How to SAND glass to remove DEEPER scratches?

[Mike Phillips]

How to SAND glass to remove DEEPER scratches?

I get a lot of questions about car detailing via email. I never mind answering people, but with email, only ONE set of eyeballs see the answers. Yet we all know, if one person has a question, it's highly likely other people have the same question. So, in order to LEVERAGE my typing time, (I'm on the clock so there must be a benefit to the company), I simply answer questions on this forum. PLUS - Google does a GREAT job of analyzing the content on this forum and then ranks it high in the search results. So, helping one person, ends up helping a lot of other people and that's what I'm all about.

Here's a recent email with a car detailing question.


From: Mistry Auto Garage
Sent: Sunday, November 23, 2025 7:12 AM
To: mike@drbeasleys.com
Subject: Glass polishing/Buffing

Hi,

I'm Sandeep ISLANIA from India, my company name is Mistry Auto Glass Buffing. I also doing glass Buffing with glass Buffing compound cerium Oxide and with rayon Buffing disc, it's work well and easy to use and results are very well. But some deep scratches are not gone because of glass buffing compound is not for deep sanding it's only for micro polishing. I work since long have too much experience in this field,

So, I'm Glad to see you in your method, before polishing you sending the glass surface for deep scratch is good, But I can't do that because of the right product in my hand actually I don't know what you use in sanding the glass.

So my questions are,

1: Are the sanding supplies available in open market then tell me the product details and where to buy it from?

2: Or it's your own method and product not for all so it's okay?

You are doing well guys, i appreciate your work


Thanks
Mistry Auto Glass Buffing
From India


Great questions Sandip!

Here's my answers to the best of my ability.

For machine sanding glass, I use the Mirka Abralon sanding discs. In order to break through the outer glaze of glass, you need to start with a minimum of 360 grit, but 180 grit will be much faster. Then work your way out to the highest grit possible, like 3000 or 4000. Then start polishing.

IF you decide to sand glass, keep in mind, you must sand the ENTIRE surface equally, or you’ll create a visual imperfection in the glass. Also – when you sand, you must use a rotary polisher and MOVE the polisher in an orbital manner when sanding.

Me? I ONLY work on glass on classic cars. This is real or normal glass. With new cars, the glass chemistry is changing and it’s not worth it to take on the liability to sand the glass on modern cars. It’s faster and cheaper to simply replace it.


Check out these two articles,

3 Reasons Why to Polish Glass to Remove Scratches Instead of Replace it by Mike Phillips


I show the process to machine sand in this article.

1970 Plymouth Superbird Part 2 - Machine Sanding and Polishing Rare Back Window with NSP GL by Mike Phillips



Here's a video from the 1970 Superbird glass sanding project. We made this after the project, so it's voice-over/b-roll style video.

This is me machine sanding the last known OEM back window for a 1970 Plymouth Superbird.

Best of luck to you.


Mike

 

[Sean]

For machine sanding glass, I use the Mirka Abralon sanding discs. In order to break through the outer glaze of glass, you need to start with a minimum of 360 grit, but 180 grit will be much faster. Then work your way out to the highest grit possible, like 3000 or 4000. Then start polishing.

IF you decide to sand glass, keep in mind, you must sand the ENTIRE surface equally, or you’ll create a visual imperfection in the glass. Also – when you sand, you must use a rotary polisher and MOVE the polisher in an orbital manner when sanding.

Me? I ONLY work on glass on classic cars. This is real or normal glass. With new cars, the glass chemistry is changing and it’s not worth it to take on the liability to sand the glass on modern cars. It’s faster and cheaper to simply replace it.

Mike, sanding glass is different than subsurface glass polishing?

I remember you had us using a rayon pad (subsurface glass polishing) and I believe with a rotary?


Sean

 

[Mike Phillips]

Mike, sanding glass is different than subsurface glass polishing?

I remember you had us using a rayon pad (subsurface glass polishing) and I believe with a rotary?


Sean

Sanding glass can be a part of sub-surface glass polishing.

Sub-surface glass polishing is the term I've given and promote in the car detailing world to distinguish between this type of glass polishing and Topical Glass Polishing. As someone that writes a lot, I need terms with specific meanings or definitions so that when we are collectively talking to one another on online platforms and in the real-world, we can discuss the topic intelligently because we're all on the same page.


Sub-surface glass polishing is removing defects BELOW the surface, and this can be done via machine polishing with the right type of glass polish and rayon pads. For deeper defects, like scratches in the glass, as an option, a person could sand first, followed by polishing. Both would be part of sub-surface glass polishing.

Topical glass polishing, like we did in the class you attended, is limited to removing any type of contamination off the SURFACE of the glass.


Hope the above makes sense?