How to remove yellow stain from plastic?

[JOgden 1,003]

I have a piece of plastic that sat in front of lights, that plastic is now yellowed from the light. Is there any way I can turn this back into white?

Thanks in advance.

[PRESSURE PACKED 14]

Put The Plastic In Front Of The Light Until The Entire Piece Is Yellow...TIME TO BUY A NEW PIECE OF PLASTIC

[Beth n Rod 1,279]

I agree with Rod...it sounds molecular. Think about how glue from artwork you created as a kid yellowed and cracked over time....I think that the light has done this, along with heat and time, and I think it's just seen better days.....

Beth

[Grime Dawg 14]

This is assuming that the color goes all the way through the plastic.

Take some 1500 grit wet/dry sandpaper and cut it into squares (about 1/4 sheet each is good). Put them in a bucket of warm water and let them sit for a good 1/2 hour to an hour. You want them soft.

Sand the plastic with light pressure. Keep the paper wet. You should be able to tell very quickly whether the yellowing is being removed. If it is, keep going.

Once done with the sandpaper, you can use some rubbing or polishing compound (the kind for car finishes) to polish it up and remove the light sandpaper scratches.

They do make plastic cleaner kits but they are fairly expensive and this will usually do the trick.

[RyanH 14]

UV light is killer on plastic. Free radicals are formed from exposure over time and change the chemical composition of the plastic...in a nutshell, the plastic has cancer. Todd's suggestion of sanding makes the most sense aside from trashing and replacing it.

PS--UV is emitted do some degree with almost all lights, except perhaps infrared (heating lamps).

[Beth n Rod 1,279]

Well golly gee dang nabit!! Ryan!!! there you go all technical n stuff again with that jargun. Who wants to free radicals anywho? they'd just ruin the goverment anyways. darn republicans ....(incoherant mumbling)

Rod!~

ps, the plastic is toast.

[PA Dutchman 14]

any chance its nicotine?

[Grime Dawg 14]

As Rod says the plastic could be 'toast'. Or maybe not.

When I bought my truck a couple months back the front headlight lenses were so yellow that I don't think 35% of the light penetrated the lenses.

I had already decided that I would need to replace them. And 'factory' parts aint cheap. I've heard of some of the aftermarket automotive lighting products/lenses catching on fire, so wouldn't use them.

While looking through a local throw away ad paper I saw an ad for a company called "ClearBeemz".

They said they could 'renew' your headlight lenses for just $69.99 (starting at $69.99 that is).

So I hop on over to Google and did a little homework. Came across this site:

Janvil Plastic Polish, Cleaner & Restorer

Read through it and finally bought the product. Which primarily consists of two seperate fine abrasive polishes and a plastic shine product.

Got it, did what it said. Headlights are now Crystal Clear. I was shocked. Really, they look brand new.

But basically I learned you could do the same thing (though not as good) with the 1500 grit wet/dry (which they recommended for really bad areas) and some good automotive polishing compound.

For headlights, I would definately buy their kit.

Here's a couple interesting links on their site. Check out the business link. It may give you some ideas for an 'add-on service'.

Plastic Headlight Restoration, Repair and Renewal. Janvil Headlight Restore Cleaner & Polish will turn back the clock on yellow hazy cloudy lenses.

Janvil: Your Partner In The Scratch Removal, Polishing & Restoration Business.

[Grime Dawg 14]

OK, I guess I should have stated above that the information is just that. INFORMATION for anyone who may need it now or in the future. Worthless ramblings?

If the plastic in question is a small piece of plexi, it would be cheaper and a whole lot less hassle to just replace it.

[RyanH 14]

Still points to the issue that it is mostly a surface defect and can be remedied by getting down to the undisturbed medium. Good post...my jeep's headlamps look like crap. I may check this stuff out.

[Grime Dawg 14]

Go with the small 2oz. kit Ryan. I bought the larger one thinking I might 'offer it' as a service and I've got enough to probably do 15 more cars.

I left my lenses on. As I was working on the truck a neighbor lady came by and asked what I was doing. I told her I was polishing my lenses with this new product I had bought.

She said, "does it work"?

I backed up so she could see that one side was done and one side wasn't and said "You tell me"?

She said, are you kidding me, that is fantastic.

I think you'll find the same thing. It does take a little patience and elbow grease, but it's easy to do.

[gregative 18]

There's a guy that comes to the truck yard where I work and refinishes the headlights. Turns them from yellow back to white. Don't know the product but there is a market for refinishing plastic. If it's cheap plastic it probably won't work but headlight plastic seems to be a heavier grade. If it's cheap replace otherwise might be worth checking out.

[MMI Enterprises 289]

For headlights, telescope mirrors, optics of all sorts, or even your various hard stone surfaces just make a polishing lap...

Melt enough tree pitch in a soup can for to be able to pour about a 1/2" coating onto the surface of a suitable sized saucer or disk to be used as a tool for the object to be cleaned and polished.

Jelly jar lid should work fine as a tool for headlights as example. Use masking tape around edge to contain the pour. Don't boil it and don't expose to flame or you'll have to put out a fire.

As it sets up take a razor blade and cut waffle or crosshatch pattern V's into the pitch every inch or so. This allows polish to move about, for debri to clear, and also prevents suction in use and allows for the next step of pressing the tool into a matching shape of what your to polish. So before total setup of the warm pitch, take the tool and coat it with thin mixture of polish (cerium oxide or ferrous ixide, or rouge and water). Press onto surface to be polished for it to take shape of object to be polished and let it setup until cool and hard as it will get. Takes a few minutes to take same shape.

Now goto town in hand polishing back and forth,turn, then repeat in a consistant pattern keeping surface wet with water and polish until object is once again like new.