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For removing scratches from your clear ipod viewing window/cell phone screen/and come to think of it this applies to the headlights too and any other plastic pieces that need to be smoothed out/remove scratches/prepped for painting/inbetween layer prepping for high gloss applications/clear plastics/resins (acrylics, plexiglass, lexan, lucite, etc.) such as our RX-8's stereo faceplate and headlights/tailights...

First, make a rought determination of how deep the scratch is. Deep scratches ARE removable but require more work an additional materials. I removed a deep scratch from the ipod face (brand new ipod, scratched by watch during screen removal). Lets assume that the scratch you are working on is deep and in additioin I will provide wording that instructs how to manage minor scrapes.

You can perform the higher grit work with a polishing wheel/polishing compounds but it is not precise and with clear plastics/resins it is far to easy to discolor/deform/weaken by heat (also known as 'burn')

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Almost all materials can usually be purchased at an automotive specialty shop (Checker Auto, Auto Zone, Pep Boys, probably online too)

Materials Needed:

-Wet/Dry Sandpaper (as my metals professor told me it is Abrasive Paper!! since there is no sand only Silicon Carbide impregnated in a resin coated sheet)..various grits:
*220, *320, 400, 600, ^800, ^1000, ^1500, *^2000 (*optional and based on project needs; ^recommended for minor scrapes)

-rubbing compound (3m rubbing compound usually found at automotive store) or plastic polish (same thing )

-polishing/rubbing cloth...very fine...very soft...I personally use an ultrafine microfiber cloth that is like a very large piece of eyeglass cleaning cloth, I've found two decent sized ones in a pack for under $3.50 (which makes me think I should cut it up and use it for cleaning goggles since I don't need glasses)

-Meguiars NXT wax liquid or any other modern polymer based liquid wax (OPTIONAL)

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Steps:

1. Begin every project like this by cleaning the item...just use dish soap and a soft cloth, no abrasives yet.

2. Before we begin sanding here is some helpful tips to ensure a proper finish:

Tips/Rules for Sanding:
-sand face of entire surface, not just the scratched area...this creates a smoother finish that is free from depressions.
-it is preferable to wet sand under a light stream of water which is better than simply wetting the surface and the sandpaper.
-When going up in grit number (finer grit) wash surface, preferably with dish soap to make sure the surface is free of lower grit particles.
-When switching from one grit to the other...sand in a different direction (up and down, now left and right)...this way you can easily gauge your progress in removing the lower grit's sand lines. To view these lines while wet simply hold surface at an angle to the light.
-Use room temperature to cold water temps for wet sanding.
-on flat surfaces it is easier to wrap the sandpaper around a smooth wooden or hard plastic block...this gives you more leverage and can give a more uniform surface in the end on flat/square pieces.
-with plastics, BEWARE of the cutting power of sandpaper...you will be amazed how easy it is to sanddown plastics (well I guess for me coming from metals it seems amazing :p)
-Wet sanding will cut less efficiently than dry sanding but produces a better finish and is all but required on 600 grit or higher sanding work.
-If dry sanding...remember to fully dry the surface to sand for the best results.

3. With Medium to deep scratches start with 400 grit paper, wet sandpaper and surface and begin sanding in whatever way feels comfortable. After only 15 seconds or so look at the scratch(es). If they are starting to soften or are even completely gone...keep sanding until they are gone. If no progress was made at all go to step 3a.

3a. Major scratches or plastics/resins that are exceptionally hard will require more time/effort and so starting at a lower grit sandpaper will reduce that time/effort. Jump down to 220, scratch for a few seconds, check, scratch some more, check. When the scratches are gone...IMMEDIATELY clean the surface and move up to 320 grit...different direction until the 220 scratches are gone. Then move back to 400 wet and use until 320 scratches are gone.

4. Work your way up slowly...from 400 to 600 to 800 to 1000 to 1500 and then to 2000 if you choose. Make sure to complete sanding the scratches left at a specific grit before going to a higher number!!!! otherwise you'll have to go back down and resand all over.

5. Now that you have a smooth finish that has a very light matte look...you are almost done ...make sure to wash THOROUGHLY before the next step and wipe dry with a very soft cloth and give it a couple of minutes to let it air dry.

6. Take out the rubbing/polishing cloth and Rubbing Compound. Squirt a bit on the surface and a bit on the cloth. Begin to vigorously rub the compound on the surface as if you are sanding...rub until product completely dissapears or drys out...apply some more and rub some more until there is a PERFECTLY clear surface or Mirror shine, flawless finish on a colored plastic.

7. Lightly dampen the other end of the polishing cloth and wipe off excess rubbing compound from surface...again dry with soft towel and let dry for several minutes.

8. (Optional) Apply a layer of Meguiars NXT wax to really shine things up...let haze...and polish off, then let wax coat harden by letting the surface dry for a couple of hours.

That's It :D

Razz1

Wax? Never wax those surfaces you need to see through. Wax is not good for plastic/plexigass. It soaks into the pours and yellows and makes the surface.

You will never catch a motorcycle rider waxing his windshiels.

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We aren't talking about that old tin of Turtle Wax you have stashed behind a couple of rusty cans of WD-40 in the back of your workbench ole timer :p

depends on what type of wax you use...also 'wax' is a relative term

Polymer based 'wax' like Meguiars NXT line is perfect for this sort of application...goes on creamy so it is easy to apply a very light layer...hazes quickly...and hand buffs out without flaking (unless you let it dry too long :p). I have personally been using meguiars NXT for the 8's headlight covers for over a year and never ones has it clouded/turned yellow/or anything of the sort

Even most modern carnauba waxes would work great as they have been treated to be totally clear and if buffed out correctly will not cloud.

As for soaking into the pours...that is the idea of wax...coat the surface and smooth out and very minor imperfections in the surface to create a silky smooth surface while providing protection from the elements.

And regarding putting 'wax' on a motorcycle windshield? Here is a direct quote from the 'about.com' archives reguarding 'Motorcycle Cleaning and Care'

"I use Megiuars cleaner wax on my headlight and windshield, followed by a coat of "Gold Class" Megiuars. To get bugs off the screen and headlamp, I use "Blue Coral" car wash. The bugs just slide right off, no effort at all and leave the windshield and headlamp pristine after rinsing. Then rewax again just to be sure but it's not neccessary."

newcastle

iTrader: (3)

Great post but FYI fish aquarium stores sell acrylic scrath/buff compounds that work great! I use to have a 100 gallon acrylic salt water aquarium and damn kids would scrath it all the time! It requires elbow grease and hard work but the final results are remarkable. Check it out sometime.

beachdog

Just be very careful if you are going to wet sand a display that is part of your ipod/pda/phone. These devices have zero tolerance for internal moisture.

Prevention is the best option. You can purchase screen protectors at office supply stores. Same material as automotive clearbra just much smaller size.

J2R

Please also, don't make the mistake of using rubbing alcohol on plastic! (Some people don't know this) It burns the plastic and will cause it crack. NOT A GOOD IDEA.

xdj_jdx

Cool DIY im gonna try that this spring TY!

REsuperD

good info! i'm, however, quite scared of sanding and would like to avoid doing it myself if possible. for very light scratches and mostly haze, i resort to meguiar's plastx, but pretty sure this won't work for deep scratches