When detailing a car, there’s one aspect that often gets overlooked: the glass. And while the glass in your home windows might look the same as the clear stuff in your car, that’s where the similarities end. Commercial glass differs from application to application, and there are even different materials in use in cars’ windshields and side windows.

Cleaning automotive glass without damaging it requires the right materials and techniques. Overlook either of these two things, and you’re likely to either damage the windows or waste your time. Make sure you clean them correctly by following these steps. 

First things first, have the right tools

Obviously, you wouldn’t use household glass cleaner on auto glass. Always use an ammonia-free and alcohol-free cleaner for auto glass. Using ammonia in a car’s interior can dehydrate the materials and cause cracks and discoloration.

To apply and buff off your cleaners, always use a microfiber towel, just like you would for detailing the rest of the vehicle. Never use paper towels, which will contribute to scratches in the surface of your glass. The softer material and electrostatic charge microfiber towels create will help remove particulates from glass, rather than just spreading them around. If you need to remove particularly gummy residues, you can use mineral spirits or grease remover.

Use the proper technique

How you apply and buff off your window cleaner is every bit as important as the cleaner you use if you want to ensure a quality finish. Consider your working environment. It is best not to clean glass in high heat because cleaning products can evaporate and leave residue.

Use separate towels to apply and remove cleaning products, and quarter your towels to help apply pressure when removing dirt. Use a straight up-and-down motion, rather than buffing in circles, when you remove cleaning products. If your towels get dirty, have extras available to swap in.

How you move around the car is important, too. Begin with the windows on the driver and passenger side doors, rolling the windows down at first to get the glass that is hidden when windows are completely rolled up. Roll the windows back up and finish cleaning the window.

Continue to move around the outside of the car, cleaning the windshield and any side glass. Don’t forget to clean those side mirrors, either. Move inside the car once you complete the exterior glass. This is where things can get tricky because interior glass tends to be more difficult to see dirt on. If you are perspiring from washing the car, or it is warm where you are working, try to cool down the window interiors to prevent residue from other cleaning products.

Special cases

If you are detailing the whole car, you’ll want to consider when you will apply these products and when you will clean the windows. You’ll want to either allow cleaners to dry or apply them later and then retouch the windows. This is particularly true in cars with leather interiors that will receive their own cleaners and treatments.

Water spots are one of the most frustrating parts of cleaning windows. A soft toothbrush and window cleaner can be used to remove these. Better yet, use deionized water to clean the car if there are high calcium levels in your water. This will keep windows from spotting when you clean them with soap.

How to treat chips and scratches

Damage to a windshield is a serious matter, so it’s important to make an accurate evaluation about whether a windshield can be repaired before taking the next step.

Bullseyes and small cracks can often be repaired. There are kits available that will help you inject sealant into the damaged area so it dries clear and doesn’t compromise the windsheild’s integrity. Crack repairs are possible too, though they’re more difficult to get right, so be sure you feel confident going into the project.

Enjoy your reward

Clean glass is what makes a detail job pop. Polish up the headlights and side markers, and wait until last to clean the rearview mirror to ensure there’s no residue left from interior cleaners. Make sure to get the clear plastic in front of the gauge cluster clean. Shine up the brightwork and interior trim and black out those tires.

If you follow these steps, you’ll provide your clients with perfectly clean, clear glass that will have them coming back for more. That’s a great way to drive your business.


Scott Huntington is a writer and automotive enthusiast from Harrisburg, PA. Check out his blog, Off The Throttle, or follow him on Twitter @SMHuntington