UV resistant coating for lights?

[N8N]

Good afternoon,

I am currently working on my 2009 335i putting a new suspension on it. I noticed while putting some parts in the trunk to get them out of the way that the driver's side inner taillight appears to have been hit and chipped. While looking at this I also noticed that the plastic was very crazed when you look closely, as is the pass inner taillight. The outers appear fine although the pass side was replaced 3-4 years ago after a rear ender. While this is obviously a 12 year old car (it was an early 2009 production, made Nov. 2008) I still think that a lens should last longer, especially when a replacement is so expensive.

the turn signal repeaters are also obviously UV damaged, and so is the CHMSL on my Jeep. My question is, is there a UV protectant spray or other treatment I can use on the replacement lens and the other lenses after I polish them up that works well and will keep these shiny and clear?

thanks!

 

[lightfooted]

I also noticed that the plastic was very crazed when you look closely, as is the pass inner taillight. The outers appear fine although the pass side was replaced 3-4 years ago after a rear ender. While this is obviously a 12 year old car... I still think that a lens should last longer, especially when a replacement is so expensive.

the turn signal repeaters are also obviously UV damaged, and so is the CHMSL on my Jeep. My question is, is there a UV protectant spray or other treatment I can use on the replacement lens and the other lenses after I polish them up that works well and will keep these shiny and clear?

Well, you own a BMW...
Cars haven't been "built to last" for a very long time...they've been built to last until the first owner buys a replacement. I have never seen clear plastic last more than a few years before noticeable deterioration sets in. When you say "crazed" I think of the result you get when trying to use CA glue on acrylic...and I think that it's possible there was some similar chemical reaction that happened there. Perhaps road salts or something you drove through that stuck around.

I personally took some sand paper and then polishing compound to my 2001 Passat's OEM headlights and once I had them clear, sprayed on Dupli-Color Acrylic Lacquer multi-purpose clear coat in a few coats and they have been good for 2 years straight. I have replaced them with some custom lights so not relevant anymore. You may get longer lasting protection from a dedicated UV protectant but maybe just repeated coating after a year or so would be sufficient.

 

[-Virgil-]

Cars haven't been "built to last" for a very long time.

That's wrong. Go and learn the actual reality; cars are now lasting longer than ever before...and that's the way the trend has been going for many years.

I have never seen clear plastic last more than a few years before noticeable deterioration sets in.

That can only mean you haven't seen very much clear plastic. Walk through the nearest parking lot or parking garage; most of the cars aren't new, and most of them don't have noticeable deterioration in the taillights and front turn signals.

Come on, now, what valid purpose do you think posting this kind of hyperbolic baloney serve? These kinds of fairytales don't address the OP's question in any helpful or productive way.

 

[-Virgil-]

is there a UV protectant spray or other treatment I can use on the replacement lens and the other lenses after I polish them up that works well and will keep these shiny and clear?

You might study this writeup, or try out this stuff.

 

[N8N]

thanks for the reply. I will have to get a picture of these lenses when I'm home during the day (because I'm in the middle of a suspension job, I haven't been driving it to work)

it's odd, the plastic is not foggy at all like you see on headlights (although my headlights are starting to finally show fogging as well, that was not unexpected) but have very small cracks all over them, looks kind of like a piece of safety glass that's been shattered but not fallen out of its frame if that makes any sense. but from 20 feet away you don't notice it at all.

The other two lights I mentioned don't look like that either just have a foggy/chalky appearance like you'd expect from plastic lenses exposed to the elements. Being cheap, if I am going to invest in UV protectant I will just polish those other lights up and spray them rather than buy new ones.

Edit: Also, any opinions on "ULO" brand replacement lights vs. genuine BMW? Price difference isn't super dramatic, but I'm obviously not even that impressed with the original BMW lights. Also these lights are generally not even lit other than the parking light segment; the actual brake light is the "adaptive brake light"/rear fog light. Going to order from ECS Tuning and those are my options (because I have a credit with them due to having ordered a bunch of suspension parts)

Please don't think I'm trying to go cheap, I've seen some discussion that ULO might actually be the OEM. I've just never heard of them so I'm asking. All the suspension stuff I bought was Koni, BMW, Febi, or Lemfoerder.

 

[lightfooted]

Sounds like stress fractures to me, either from objects hitting them, people leaning on them (or pushing on them) maybe or temperature extremes causing them. The fogging may be easily removable with just dishwashing soap or something similar but the fractures are likely not going to disappear unless you could reflow the plastic.

 

[N8N]

Getting off topic, but I wouldn't trade this car for a newer one. In fact I liked my ex's E46 better (RIP, it was totaled in a rear ender otherwise I probably would have tried to buy it from her when she was done with it.) I find that most new cars are less appealing than the older models.

Sent from my LG-G710 using Tapatalk

 

[-Virgil-]

it's odd, the plastic is not foggy at all like you see on headlights

That's pretty common. The haze seen on headlamp lenses is the (used up) hardcoat on the front face of the lamp, not the plastic itself. That's why you often see hazed/yellowed headlamps with perfectly clear turn signals right next to them, in cases where the turn signal is a separate part from the headlamp (signal lamps aren't usually coated unless they share a common lens with a headlamp).

have very small cracks all over them, looks kind of like a piece of safety glass that's been shattered but not fallen out of its frame if that makes any sense. but from 20 feet away you don't notice it at all.

That's called "crazing", but you already knew that. It can result from chemical attack, thermal shock (or less-abrupt thermal cycling repeatedly over a longer period of time), or impact. It is not a result of someone leaning or pushing on them.

The other two lights I mentioned don't look like that either just have a foggy/chalky appearance like you'd expect from plastic lenses exposed to the elements. Being cheap, if I am going to invest in UV protectant I will just polish those other lights up and spray them rather than buy new ones.

No need to spray them; just polish them with appropriate plastic polish.

Edit: Also, any opinions on "ULO" brand replacement lights vs. genuine BMW?

One is made by ULO and comes in an ULO box.
The other is made by ULO and comes in a BMW box, usually at a higher price.
(that is to say, ULO is the OE supplier for a great deal of BMW lighting)

 

[lightfooted]

I find that using a clear coat on the lens helps fill in the finer scratches made by the polishing compound that may be visible once dried off and washed up with water. I tried both leaving it bare and using the clear coat and the clearcoat appeared clearer once dry.

[Rule 8 violation removed by moderator]

 

[N8N]

No need to spray them; just polish them with appropriate plastic polish.[

I did that a year or two ago, they're already chalky again, hence my comment. Don't have a garage or carport anymore, so everything sits out.

One is made by ULO and comes in an ULO box.
The other is made by ULO and comes in a BMW box, usually at a higher price.
(that is to say, ULO is the OE supplier for a great deal of BMW lighting)

Good to know. Pulled the trigger this morning, with my credit at ECS Tuning, the ULO light was literally half the price of getting the OEM one from getbmwparts/Tischer (who is apparently not doing counter pickup anymore due to COVID, so I'd have to pay for shipping too, but I'm actually rather annoyed at their parent dealership for pulling a fast one on me just to get me to come in to have my car inspected... but that's another story for another time. Executive summary - got a flyer in the mail "Takata airbag recall event" so I took my car in even though the airbag had already been replaced, just in case - well the only open recall on my car had something to do with the HVAC blower but they did a full "courtesy inspection" and wanted me to do about $14K!!! worth of work! I get it, but the middle of a pandemic is not the time to trick people into coming in.)

 

[markr6]

This Meguiars stuff has a good rating. I purchased some after sanding/polishing my 2005 Jeep years ago, but was afraid to try it. Thought maybe it would make things worse? So I just let it sit on the shelf.

https://www.amazon.com/gp/product/B01M4RVVX6/?tag=cpf0b6-20

 

[Buck91]

I've used nothing but regular waxing on my 2011 F150 tail lights an they still look new. Headlights are primarily just frequent waxing though I used to use blue magic headlight protectant as well. They also look new except for some minor chips due to impacts. Truck lives outside 24/7/365. I've used various waxes over the years but most often was meguiars D156 after a wash. Often with some type of paste/liquid sealant applied in spring and fall.

I switched this year to their hybrid ceramic, which I hope to keep as a topper over the liquid ceramic spring and fall...

 

[Magio]

Yeah Ive found frequently waxing the headlights with a good wax is very good a keeping the haze away.

 

[Alaric Darconville]

Yeah Ive found frequently waxing the headlights with a good wax is very good a keeping the haze away.

The singular of "data" is not "anecdote". Even a "good wax" is not going to keep UV and heat from damaging lenses. It might help keep some chemicals away from the protective coating, and may reduce the effect of road grit from abrading that coatnig, but the chemicals problematic to that coating might also be problematic to wax.

 

[Magio]

The singular of "data" is not "anecdote". Even a "good wax" is not going to keep UV and heat from damaging lenses. It might help keep some chemicals away from the protective coating, and may reduce the effect of road grit from abrading that coatnig, but the chemicals problematic to that coating might also be problematic to wax.

What are you trying to say and why the condesending tone? I never claimed this was some scientific test. All I'm saying is that I had 2 sets of headlights that I originally sanded and polished and afterwards they were clouding again in less than 6 months. I didn't have the money for new headlights at the time so I decided to try sanding them again and applying car wax frequently afterwards. I managed to get 2 years out of one set with no noticeable cloudiness returning until I sold the car. The other I got about 3 years out of with no noticeable buildup before I replaced them with new OEM headlights. YMMV but its worth giving it a shot.

 

[-Virgil-]

The hardcoat on headlamps is basically a special-purpose clear coat. I doubt that there's really much UV protection offered by the various car waxes (and "sealants" and "better than wax, waxless shine in a bottle", etc) but I also doubt applying any of them to the headlamps will hurt anything.

 

[pungo]

On my nearly 20 year old vehicle with over 200k miles, the headlights and tail lights plastic lens look great. I've been using a few coats of synthetic paint sealant (ceramic coat for last several years) on them several times a year and using a spray on synthetic sealant after every car wash. YMMV

 

[N8N]

Is there a way I can attach a photo to this post? My Photobucket is full since the conversion to a pay service

yes, the two inner lights are a mess, even the unbroken one and even the driver's side outer, which is at least 8 years old if not original to the car, looks fine. I'm guessing two different manufacturers, or at least two different plastic formulations? This is why I was asking about coatings.

I think I will go ahead and order that two part spray mentioned earlier, but I won't use it until I also polish my headlights, repeaters, and the CHMSL on my Jeep. Then I'll do ALL the lights save for the pass side inner which I guess it's only a matter of time before it gets broken too.

 

[nbp]

Imgur works well for image hosting.

 

[N8N]

Imgur works well for image hosting.

I'll play with it later I guess... most of the other forums I frequent encourage you to upload directly is why I ask (that wasn't always the way, but it became the way after the Photobucket thing happened)

So, now I have another question. Looks like I need to replace the sidemarkers too, I've already polished them once and they're crazing as well. TYC brand OK or insist on genuine BMW? Former is about half the price of the latter, but I don't want to be TOO cheap and compromise quality.

Crazy thing is the bulbs are still original (I can tell because they're the silver ones, not amber colored), but the lenses are going... and yes I do use my signals!