How to Tell if Glass Scratches Are Repairable (Before You Waste Time or Money)

A practical guide to assessing scratch depth—and knowing when it’s time to call a pro.

Last month, a homeowner here in Austin called us in frustration. They had ordered a scratch removal kit off Amazon to fix their sliding glass door. After hours of polishing—and making the damage worse—they finally gave up. The scratches were now hazy, more noticeable than before, and covered a larger area.

Luckily, Glass Savers was able to restore the panel to like-new condition—so clear it looked untouched. But it would’ve saved time, money, and frustration if they had known from the start that these scratches were too deep to be fixed without professional tools.

This guide will help you avoid the same mistake by teaching you how to quickly assess scratch depth, determine if a DIY attempt is feasible, and know when it’s time to call a pro.

Step 1: Determine the Type of Glass

Before you even evaluate the scratch, identify the type of glass:

  • Tempered? (Most doors, windows, and shower panels are.)

  • Laminated or low-iron?

  • Coated? (Low-E or anti-reflective coatings are often on the interior surface.)

Why it matters: Specialty glass types are more sensitive to heat, pressure, or grinding. If you’re unsure, proceed with caution or consult a pro.

Step 2: Clean and Dry the Area

Use a good glass cleaner and a microfiber towel to remove all dirt and residue. Water spots or smudges can hide the real depth of the scratch.

Pro Tip: Inspect the glass in bright natural light or under a flashlight at a low angle (30–45°) to highlight the scratch more clearly.

Step 3: The Fingernail Test

Gently drag your fingernail across the scratch:

  • No resistance?
    Probably just a surface blemish or mineral deposit—often DIY-polishable.

  • Slight resistance but no catch?
    A medium scratch. You may be able to polish it out by hand with effort and the right product, but results vary.

  • Your nail catches easily?
    That’s a deep scratch. It’ll likely require professional resurfacing with proper tools and techniques. Attempting DIY may cause distortion or haze.

Step 4: Sharpie or Masking Test (Optional Pro Tip)

Mark the scratch with a thin line of Sharpie and wipe with glass cleaner:

  • If ink stays inside the scratch = it’s deeper than it looks.

  • If ink wipes away completely = it’s surface-level.

Step 5: Know the Limits of DIY Kits

Most scratch removal kits sold online are only effective for extremely light surface damage. If:

  • You can clearly see the scratch from 6 feet away

  • Your nail catches it

  • It covers a large area

…then a DIY kit won’t cut it.

Warning: Improper use of abrasives can worsen the damage or permanently distort the glass.

When to Call a Pro

Call a professional if:

  • The scratch is deeper than a fingernail width

  • It covers a large area or involves multiple scratches

  • It’s on tempered, laminated, or low-iron glass

  • The panel is high-end, expensive, or hard to replace

In the Austin job we mentioned earlier, the customer spent hours trying to fix deep scratches with a kit that wasn’t designed for that level of damage. Glass Savers came in and fixed it quickly, but it would’ve been faster and easier to just call from the start—especially if they’d known how to tell what’s DIY-friendly and what’s not.

Still Not Sure?

Take a clear photo of the scratch in good lighting and send it to a glass resurfacing expert. Many professionals can assess it quickly and let you know whether it’s worth attempting on your own.

Final Thoughts

Trying to fix deep glass scratches without the right tools can lead to distortion, haze, or even more damage. But if it’s a light surface blemish, you might just be able to fix it yourself with some patience and care.

Knowing the difference is key to saving time, money—and the glass itself.

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