How To Remove Scratches From A Windshield?

How To Remove Scratches From A Windshield?

Learn about the causes of windshield scratches, windscreen scratch removal materials, and equipment & details of glass window restoration including tips on how to remove scratches from a Windshield. Let’s begin!

 

Causes of windshield scratches

A car windshield scratch can affect a driver’s visibility creating risky and unsafe conditions. The number one reason for scratches on windshields and other windows on a car is wind damage or wear and tear due to wind and dust particles as they pass over the entire body of your vehicle.

remove fine scratches from windshield

Don’t be alarmed. This will happen if you drive slow or fast, in the Amazon, on the highway, within a lazy town, or in the desert. It simply cannot be avoided. Heck! it will also happen if your vehicle is mostly parked out in the open without a protective cover.

 

So there! Now you know why it’s the number one reason. It’s just a matter of time before your entire vehicle including its glass windows, quarter glass (if it’s there!), backglass and most often the front windscreen starts appearing hazy and dull.

 

Reason number two is manual wear and tear caused by regular cleaning and washing. 

 

But I use clean microfiber washcloths, shampoos, and glass cleaning spray!!

Don’t worry! I hear from you! That’s what most people do. Sorry to burst your bubble but improper cleaning and washing practices also (very slowly perhaps…. but surely!) wear away that nice shine on your car and its glass windows too.

 

Let’s move on to reason number three. This one is related to the usually long vertical scratches that appear on the side windows. Your automobile’s side windows are protected and sealed from both sides to prevent water from leaking inside the door.

 

This water may damage the window winding mechanism. The strip on the outside is called the Car Side Window Trim Moulding or the Rubber Weatherstrip. The strip on the inside which is lined with a microfiber material is called  Car Window Rubber Seal Trim.

 

Dust and in particular the grit that gets deposited and sticks to the rubber sealing trims on your car windows often gets overlooked when it comes time to cleaning. Over time repeated rolling of the windows results in fine streaks or vertical scratches on the side windows.

 

remove windshield wiper scratches

Now let’s finally look at the fourth and final reason, which usually results in the deepest most prominent scratch(es) on glass, short of a crack that runs through and through. Deep scratches or pits on the surface of the glass is the outcome of an impact.

 

Surface pitting or chipping may be the result of an impact from road debris, perhaps from a small stone hitting and ricocheting off your glass. Other reasons may include vandalism or even accidental scratches by metal rings worn by someone cleaning the Autoglass.

 

However, the most common reason for such surface damage is a defective or broken wiper mechanism, moving across the glass. A degraded wiper or heavy grit sticking on the edge of the wiper blade can also cause scratches, but these are not as deep.

 

Not cleaning wiper blades regularly or accidentally running a wiper blade dry will also result in scratches of moderate depth. Scratches brought upon by wiper blades are marked in their appearance because they appear in a wide curve on the front windshield as well as the rear windscreen.

 

How can I be sure my car’s rear or front windshield needs restoration?

The ability to look at the road clearly under all driving conditions makes driving much safer for everyone. The first sign of a damaged and the scratched windshield is the dispersion or spreading of light as it passes through.

 

A general dulling or water spots can be seen during the day also but it is only clear once the situation is really bad. Nighttime dispersion or spreading of lights is usually the more pronounced symptom of glass requiring restoration.

 

Other than these, prominent or deep scratches and chips are clearly visible to the naked eye. Short of glass requiring full-scale restoration, you may also be alerted by the presence of swirl marks on the surface of the glass if you were to look at it from an angle.

remove deep scratches from windshield

How to classify damages on auto glass surfaces?

The type of damage can be classified by viewing the windscreen from inside the vehicle or viewing it from an angle in the sunlight.

 

Water spots appear as white colored blotches on the surface. They may vary in size from tiny dots to dime-sized circles.

 

Very light surface scratches appear as swirl marks on the surface or short lines that cannot be felt with a fingernail but seen by the eye.

 

Fine scratches are prominent by the distinct short, random, and slightly opaque lines during the day. Surface scratches typically cause light dispersion especially from inside the vehicle at night. Lightly scratched vehicle glass may also feel rough when a finger is rubbed over them from outside, but your fingernail will not get caught in them. 

 

Deep scratches and surface chips are distinct because they are clearly visible to the naked eye under all light conditions. They can also easily be felt by rubbing a hand over them and they will definitely snag your fingernail. They are usually the most difficult to fix without compromising the safety or optical properties of the auto glass.

 

Deep scratches should be fixed as soon as possible. They put auto glass at a high risk of cracking or breaking due to stress and pressure. If left unattended, deep scratches usually worsen over time, eventually cracking or even shattering the glass.

 

What does glass look like under a high power microscope?

cerium oxide windshield

 

Your car’s glass is specially designed. It is clear (near perfect) and can take a lot of wear and tear as well as temperature variations. Above all, it is designed to be safe. Front windshields and side windows are usually laminated so that they are shatterproof.

 

Rear windscreens if not laminated are almost always made from tempered glass. Despite the fact that your auto glass is smooth to the touch and optically perfect, the story is quite different if you look at it under a high power microscope.

 

The image you see here shows exactly that. Glass surface is actually made up of peaks and valleys. They cannot be avoided in the manufacturing process. The price of your vehicle would really be much much higher if they were to be fitted with such glass.

 

The smaller or fewer the peaks and valleys the better the optical performance of the glass. Chips and pits introduce distortion while hard water spots, scratches, swirls lines, and fine lines reduce the optical clarity and structural strength of the glass.

 

These can turn out to be a serious safety issue for you and your fellow passengers. There are several materials and methods which you can use to protect, repair, and restore the surface finish of your car’s glass.

 

Read on to learn more about how to repair and remove swirl marks, fine or deep scratches, from car windows including rear glass and windshield.

 

Auto Glass techniques that How to Remove Scratches from a Windshield

Auto Glass scratch removing and repair techniques
What tools and materials are required for the repair and restoration of scratched auto glass including windshields?

 

Windshield Scratch Removal Equipment:
  • Rotary power tool:
    • 90o Angle Grinder / Hand Drill / Dual Action Polisher – RPM Range 800 to 3000 
  • Abrasive Pads:
    • Glass Grinding (180 grid), Pre-Polishing (500/1000 grid) & Felt Polishing Pads
  • Backing Plate / Pad (with soft interface pad)
  • M14 Universal Drill Adapter
  • Water Spray Bottle
 
Auto glass restoration materials:
  • Glass Cleaner Solution
  • Glass Cleaning Clay
  • Auto glass repair / Scratch removal kit or Rubbing Compound with Cerium Oxide
  • Fluorine/Ceramic Glass Coating
  • Microfiber Cloth
  • Handheld felt block for corners
  • Vehicle Protection Material for windshield scratch removal:
  • Temperature Sensor
  • Polyethylene Sheet
  • Duct Tape

 

Personal Protection for glass repair:
  • N95 Face Mask / Industrial respirator
  • Safety Goggle
  • Polychloroprene Gloves
  • Critical Issues:
  • 2 inches clearance from the edge of the glass
  • Move grinder at 1 inch per sec
  • Never stop moving
  • Start in the center of damage

Dealing with water spots, fine scratches, swirl marks on a car windshield, rear windscreen, and side glass

 

Front Mirror Scratches

Let’s first discuss how to remove fine scratches from windshields as well as removing swirl marks and water spots or mineral deposits that can appear on any type of auto glass as a result of wear and tear. Such distortions on the surface of the glass are not very deep and can barely be felt by hand.

 

They are however visible to the naked eye when seen from an angle or under certain light conditions. Marks that you may be able to see from about 4 feet may also be considered in the same category.

 

These types of light scratches, general dulling, random wear lines, and swirl marks can be removed by anyone choosing to clean their cars themselves. If that’s you then in fact, there is more good news. I will tell you about some very easily available solutions that you can use to heal fine scratches on auto glass.

 

One such solution is using an acrylic-based clear nail polish or nail hardener. Yes… Nail Polish! Some car detailing experts also recommend using a specially formulated acrylic-based compound for removing scratches. But clear nail polish can and has been used successfully.

 

An important fact, however, is to note that acrylic works better only at healing light scratches or small swirl marks. The clear acrylic-based material will flow into and fill in the grooves to make light scratches “invisible”. You have to let it cure and dry out completely which can take up to an hour depending on the environment.

 

Solve windscreen Scratches

Alternatively, you could help it cure faster using a UV lamp. Again it is very important to mention that you need proper eye protection when working UV lamps. Excess material on the surface of the glass can be wiped off using a very clean and dry piece of lint-free cloth dipped in nail polish remover or isopropyl alcohol.

 

Remember that this method can only be used for a very shallow scratch if you do not have cerium oxide-based buffing material. Cerium oxide windshield scratch remover is a special chemical that combines excellent physical as well as chemical properties.

 

It is not only the perfect abrasive material, it chemically bonds with the glass to fill gaps and form a distortion-free seal. This chemical bonding property of cerium oxide with silicon present in glass prevents the scratch from growing worse.

 

Since the cerium-oxygen-glass compound is softer than glass (it is per se elastic) and can bond the edges of the scratch together. This is why cerium oxide helps in preventing the formation of cracks which may lead to breaking the windshield.

 

If you are going to use a cerium oxide-based rubbing compound make sure to read and understand the instructions and precautions provided with the product. If you are going to use cerium oxide, make sure that you have a dust mask and a pair of rubber gloves.

 

Cerium Oxide is a pretty harsh abrasive. At the very least you need to wear gloves, an N95 face mask, and also cover the rest of your vehicle. It is also recommended that you wear safety goggles, an industrial respirator mask, and an apron over your work clothes.

 

Many people ask, can toothpaste remove scratches from windshields? The short answer is yes. You can improve your auto glass with something as common as white toothpaste. But we will come to that later.

 

First let’s look at a 4 step professional approach, preferred by DIY automotive enthusiasts and recommended by car care and detailing experts.

 
STEP 1 – CLEAN AUTO GLASS BEFORE WORKING ON IT
CLEAN AUTO GLASS

This is a critical step. Why? Because thorough cleaning will allow you to actually determine the extent of damage on the glass surface. It removes the dirt, debris, grit, or road film that has stuck to the micro deformations on the surface of the auto glass.

 

Special auto glass cleaning liquids are available for this purpose. You can also use mild dishwashing liquid to achieve this task. While the glass is still wet, use a cleaning/detailing clay to pick up any remaining stubborn dirt or debris that’s stuck to the surface.

 

Wash again and use a clean rag to dry off the glass surface. You should preferably work on your auto glass inside a garage. Working in the open will increase the risk of debris and dust collecting over the glass surface and create problems at the end.

 

STEP 2 – PHYSICALLY OR CHEMICALLY SCRUB OUT THE DAMAGE OR MINERALS FROM AUTO GLASS

In this step, you will choose and apply an appropriate rubbing compound on the surface of the auto glass. This rubbing compound is abrasive (rough) and is usually mixed with water. If you are using a special kit you will have detailed instructions for use supplied with the kit.

 

It is advisable to follow those instructions. Chemical compounds like vinegar, ammonia, or diluted hypochlorite can be used to remove mineral deposits but these are not recommended by experts. There are however special solutions available by leading brands that provide safer and easier to use chemicals for cleaning mineral deposits.

 

Enough about chemicals, let’s get back to rubbing compounds and polishes. For those of you asking the question, how to remove fine scratches from windshields with toothpaste, your wait is over. White toothpaste, particularly one containing baking soda, is considered as a mild grinding abrasive paste that is cheap and available in every household.

 

You can use white toothpaste to coat a lightly scratched auto glass surface. Add some baking soda to it if yours does not have the stuff already in it. Scrub the surface by hand (if you are really up for a hard workout) or use a rotary power tool with foam or felt back to scrub the toothpaste on the glass.

 

remove scratches from windshield toothpaste

Begin with very low RPM and then raise RPM to finish the job. Toothpaste and baking soda eat at the glass surface around the scratch, leveling out the dip creating the damage. This usually does not require professional help and it also isn’t the choice of auto enthusiasts and professionals.

 

You will have to keep removing the paste and checking up on your progress. It is not uncommon to require several applications of the toothpaste mixed with baking soda to remove even the slightest damage on your windshield.

 

If you do not have access to power tools and you need to know how to remove fine scratches from windshields, the solution lies in using silicon carbide coated paper. You can use 1500 grit followed by 2000 grit silicon carbide paper under wet conditions.

 

For you will have to keep soaking the paper in water and working on the scratched area by hand. After you have smoothed out the scratches you will have to use a paste made from cerium oxide and water.

 

How to Use Cerium Oxide

Cerium oxide is a buffing and polishing compound used for removing mineral deposits, swirl marks, and surface scratches on glass. It is a white or salmon-colored powder that is mixed with warm water to make a paste for application.

 

Two parts cerium oxide to one part water ideal for windshield general scratch removal. For heavy restoration then use half as much water with two parts of cerium oxide as mentioned earlier. This will make a more aggressive rubbing compound.

 

For deeper scratches, experts recommend using a diamond paste instead. Cerium oxide should be applied using a cloth, sponge, or felt pad. It is harmful if inhaled and is not suitable for prolonged skin contact.

 

It works best if applied using a rotary or dual action power tool. You need to keep applying the paste to the cloth, sponge or felt pad as cerium oxide produces heat from friction and drones out quickly. A water spray is also recommended from time to time.

 

You will have to keep rubbing this on the locations you have worked on until it dries on the surface. Always remember to use light to medium pressure with slightly overlapping strokes to make sure that you are covering the required area.

 

Since you are only working out light surface damage you don’t have to worry about glass temperature, but just to make sure (especially if you are using a power tool) every now and then, use an IR temperature gauge to note the surface temperature.

 

Keep it below 120F ideally. If it’s getting too hot don’t use water. Just stand back and take a rest. You will perhaps be needing one already.

 
STEP 3 – CLEANING OFF THE RUBBING COMPOUND

After you have thoroughly worked the windshield or other auto glass surfaces where you saw scratches or swirl marks, it is time to clean off the rubbing compound you used. Whether it was toothpaste, cerium oxide, or a specialized rubbing compound that came in a kit, it should not be time to stand back and look at the fruits of your efforts.

 

You might have to go back to Step 2 and repeat if you feel that you can improve the final outlook or if you have missed some location or corners. To clean off the rubbing compound I would recommend that you use a wool pad and microfiber cloth.

 

Use some water to dislodge any stubborn material followed by a glass cleaning solution to ensure that the surface of the auto glass is absolutely clean once again.

 

STEP 4 – APPLYING A PROTECTIVE COATING ON THE AUTO GLASS

After cleaning your auto glass to a brilliant streak-free shine you should make sure that it’s protected from damage. You can use high-quality glass coating that bonds to the surface making it water repellant and scratch-resistant.

 

Specially formulated glass coating also makes it easier to clean glass surfaces. Another advantage is that the chemical composition of certain ceramic type glass coatings makes them anti-static and anti-fouling.

 

It is almost impossible for road film, dust, or other contaminants to attach to the surface of auto glass in particular windshields. Wipers also glide easily overcoated windshields without leaving streaks.

 

Dealing with windshield wiper damage and deep scratches on rear glass or car window glass

 

Wiper scratches on Windscreen

There are a lot of things that damage automobile windscreens. Scratches are caused by sandy dust particles (grit) rubbing between side window glass and seals, vandalism, road debris.

 

The most common reason for relatively deep scratches on automobile glass is using dirty or damaged front windshields or rear windscreen wipers. Windscreen wiper damage looks pretty bad, doesn’t it? Looks can be deceiving. On a scale of 1 to 10 for the difficulty of removal, if fine lines and scratches lie between 1 and 3, wiper damage ranges between 4 and 6.

 

You generally do not need an aggressive approach to repair wiper damage to the windshield. The easiest answer to those asking how to remove windshield wiper scratches is to use the 3M Glass Polishing Compound.

 

It’s the deeper scratches, those which snag the fingernail, which is the most difficult to remove without further damaging the car’s glass.

 

How do you get deep scratches out of a windshield?

Deep scratches, chips, or pits result from impacts with objects hitting the glass at high speed. They may also be caused by objects scraping against the laminated or tempered glass surface such as rings or snow shovels.

 

Rings are worn by people as they clean their cars can sometimes scrape the surface of the glass. Such scratches are aptly called “Ring Scratches”.

 

If these deep scratches are on your automobile’s windshield then I would recommend that you go to a car care professional to advise you on the best way to handle such damage.

 

Attempting to repair deep scratches on a windshield without proper training and practice may result in optical distortion. Perhaps you already know this, but for those who don’t, let me explain why.

 

Windshields are made of laminated glass. Unlike the rear windscreen or side glasses which are made of tempered glass. Laminated automobile glass is often made of at least three layers. It offers the highest degree of safety against injuries and visual clarity while driving on the road.

 

Two sheets of special glass with a thin layer of vinyl between the two. These layers are joined together by a process that applies a lot of heat and pressure. The outermost layer of glass is finally covered with an anti-reflective coating.

 

Another important factor to consider is that windshields are curved by design. The curvature depends on the make and model of the vehicle. When strong scrubbing (abrasive) methods are used for taking out deep scratches, the coating, curvature, and thickness of the glass can get changed by a lot.

 

This may result in optical dispersion, distortion, and weakening of the glass structure. All of these can pose a high safety risk on the road. Professional car care and detailing expert can judge whether the scratch can be safely repaired or a complete replacement is required.

 

For those of you wondering how to remove deep scratches from windshields, don’t lose heart. Chances are, that most scratches, including deep ones, can be removed.

 

In particular, those that are out of the driver’s immediate line of vision. An amateur detailing artist or even a well-prepared automobile enthusiast can use the techniques mentioned here to repair scratches that have not gone very close to the vinyl layer in laminated glass.

 

Deep scratches on windshields are best removed by using the proper tools and materials. Laminated glass is an incredibly hard material. Although it is possible to remove defects on this type of glass by hand, it can prove to be a very long and extremely difficult job.

 

A dual-action rotary power tool or right-angle angle grinder and even a hand drill can reduce the stress of doing all the hard work by hand. The next most important thing is a good quality auto glass scratch removal and repair kit.

 

Why require a glass removal “kit” here. Well, you could get each element separately, but I’m assuming you are a car enthusiast like me and don’t have much use of leftover stock from repairing or restoring your precious automobile’s windshield.

 

A kit usually contains everything you need to cover an entire car or SUV. It’s best to use fresh material that delivers the maximum benefits without losing effectiveness.

 

A good kit already comes with everything you need to fix the surface imperfections on your auto glass. You will usually get gloves, a microfiber cloth, and an appropriate rubbing compound for deep scratches. Some also include separate handheld felt pads for tight corners as well as glass cleaning and separate auto glass coating solution.

 

Glass coatings are also available separately and are recommended by top detailing and car care experts. They are quite popular because they strengthen the surface of the glass (against further damage) and form a water-repellant (hydrophobic) and anti-static film on the glass.

 

When properly applied on the outside these coatings make it easier to clean the auto glass and difficult for debris, dust, and other contaminants to stick to or etch on the glass. These coatings also allow your wipers to glide rather than scrub over your windshield. 

 

Enough about coatings here for now. You can learn more about them in our blog posts. Let’s get back to learning about rubbing compounds. A good quality effective rubbing compound always contains cerium oxide. A word of caution here.

 

Car windcress issue solving method

Please do not be tempted to use Aluminum Oxide based rubbing compounds. It is simply too aggressive and abrasive to use on glass. Although it is used by car detailing experts in very rare cases for glass, it is most commonly used on tire rims, painted surfaces, or on specific metallic parts.

 

If you desire a glazed mirror finish or want to remove fine swirl marks and scratches on the glass then you can also use an appropriate diamond paste. Diamond paste is expensive and at times also used in the detailing industry for the purpose of buffing and polishing.

 

With diamond paste, by using an appropriate grade (Coarse to Ultra Fine) and a high RPM rotary tool (7000 RPM or more at times!), you can start from a very hazy glass and finish with a superb mirror finish in almost no time.

 

The diamond polisher paste is mixed with a water-mixable oil and comes ready-to-use in a small syringe, with 25 – 90 microns (Coarse Grade) for rapid surface reduction, stock removal, and shaping to 6 – 14 microns (Medium Grade) for smoothing and pre-polishing and 3 microns (Fine grade ) and lower till 0.25 microns (Ultrafine grade) to produce a high luster polished surface.

 

Remember to always check the expiry date of the diamond paste. Certain active ingredients required to activate it fully may deteriorate over time. The stated shelf life of most diamond paste polishing products is about two to three years and just like food, the fresher the better.

 

Just as I described for fixing light scratches and wearing damage, taking out deep scratches from the surface of a windshield or auto glass also follows a 4 step process.

 

The only difference is that you have to put in an enormous amount of effort in restoring the glass, protecting yourself, and protecting the other parts of the vehicle. 

 

STEP 1 – CLEAN AUTO GLASS BEFORE WORKING ON IT

Wash the windshield thoroughly with a good quality car wash shampoo. Rinse all of the shampoo residues and dry the window before applying a special glass cleaning solution.

 

Wait a while for it to act. Then rinse again. If you have it (and if you are serious about having a super clean surface) use a cleaning clay on the still wait surface of the auto glass. Also known as detailing clay it is a very useful material used by professionals to assure near-perfect debris and dust collection from a surface.

 

Now dry the surface with a clean (ideally brand new) microfiber. You should now proceed to use duct tape and polythene sheets to protect the entire vehicle except the windshield or any other glass panel you are fixing.

 

Rubbing compounds that drip into the engine or door trimming or coat a wiper blade can spell disaster later on. Wear recommended PPE including gloves, goggles, and a respiratory mask before proceeding to the next step.

 

STEP 2 – APPLY RUBBING COMPOUND

Because you are trying to remove deeper more prominent scratches on the surface of the windshield or auto glass it is best that you begin with a thick paste of cerium oxide and water.

 

The mixture you prepare should look like toothpaste. Use a piece of foam or clean cloth to spread the paste in and around the area you are targeting. Now you can start using a dual-action rotary tool, 90o Angle Grinder, or hand drill with an M14 adapter to attach a soft buffing pad that is suitable for working on glass surfaces.

 

Start at low speed (e.g. 700 RPM) and move at a rate of about 1 inch per second in a circular overlapping motion. The biggest mistake you can make is to stop and work at one location longer than another one. Keep moving from the moment the buffing pad touches the surface of the windshield or auto glass.

 

As you begin to get an even coat of the rubbing compound, spray some water mist, and gradually keep increasing the speed. Maintain a constant light to medium downward pressure on the glass surface.

 

Keep applying fresh rubbing compound and spraying water until you see that the deep scratches are reduced and merged with the rest of the auto glass. Use an IR temperature gauge to monitor the temperature. Your aim is to keep the class temperature below 110F.

 

STEP 3 – CLEANING OFF THE RUBBING COMPOUND

Before cleaning off the rubbing cop you must allow it to completely dry off. This is the time when cerium oxide is bonding with and fusing with the imperfections in the glass.

 

Once you are sure that the compound is dry (usually 45 minutes depending on the weather) and coming off when you rub your finger on the surface, it is time to give the auto glass another washing. After a thorough wash using a special glass cleaning solution to make the surface squeaky clean.

 

STEP 4 – APPLYING A PROTECTIVE COATING ON THE AUTO GLASS

 

If you have carried out Step 3 correctly you will notice that the auto glass is appearing more optically correct. If not, then you need to begin Step 2 and 3. If you are satisfied, however, then it is time to apply the best protective coating you can get.

 

Some of the better ones on the market use fluorine and/or ceramic-based compounds that form a strong protective layer on the surface of auto glass. This type of ceramic coating for glass also makes it water repellant, dust, and debris repellent as well as glare-free.

 

Conclusion

Scratch removal from the glass panel is a very rewarding but moderate to high difficulty process. If you follow the steps mentioned you should be able to master its art and science and save a ton of money buying and installing a new windshield or rear glass. If you feel you have any questions or comments that can help you understand please feel free to contact us immediately. Drive safely!

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