage, the headlight reflectors.
- I see no possibility whatsoever to polish the inside reflector. As I understand it, it is vapor-deposited aluminum, not chrome paint, and would therefore simply wipe off or become discolored.
- Any physical attempt at cleaning the reflector is very likely to do more harm than good.
Step #1: Tap water
Sadly, the reflectors are in such poor condition that any remaining residue is difficult if not impossible to see.
Some dirty water accumulated. No degradation noticed to the reflective surface.
In the left corner on this one, you can see I intentionally scratched at the finish to see how fragile it was. It actually took a bit of force to cause that much damage.
If the surface wasn’t already so badly compromised, it’s likely that mineral spots would have been visible afterwards. I noticed them on my new headlight from the salvage yard when I brought it home.
This was from dirty, stagnant rain water though, so maybe distilled water wouldn’t do this?
You can see the mineral spots in the bottom left of the reflector in this picture:
Be careful when removing a headlight from a junk car. Water had accumulated in the bottom of the headlight assembly, and because I was careless it splashed up onto the reflector, causing my need to clean/rinse it in the first place.
Step #2: Isopropyl alcohol 91%
This seemed to either cause minor degradation of the surface coat, or simply cleaned more gunk off that then spread over the rest of the reflectors.
There seemed to be issues from using the alcohol. At the very least, I theorize that the alcohol was slightly damaging to the finish. Regardless, I would not feel comfortable using isopropyl alcohol straight on a reflector I intended to use. This potential damage becomes more noticeable when comparing Step 1 pictures to Step 3.
Step #3: Distilled water
Damage is noticeable when comparing a Step 1 picture to a Step 3 picture:
^ Step 1 ^ | v Step 3 v
As stated earlier, I believe the alcohol may have done some damage to the finish, and this round of distilled water just rinsed the lifted finish away.
I did some other minor testing. With mild pressure using a cotton ball, I could not see any damage to the surface or residue on the cotton ball (This could be because the reflector was already so old and worn, but I tried this on the parts that were still shiny).
With moderate pressure, however, I would start to notice specks on the cotton ball:
Going past moderate pressure runs the risk of severe, irreparable damage. When I applied moderate pressure and scrubbed, or swiped with heavy pressure, this was the general result:
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After trying all this on the old headlamp, I felt confident trying a distilled water and compressed air combination.
Before and after pictures of the new headlamp.
Before:
Obvious mineral spots. Probably wouldn’t have significantly affected the function of the headlamp (especially when compared to my previous one), but I just had to be a little obsessive.
After:
Noticeable reduction in mineral spots, though there is still some staining at the bottom. I decided to let this go and be happy with the improvement I had achieved.
Lastly, I had noticed there was some discoloration, presumably from normal heat/wear, in the ridges that did not seem willing to rinse out at all:
It is clear to me that distilled water would not be enough to restore any kind of shine or clean any discoloration.
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