Headlight reflectors

[getsmart]

Gidday all,

(Garry M - maybe I  should have put this one in electrical?)

One of my headlight reflectors was in poor condition. The silver had almost disappeard with spots of rust.

Knowing that aluminium is used these days rather than silver (even in astronomy in reflector telescopes) I decided to try a little experiment.

On the bad reflector I covered it in aluminium tape, a very cheap and easy fix and tested them side be side.

Below are the results.

1st pic is high beam, Left is silver, right is aluminium tape
2nd pic is low beam, Left is silver, right is aluminium tape
3rd pic is aluminium tape reflector
4th pic is silver reflector

The beam from the aluminium tape is a little more focused/round whilst the silver headlight is a bit more scattered. This confused me a little, more tests required here I think to determine why the difference. But all in all though the silver is only marginally brighter than the foil. Note that these are H4 LEDs. My finding is that if one wanted an easy fix for headlight reflectors the aluminium tape is an excellent replacement when using H4 leds.

My options are  to use the aluminium tape, re-silver or go the aluminium vacuum method which all aren't cheap and I have to send my reflectors away which I don't like to do. Additionally the fog lamp and parker reflectors all need re-doing too.

Rgds, Joe

[lreppond]

The aluminum tape seems to do a rather good job based on the illumination of your garage door.  Your 1964 model is quickly approaching 60 years old and it’s reasonable that the silvering has finally given out.  If you drive often at night, I’d bit the bullet for resilvering or buy new.   However, if you seldom drive at night time, the aluminum foil seems perfectly acceptable. 

[rwmastel]

Maybe others can add some pics of lights on garage doors for comparison.  Remember, the beam shape should be controlled by the lens, not the reflector.  Scattered side to side would cover more road surface.

[getsmart]

Maybe others can add some pics of lights on garage doors for comparison.  Remember, the beam shape should be controlled by the lens, not the reflector.  Scattered side to side would cover more road surface.
Posted by: lreppond
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The aluminum tape seems to do a rather good job based on the illumination of your garage door.  Your 1964 model is quickly approaching 60 years old and it’s reasonable that the silvering has finally given out.  If you drive often at night, I’d bit the bullet for resilvering or buy new.   However, if you seldom drive at night time, the aluminum foil seems perfectly acceptable
posted by rwmastel.

Thanks guys....the beam shape was confusing to me as I had identical bulbs in each so definitely need to check that again. To re-silver there's not just one reflector but 3, that is the main, the fog lamp and parker, all de-graded in my case. This becomes an expensive exercise to have professionally restored. Also more difficult to re-silver DIY as silver requires copper/brass/nickel - happy to hear peoples thoughts on how to re-silver at home. I'd rather spend my limited funds on other parts of the car but also half the fun for me is coming up with solutions myself rather than spill out the cash. But I digress .... what I'll probably do is leave one in the aluminium tape and the other in silver and do a real test when I get the car on the road. Don't forget the H4 leds are many times more bright than the original globes.

Silver has a reflectivity of 94% whilst alumimium has 91%, its not a lot of difference and even with the cheap aluminium tape its still probably north of 85%.

I think its an excellent solution for the budget concious or the DIYers here...

Have attached a chart for comparison

I think the H4 leds have a wavelength of around 500nm but I'd have to double check that to be sure (I'm pretty sure they have a blue light content)

[mdsalemi]

There is more than one spray product known to be pretty darn good. One of them is called "Killer Chrome"

https://alsacorp.com/product/killer-chrome/

This is another that has been around for a long time. As the process is more involved, it isn't much of a DIY process but if you call the manufacturer I'm sure they can put you in touch with vendors offering the service:

https://www.cosmichrome.com

[stickandrudderman]

I've never heard of that cosmi-chrome product and it looks very interesting.
Anyone here got direct experience of it?

[getsmart]

guys n gals....

Chrome is a poor reflector (at least compared to silver, aluminium and gold  ) and I'd guess that the spray on chrome is no better. Just to digress a little, I have a spare set of bumpers that I'll try the spray on chrome products on but haven't decide which one yet. They need the same preparation as anything you're going to spray and most of them need to be applied over 2k high gloss black. Great product though it seems, I've studied quite a few videos and keen to give it a go...

Cheers, Joe

PS. Here is another reflectance table showing chromium vs Silver and Aluminium - I was going to use gold but don't have any lying around at the moment