Urgent help with headlight lens please!

[iovaykind]

So I took them off reading somewhere that I can sand down the inside of the lens to clear them. Well I got the lens off and started sanding them down but it just looks worse and worse. What can I do? Does anyone have an idea as to whether or not I can actually clear the lens? I wanted all the bumps and stuff on the inside to be gone, but now I really just want it to be clear again. Of course, if I can get it to be clear that would be great. Has anyone else tried doing this succesfully? This is driving me nuts!

[95PimpingCamry]

Sand it smooth with progressively higher grits, eventually wet sanding it with 2000 or 3000 grit. Then use McGuire's PlastX and polish it to death.

Take your time, it will require a lot of time and effort. It's better to take your time and do it right, then to rush it and do a crappy job.

[iovaykind]

Should I be doing this with a tool or using my hands and taking my time with strokes back and forth? What grit should I start at. Again, these are all wet sanding grits right?

[DxElite]

If you can use tools, use them carefully, and be careful not to sand any deeper than the lowest you want. Start with 80 dry grit with a electric tool to remove most the plastic and get it almost all even. Then work your way up the dry grit paper using a tool if you want, until you get it very close to all even. Then go to hand sanding with higher grits and get as high as you can find and try to make it as smooth as you can. Then switch to wet sanding with the lowest WET grit and work your way up to the highest wet grit. Finally use the meguars polishing compounds, this you'll have to use a foam polishing wheel. There are different levels available that you can start with like sand paper before you go to the final PlastX, but it depends on how much you're willing to spend. Working from lowest to highest with small jumps will get you better results, and the polishing compounds will clear it up.
I've done this with my clear tail lights when it got scratched, but only gotten to wet sanding then gave up and decided to just cover it up with paint so I don't have any experience with going through the polishing compounds and how clear it'll really be.
Good luck.

[iovaykind]

is it possible to make the plastic clear again? the thing is that..as my dad pointed out.. its hard to use tools since its curved inward, as compared to the outside of the lens which is curved outward and can be polished with rotary tools. i'm planning to spend a day sanding but i want as much info as i can before i begin again since i already messed up once due to lack of research. i had success today with getting some of the bumps and stuff sanded out. The problem is that the headlight lens isn't clear anymore. Should I continue sanding or start again from a low grit and slowly continue to the high grit. And at which point should I feel the inside of the lens and feel that it is actually smooth and not bumpy?

[DxElite]

It is possible to make the plastic clear again, but it'll take a lot of sanding and polishing.
Low grit is just used to remove the material you want to get rid of. So you don't have to start over with the grits, just keep going higher since you've removed the bumps and parts you wanted gone. The use of power tools just helps with fatigue and get things done faster, but shouldn't be relied on with higher grits when its all evened out and you're starting to get it smoother. After you've reached the highest dry sanding you can get it'll start to feel more smooth. Then you'll go to wet sanding that's even higher than dry sanding. And basically the higher you go with wet sanding the smaller the scratches will be and more foggy the plastic will get because the scratches are very small, but will feel even more smooth than dry.
You should stop and feel the plastic for smoothness when it looks like the sand paper isn't removing much anymore at every grit level. It should feel as smooth as the sand paper itself or smoother. And always try to remove the dust while sanding because it'll just get in the way and most of your sanding will just go to sanding the dust instead of the plastic.
When you get it as smooth as you can with wet sanding at the highest grit you can find, its the rubbing and polishing compounds job to make it clear. Polishing/Rubbing compounds is like liquid sand paper but it works on the microscopic level and like sand paper there are different levels of it. Start with Rubbing compound that is a lower grit than polishing to help clear it up some before trying polishing compounds. You can try Meguars PlastX after the rubbing compound and see if it'll clear it up. If it's not getting to what you want, try going with a lower grit polishing compound Meguar makes for body paint and then work up to the PlastX again. It might take a lot of polishing to get it really clear but it can be done.
Good luck.

[islandboy57]

I bought the lens restoration kit from Checker's before - this is for the outside, but it does the same thing. It came with the sandpaper and plastic polish. It helped some, it probably would have been even better if I was more patient but the results were decent. It looks better than most other gen 3 headlights out on the road.

[iovaykind]

From info it seems as though I can use a rotary tool but how can I make it so that I can use it on the inside of the lens that is curved inward? That's really the only problem I see coming out of this project right now..

[KevinACrider]

The only tool I can think of that you'll really be able to use, is a 90* angle grinder with a sanding disc on it.

[DxElite]

Originally Posted by iovaykind

From info it seems as though I can use a rotary tool but how can I make it so that I can use it on the inside of the lens that is curved inward? That's really the only problem I see coming out of this project right now..

Yea, that is a problem with an inward curve it's hard to use any power tools to speed things up. With the rotary tool you'll be limited by the size of it and how much you can do by laying it as flat to the surface as you can while sanding. It'd still be pretty hard to get a smooth/even surface doing that, but if you can figure it out it'd probably speed things up. The only other power tool that I can think might work is a corner palm sander its pretty small so it might fit but it'd still be hard to use it and get an even surface.
But it looks like the best option is by hand with sand paper wrapped around a stiff sponge to help keep the contact even.

[iovaykind]

i'm gonna go with sand paper wrapped about a stiff sponge.. what grits should i purchase? i'm still not completely done with initial sanding down of bumps, keep in mind.

[DxElite]

When you go to your hardware store, you'll see that sand paper is categorized in levels of grit: coarse, medium, fine, extra fine, super fine, very fine. There's also a similar category system for wet sand paper. I recommend one of each category for both dry and wet sand paper.
I know it sounds like a lot, but the idea is to remove the bigger scratches made by low grit paper with higher grit paper in turn making smaller and smaller scratches by going higher in grit and using rubbing and polishing compounds until they're no longer visible to the naked eye.
I recommend starting at 80 grit to remove most of the material, my experience is 80 grit works with both hand and power tool, but 60 grit is really chunky and doesn't work well without a power tool. You may be able to skip one category or every other, but it'd take longer to sand the larger scratches of a lower grit with a higher grit paper. If you want to try and save money you can try skipping one or every other of the "fine" categories where the scratches are very small already. But you do have to do all categories of wet sanding since that is the more important steps before going to compounds.
For the polishing stage, you can try Meguiars Headlight Restoration Kit, this should be able to remove the super fine scratches from wet sanding and give you the clear lens.

[KevinACrider]

Forget the categoris, just get some 80, 200, 400, 800 dry. Then hit it with some 400, 800, 1600, 2000 wet. The numbers are not exact science, just grab a few sheets close to each number. You can also pick up the multi-packs which will contain various grits.

Dx, 80 isn't too bad. I've hand sanded with 32 before. The shit is like a cheese grater but if you hit the body putty with it before it's completely hardened, it works like sex. Gives you a great surface to start the finer sanding with.

[DxElite]

Originally Posted by KevinACrider

Forget the categoris, just get some 80, 200, 400, 800 dry. Then hit it with some 400, 800, 1600, 2000 wet. The numbers are not exact science, just grab a few sheets close to each number. You can also pick up the multi-packs which will contain various grits.

Dx, 80 isn't too bad. I've hand sanded with 32 before. The shit is like a cheese grater but if you hit the body putty with it before it's completely hardened, it works like sex. Gives you a great surface to start the finer sanding with.

I forgot about the variety packs and your grit number suggestion is valid, but we are talking about sanding plastic for the ultimate goal of a clear lense. Jumping too high from grit to grit may leave deep scratches that too high of a grit can't remove without causing pitting from working on an area for too long to remove those deep scratches. And for people who are not experienced at doing this, going at lower gradations limits the chances of mistakes.

[KevinACrider]

Very true. I always overlook the "first timer" factor. Once you're above 150 though the grits are pretty even and smooth for good material removal. Regardless, I agree with you, use more grades and keep the increases closer together.