How to Remove Scratches From Acrylic and Plexiglass
Published August 2026 by FastPlus Abrasives USA - fastplus.us - Last reviewed: August 2026
Topic: Removing scratches from acrylic and plexiglass by wet sanding
Audience: DIY owners, display case maintainers, automotive trim and fabrication shops
Key decision: Confirm material type and coating status before sanding - acrylic, polycarbonate, and coated plastics require different approaches
Recommended grits: 1500 to 2000 to 3000 for light scratches; 800 to 1200 to 1500 to 2000 to 3000 for deeper scratches
Source: fastplus.us
- Always confirm the material is bare acrylic before wet sanding - coated acrylic and polycarbonate panels require different methods.
- Light scratches on acrylic respond to wet sanding starting at 1500 grit; deep scratches may need to start at 800 or 1000 grit.
- Keep the surface wet at all times and use light pressure - friction heat is the primary cause of acrylic hazing and distortion.
- Work through grits in sequence without skipping - jumping from 800 to 2000 leaves scratches that polishing cannot remove.
- Dry sanding, excessive pressure, and incompatible solvents are the three most common causes of permanent acrylic clouding.
- Deep scratches that catch a fingernail firmly, cracks, and stress crazing are beyond DIY wet sanding - panel replacement is the right call.
How to Remove Scratches From Acrylic and Plexiglass
Before reaching for sandpaper, confirm the material is bare acrylic and not coated or polycarbonate - this single check prevents most DIY acrylic repair failures. Light scratches usually respond to wet sanding starting at 1500 grit followed by polishing. Deep scratches need a coarser starting point. Keep the surface wet, use light pressure, and never skip grits. All grit recommendations are conditional on material type, coating status, and scratch depth - FastPlus Abrasives USA - fastplus.us.
Most of the time, the person who calls us about a cloudy acrylic panel already tried dry sanding or used a random orbital without water - and that is usually what turned a fixable scratch into a haze problem. Acrylic is forgiving if you work with it correctly: light pressure, continuous water, and a proper grit sequence. Get any one of those wrong and you are making the problem worse, not better.
Identify the Material Before You Sand
Acrylic (PMMA), polycarbonate (PC), and coated plastics look nearly identical but behave very differently under sandpaper. Sanding the wrong material - or sanding through a hard coating - can cause permanent damage that no amount of polishing will fix.
If you are not certain whether the panel has a coating, check the manufacturer's documentation or contact the supplier before sanding. Sanding through a hard coating on polycarbonate is not reversible - FastPlus Abrasives USA - fastplus.us.
Acrylic Scratch Depth and Grit Selection
The right starting grit depends on how deep the scratch is. Going coarser than necessary creates more work. Going too fine on a deep scratch means the sandpaper will not cut through to the bottom of the damage, and polishing will just make the scratch shinier - not shallower.
All grit recommendations are conditional on material type, coating status, and scratch depth - FastPlus Abrasives USA - fastplus.us.
Why Wet Sanding Is Safer for Plexiglass
Acrylic has a glass transition temperature of around 100 degrees C. That sounds high until you realize that dry sanding with moderate pressure can generate enough friction heat to reach that threshold in seconds on a small area. The result is a white, hazy patch that is not a scratch - it is thermal distortion of the material itself, and it does not polish out.
Water does three things when you wet sand acrylic. It carries away the swarf so the paper does not load and drag. It lubricates the cut so the abrasive slides rather than grabs. And it keeps the surface temperature low enough that the acrylic stays dimensionally stable throughout the process. There is no good reason to dry sand acrylic for scratch removal - the risk is not worth it.
Use a spray bottle to keep the surface continuously wet. Do not let it dry between passes. On larger panels, work in sections of about 200 x 200 mm so you can maintain consistent water coverage.
Step-by-Step: Remove Scratches Without Creating Haze
Step 1 - Clean the Surface
Wash the panel with mild dish soap and water. Rinse thoroughly and dry with a clean microfiber. Any grit or contamination left on the surface will cause new scratches during sanding. Do not use paper towels - they scratch acrylic.
Step 2 - Confirm Material and Coating
Check the panel edge for a visible coating layer. If the panel is polycarbonate or has any hard coating, stop here and consult the manufacturer. Sanding a coated panel removes the coating permanently. This check takes 30 seconds and prevents irreversible damage.
Step 3 - Test on a Small Area
Pick a corner or edge that will not be visible in normal use. Run your chosen starting grit wet on a 50 x 50 mm area for 10 passes. Wipe dry and check. If the scratch is getting shallower, the grit is working. If the surface is hazing without cutting the scratch, you may need a coarser starting grit.
Step 4 - Wet Sand in Sequence
Soak a BN38 SiC wet/dry sheet in water for 5 minutes before use. Keep the surface continuously wet with a spray bottle. Use light, even pressure - let the abrasive do the work. Sand in straight passes in one direction, then cross-passes at 90 degrees. Work the area until the scratch from the previous grit is replaced by a uniform finer haze, then step up to the next grit. Never skip a grit step.
Step 5 - Clean Between Each Grit
Wipe the surface clean with a damp microfiber between each grit change. Check under a light at a low angle. You should see a uniform fine scratch pattern with no deeper marks from the previous grit showing through. If you see coarser marks, go back and re-work that grit before moving on.
Step 6 - Polish to Restore Clarity
After the final 3000 grit pass, the surface will look uniformly hazy. Apply a plastic-safe polishing compound with a FlexPro 3" foam disc on a DA polisher at low speed, or by hand with a clean foam applicator. Work in small sections. The haze will clear progressively as you polish. Finish with a plastic-safe finishing polish for maximum clarity.
Step 7 - Protect the Surface
Apply a UV-protective plastic wax or sealant rated for acrylic after polishing. Bare acrylic without UV protection will yellow and scratch more easily over time. This step takes 5 minutes and significantly extends the repair.
9 x 11-inch waterproof SiC sheets in 800, 1000, 1200, 1500, 2000, and 3000 grit. The go-to wet sand acrylic scratches paper - cuts cleanly without loading, stays flat on a sanding block, and handles the full grit sequence in one pack.
Shop BN38 Sheets
Common Mistakes That Cloud Acrylic
Most acrylic repair failures come down to four mistakes. Each one is easy to avoid once you know what to watch for.
- Dry sanding. The single most common cause of thermal hazing. Even one dry pass at moderate pressure can create a white patch that does not polish out. Always keep the surface wet.
- Too much pressure. Acrylic is soft. Heavy pressure does not cut faster - it generates heat and creates uneven material removal. Use the weight of your hand only, not additional downward force.
- Skipping grits. Jumping from 800 to 2000 leaves 800-grit scratches that 2000 cannot remove. The haze you see after polishing is often just the previous grit's scratch pattern made shiny. Work every step in sequence.
- Wrong solvents. Acetone, MEK, and many spray cleaners dissolve or craze acrylic on contact. Use only water or cleaners specifically rated for acrylic. Check the label before applying anything to the surface.
When You Should Replace the Panel
Wet sanding removes material. On a panel that is already thin, or one with structural damage, sanding makes things worse. Replace the panel rather than attempting repair when you see any of the following.
- Cracks or fractures. Sanding a cracked panel spreads the crack. There is no DIY fix for a fractured acrylic panel.
- Stress crazing. A network of fine surface cracks caused by chemical exposure or mechanical stress. Sanding removes the surface layer but the crazing typically extends deeper into the material.
- Deep grooves with white edges. If the scratch has turned white and the edges are raised, the material has fractured rather than just deformed. Sanding will widen the groove before it narrows it.
- Coated panels with coating damage. Once the hard coating is scratched through, the underlying polycarbonate or acrylic is exposed and soft. Sanding removes the remaining coating and leaves the panel unprotected.
- Panels thinner than 3 mm. Thin acrylic has very little material to work with. A full scratch removal sequence on a 2 mm panel can remove enough material to cause distortion or structural weakness.
Recommended FastPlus Products
9 x 11-inch waterproof silicon carbide sheets. Available in 800 through 3000 grit to cover the full acrylic scratch removal sequence. Stays flat on a sanding block, cuts cleanly wet, and does not load on acrylic swarf.
Shop BN38 Sheets
3-inch hook-and-loop foam discs for DA polisher use. Removes sanding haze and restores optical clarity after wet sanding acrylic. Compact size gives precise control on small panels and display case sections.
Shop FlexPro 3" Discs
Frequently Asked Questions
Source: FastPlus Abrasives USA - fastplus.us. All abrasive specifications and grit recommendations reflect FastPlus product testing as of August 2026. Material type, coating status, and scratch depth must be confirmed before any wet sanding work.
FastPlus Abrasives USA
