sanded headlight forever, and polished. Still milky appearance.

[pman626]

I test sanded part of my headlight (circled in red in photos) for a long time to see if I could restore transparency to the polycarbonate.

Used 600, 1000, 1500, 2000 grits, then polished with rubbing compound.

No matter how long I sand, I just can't get rid of the milky appearance. especially when looking from an angle, as shown in photo.
You just can't see the chrome with full clarity.

I removed all the severe yellowing, but the milkiness has always remained.

I'm thinking I could sand away half the thickness of the plastic, and it will still look milky.


Have you ever sanded headlights forever, and they never become clear?

This is a 22 year old lexus

 

[KirkH]

I've never polished any that were that old but yes there could be such degradation that the cracks and hazing ("crazing") are too deep.

 

[Eldorado2k]

You shouldn’t expect them to be as clear as your expectations until after the polishing step.

It’s almost like a newborn baby, the thing is gonna be ugly for the 1st 3-6 months no matter what you tell people. Lol.

Heck, they usually don’t come clear until you finally buff off the polishing compound, meaning they still look like crap while you’re in the process of machine polishing them.

 

[pman626]

i don't see any cracks or crazing.
it's just uniformly milky.

i polished a long time with the DA polisher.

the plastic looks smooth and shiny. but milky especially from a side angle or an off angle from the driver door.
If you look straight at the headlight, you can see the inside 75%.
25% cloudy is the best I can get it.
It also has a permanent slight yellow hue that might be baked in.

i think we might have some special kind of UV damage in Socal with the car parked outside 24/7.

 

[Eldorado2k]

Compared to how bad they were, you can’t really expect perfection. Headlights aren’t created equal.

Now that you’ve improved them, if you want to prevent them from going bad again you might want to look into Lamin-X headlight film.

The Light tint they offer would make a good match with your cars paint. Here’s how mine looks.

 

[TTQ B4U]

I test sanded part of my headlight (circled in red in photos) for a long time to see if I could restore transparency to the polycarbonate.

Used 600, 1000, 1500, 2000 grits, then polished with rubbing compound.

No matter how long I sand, I just can't get rid of the milky appearance. especially when looking from an angle, as shown in photo.
You just can't see the chrome with full clarity.

I removed all the severe yellowing, but the milkiness has always remained.

I'm thinking I could sand away half the thickness of the plastic, and it will still look milky.


Have you ever sanded headlights forever, and they never become clear?

This is a 22 year old lexus

Sanding is fine but I wouldn't go much below 1000 grit. Some will go 800 but not me. No need other than to save a tad bit of time. I use a drill and circular sanding pads. Try and stick with 3M Trizact product. There is a difference and it's worth it. 1000-1500-2000 then either spray or use something like Cerakote's Headlight kit. For an OTC product it works pretty well. If your car sits outside it will last about 2 years. Not bad for $20. Their clear is super easy to use/wipe on. I had it on my sons car and only re-did it once in 5yrs.

If you polish them back you'll need to use PPF to keep them from turning again.

In your case, my belief is the hazing is inside through and through. Too much damage has been done to fix that. however, they are better than they were. For me, I'd try and pick up a pair off e-bay or like and simply replace them depending on the condition of the rest of the car and how long you plan to keep it, etc.

 

[FlordPerformance]

auto makers are designing the headlights with LED's and using a small filament/bulb that create heat within the headlight housing. This bulb generate heat to melt snow/ice away form the lights.. without this small heat bulb, snow and ice would stay on your lights. However the catch here is the LED don't like heat and shortens the lifespan. So even though you've clean the outside of housing.. the damage is within the housing cause by these heated bulbs.

 

[TTQ B4U]

auto makers are designing the headlights with LED's and using a small filament/bulb that create heat within the headlight housing.

which specific makes and models?

 

[Eldorado2k]

auto makers are designing the headlights with LED's and using a small filament/bulb that create heat within the headlight housing. This bulb generate heat to melt snow/ice away form the lights.. without this small heat bulb, snow and ice would stay on your lights. However the catch here is the LED don't like heat and shortens the lifespan. So even though you've clean the outside of housing.. the damage is within the housing cause by these heated bulbs.

Mercedes Benz used to make cars with little wipers on the headlights.. Those were the days when cars had Class. Lol.

 

[FlordPerformance]

The only way to verify this is to check for the smaller secondary bulb within the housing. I know our 2020 Connect has this secondary bulb along with the LED.. if you hold your hand on the headlight housing (exterior) you can fell that it's warm even hot at time.. this is to melt away any ice/snow. again shortens the life of the LED.. and we've had to replace the LED's 3 time over the last 4 years.

 

[Eldorado2k]

The only way to verify this is to check for the smaller secondary bulb within the housing. I know our 2020 Connect has this secondary bulb along with the LED.. if you hold your hand on the headlight housing (exterior) you can fell that it's warm even hot at time.. this is to melt away any ice/snow. again shortens the life of the LED.. and we've had to replace the LED's 3 time over the last 4 years.

There’s not enough snow to justify that… Especially in California. What a load of crap. Not saying I don’t believe you, but who the hell thought of such a deceitful idea?

 

[FlordPerformance]

Just like when auto makers claim that the active shutter system on 2018 and new cars is suppose to help with aerodynamics and better fuel economy.

 

[Eldorado2k]

Just like when auto makers claim that the active shutter system on 2018 and new cars is suppose to help with aerodynamics and better fuel economy.

I still can’t get over the fact that modern cars turn off and start everytime you hit the brakes for more than 2 seconds…

 

[Flash Gordon]

I finish sanding using 3,000 fwiw.

Are you using water during any of the steps?
What kind of compound are you using??
What about pads???
What about polisher?!?!?

Enquiring minds want to know