Cleaning Headlights with Alcohol

Last night I discovered something unexpected. I wiped the yellowing headlights on my 2002 Honda Odyssey with Isopropyl Alcohol (91%) and the yellowing has almost disappeared. No hard rubbing, just rubbing back and forth a few times with a wet paper towel. I thought it might be only temporary because of it being wet, but it looked just as good today. Not like brand new, but definitely much less yellowing. Has anyone used this before or seen it used? This was almost completely unexpected to me. Isopropyl Alcohol is not a strong detergent and there definitely not any abrasives.

I’m guessing (hoping I’m wrong, though) that you’ve merely cleaned the dirt out of the miniature cracks–the cracks are still there, and still distorting the beam pattern. AFAIK, the only ways to de-haze plastic is to abrade the crazed layer, or utilize a strong solvent that will “melt” the crazed layer away. I do not think isopropanol is a strong enough solvent for that! (Acetone much more likely.)

I’m inclined to agree with meanjoe, but I thank you for the tip. It’s well worth trying.
Personally, I clean them with regular polishing compound applied using a variable speed drill with a wet sponge buffer pad. It works beautifully. I suspect that any fine abrasive suspended in a viscous media would work well. I’ve even heard of people using toothpaste.

I think I agree. I avoid the problem by using Plastix polish when I wax the cars and I’ve never had a yellowing problem. I did post a year or so ago about a guy that had cleaned his up by sandpaper and some solvent but can’t recall what the solvent was. I think once it yellows though, its got to be polished back which would include sanding and polishing.

That solvent may have been - Deep Woods Off. There was a post a while ago about using Off to clear the headlights. Well, I tried it and it did help clear the lenses. Not like new, just a moderate improvement. It appeared to actually melt the surface of the lens a bit.

There was discussion about whether it would last. Well, it is 4 months later and it did last but still it is not a replacement for new lenses.

Why mention this? I think the carrier for the deet off contain is isopropyl alcohol although Off doesn’t list this on the bottle.

There is a new product to polish lenses now from Duplicolor containing a spray polish and a clear coat to fill in and seal the surface. That is an additional step the others don’t do. I’m going to try it.

Every time that I see cars with cloudy headlight lenses, I have to wonder…
Why has this never happened to any of my cars, or to the cars of any of my friends and neighbors–even after 10+ years?

While I garage my cars, that cannot be said of most of my friends and neighbors, so there must be a difference other than protecting cars from the sun at least part of the time. And, the makes and models of the non-affected cars is fairly diverse, including…Toyota, Subaru, Ford, Hyundai, Lexus, Lincoln, and Acura.

Does anyone have any theories as to why some people’s cars never seem to suffer from this affliction?

I had read on another post here, to use Lacquer thinner to “melt” the crazed layer away.

Works great, but just a quick wipe or as the layer melts it will get sticky and you will leave lint behind.


i seen it on tv! headlight wipes! wipe on/wipe off. just like new. it must work.

I was told to use toothpaste…

I don’t know the exact numbers, but I presume you could buy a whole quart of lacquer thinner for the price of the wipes.
I also forgot to mention in that post that, giving the lens a good buffing afterward helps too.

As far as the TV ads go, I always wonder how many people are gullible enough to bite at these ads.
I’m not saying that some good things don’t start out as a late night TV ad, but I’m always a little skeptical.


Sylvania makes a kit with a UV protector as the last step. It was rated as the best kit last year. Lots of cars in Ga seem to yellow. The worst seems to be Mercedes with the round flat headlights.

turtlewax has a simple $10 kit that has 3 small scuff pads and polish. it got good reviews for price and effectiveness. my kid has about $500 of various cleaning equipment for his cars. buffers, waxes, polishers, clay bars, literally tons of stuff. i know he has several electric buffers with an assortment of pads. i might try to use them with some polishing compound.

The lights on my Mustang tend to last about 5 years before they get really bad. I’ve always just replaced them as I can get replacement lens assembles for around $50 a side.

“The worst seems to be Mercedes with the round flat headlights”

That has been my observation also.

In any event, doesn’t anyone have any theories as to why I and my friends, neighbors, and relatives have never had this problem with the headlights on our Toyotas, Subarus, Hyundais, Fords, Lincolns, Lexuses, and Lincolns?

Maybe alcohol with a little lacquer thinner mixed in is worth trying.

Up until recently, I haven’t experienced this issue on any of my cars. However, since I have started using my '03 Camry as a regular commuter to work, it has rapidly developed fogged lenses. I think it’s a combination of; material, aging, environmental exposure and design.

The car in question spent the first 10 years of it’s life on rural highways. It’s now being driven on the expressway and therefore subjected to a daily sandblasting of debris at 80mph. The lenses have also aged and are more likely more brittle than when they were newer.

I think it was lacquer thinner but the price stunned me the last time I bought it. Upward to $30 a gallon. Tooth paste is just a mild abrasive and polish.

Re: deet. I have some 100% DEET (and nothing but) from years ago I bought at REI for wilderness backpacking. That stuff will melt just about any plastic it comes into contact with. Small leak absolutely destroyed a compact flashlight and some other stuff in the ditty bag including blowing a hole through the nylon bag…

I think TT is right about the reason. I’m sure there must be a variety of different polymers and molding processes used.

Up until recently, I haven’t experienced this issue on any of my cars. However, since I have started using my '03 Camry as a regular commuter to work, it has rapidly developed fogged lenses.

I wonder if it’s fine particulates in the air that stream past the lens as the car is driven.
If the lights are on and the lens is warm that might increase the abrasive affect.