[krashDH]

As you all know, it seems the BMW headlights take a beating from UV. The 335 I purchased had yellowed, cracked lenses. One of the many projects I currently have going with this car was to restore these while I wait for my VCG and Whitbread oil lines. The only true way to make this work permanently is to apply a 2k clearcoat. The kits out there that want you to just sand and polish, they'll yellow again because essentially you are sanding off what's left of the clear and UV protection. Even the wipe on UV coatings are a temp solution. I want to do things permanently.

I don't have a good detailed photo of them when I got it, and this one doesn't do it justice of how terrible they were. This was just after a wash, but these lenses were very yellow and looked like a topographical map.



Normally when I refinish headlights, I start with about 300 grit and work my way to 1200. These though, I actually had to start with 100 grit. I worked my way up to 1200 with a DA sander. Here's a few shots after I got them all sanded. The one thing to note is you need to sand until the lens is completely uniform. Ie, you either have to sand off ALL the existing clearcoat into the actual plastic, or if yours aren't in bad shape, just sand enough to get an even layer. If you see any "streaks" where the shade changes, it means you haven't gotten even material (ie, combo of clear and parent material):







I built myself a home made paint booth from a 10x10 pop up tent on the deck. I can't do it anywhere inside since my garage is full. Not a plug for these guys, but I've been using Spray Max2k for years with headlights. I used their headlight 2k 2-1 clear for this set. 2k is NASTY so make sure you have the correct PPE. But this stuff for headlights has the UV protectors/inhibitors built in. It's also got a bonding agent that flexes better with polycarbonate vs their standard 2k Glamour which is used for paint clearcoat.

Here's the result after 5 coats. I knew there would be a bit of orange peel so I wanted enough coats to wet sand after to get rid of the peel:







Brought them inside to dry:



Then I hit them with 2k, 4k, and 5k grit to knock off the orange. Need to wait at least 24 hours for the clear to cure before doing this:

[krashDH]

Here is the final result. I think they turned out great. If you're OCD and a stickler like me, you can see the ghost image of the projector where it's kind of "burned" into the inside of the lens. You can only see it at certain angles. There's also some slight microcracking you can see in the sun/at the right angle on the inside, but that's nothing that can be solved except with new lenses.









I have a set of Lamin-X film covers to finish it off once they're mounted back on the car.

I've started tearing into the VCG repair as well. Once that's buttoned up I'll move onto the hot side oil lines and all the other wear items on that side.

[lowrydr310]

They look amazing!

But for that effort I'd rather dive in and replace the lenses. That's no easy task, but in my case I have that 'ghost' burned in inner lens damage and a problem with the adaptive bracked that needs to be addressed, so the lenses must come off.

What's your experience with the longevity of that specific coating? I have two other cars that need some attention, clear lenses but I can't find any coating to last longer than 6 months before they start yellowing again.

[krashDH]

Originally Posted by lowrydr310

They look amazing!

But for that effort I'd rather dive in and replace the lenses. That's no easy task, but in my case I have that 'ghost' burned in inner lens damage and a problem with the adaptive bracked that needs to be addressed, so the lenses must come off.

What's your experience with the longevity of that specific coating? I have two other cars that need some attention, clear lenses but I can't find any coating to last longer than 6 months before they start yellowing again.

I've done plenty of projector retrofits so very familiar with lens replacement as well.

In my experiences, the aftermarket lenses are garbage. They look nice at first, but where these companies cut corners is on the clear. They will chip/crack and start fading quickly. Then you're doing what I just did anyway. If you can get your hands on some OEM replacement lenses, that would be the only way I'd go, if you're comfortable baking headlights and removing lenses.

I've used their 2k for years on headlights. Before they had this specific headlight 2k, I used their 2k "Glamour" meant for body paint clearcoat. I've got a set of lenses on my truck going on 7 years with no protective covers and they still look new. This headlight 2k is superior for poly because of the UV inhibitors built in and the bonding/flexibility it has. But it's still a 2k clear. You need the hardener. 1k clears won't do the job. This with a set of the Lamin-X film and they'll look new a long long time since the film protects from UV as well. I don't anticipate ever having to do it again, it's a one and done if done correctly.

[lowrydr310]

Originally Posted by krashDH

I've done plenty of projector retrofits so very familiar with lens replacement as well.

In my experiences, the aftermarket lenses are garbage. They look nice at first, but where these companies cut corners is on the clear. They will chip/crack and start fading quickly. Then you're doing what I just did anyway. If you can get your hands on some OEM replacement lenses, that would be the only way I'd go, if you're comfortable baking headlights and removing lenses.

I've used their 2k for years on headlights. Before they had this specific headlight 2k, I used their 2k "Glamour" meant for body paint clearcoat. I've got a set of lenses on my truck going on 7 years with no protective covers and they still look new. This headlight 2k is superior for poly because of the UV inhibitors built in and the bonding/flexibility it has. But it's still a 2k clear. You need the hardener. 1k clears won't do the job. This with a set of the Lamin-X film and they'll look new a long long time since the film protects from UV as well. I don't anticipate ever having to do it again, it's a one and done if done correctly.

I'm replacing lenses on my E93 and E90. My E90 lenses are perfectly clear with zero yellowing however they're pitted. My E93 lenses are clear with no pitting but they're slightly yellow and hazy.

Baking is no help on these LCI headlights on my E90 since they're permasealed, but I've experimented on an old busted set and it's doable if you're careful and take your time, and requires cutting the lens off, then cutting the permaseal to remove the remnants of the clear part that's fastened to the channel. E93 would be next but I haven't done enough reading to determine how to get the lenses off or what projectors to upgrade with.

I was planning on adding headlight film to all the new lenses, would that not be sufficient to keep them from yellowing or pitting?

[krashDH]

Originally Posted by lowrydr310

I'm replacing lenses on my E93 and E90. My E90 lenses are perfectly clear with zero yellowing however they're pitted. My E93 lenses are clear with no pitting but they're slightly yellow and hazy.

Baking is no help on these LCI headlights on my E90 since they're permasealed, but I've experimented on an old busted set and it's doable if you're careful and take your time, and requires cutting the lens off, then cutting the permaseal to remove the remnants of the clear part that's fastened to the channel. E93 would be next but I haven't done enough reading to determine how to get the lenses off or what projectors to upgrade with.

I was planning on adding headlight film to all the new lenses, would that not be sufficient to keep them from yellowing or pitting?

Yes, the film on the new lenses will help, absolutely. It only covers the front though so if it starts chipping on the top, it will work it's way to the film and likely stop there.

On one of my retrofits I replaced the poly lenses with glass and the Lamin-X provides a protective barrier for rock chips and such. Can't go wrong with the film for longetvity

[BB_cuda]

Originally Posted by lowrydr310

I'm replacing lenses on my E93 and E90. My E90 lenses are perfectly clear with zero yellowing however they're pitted. My E93 lenses are clear with no pitting but they're slightly yellow and hazy.

Baking is no help on these LCI headlights on my E90 since they're permasealed, but I've experimented on an old busted set and it's doable if you're careful and take your time, and requires cutting the lens off, then cutting the permaseal to remove the remnants of the clear part that's fastened to the channel. E93 would be next but I haven't done enough reading to determine how to get the lenses off or what projectors to upgrade with.

I was planning on adding headlight film to all the new lenses, would that not be sufficient to keep them from yellowing or pitting?

E93 is cake in comparison to E90. A heat gun will get E93 apart along with some prying. As you say, E90 is medieval torture and takes patience. I have a project on the very far back burner that needs to get restarted. I purchased new OE housing lenses from a guy in Prague.