The Science Behind the Dollar Bill Test

A side view of the windshield on four black cars

If you’re not in the glass industry, you may have never heard of the “dollar bill test.” We interviewed our Glass Doctor® corporate office’s technical director, Tommy Patterson, to get some insights into the science behind this industry term, and to investigate how Glass Doctor goes above and behind industry norms while replacing or repairing windshields. See our questions and his responses below:


What is the Dollar Bill Test for Windshield Repair?

Some companies use the dollar bill to determine acceptable repair size. We do not repair anything we cannot cover with a fifty-cent piece.


What is the science behind this concept?

Other repair shops believe they can repair a break the size of a dollar bill without affecting the integrity of the windshield. This may very well be true, but the jury remains out. It is our belief that a repair that large would adversely affect the structural integrity of the glass, and might therefore jeopardize the occupants’ safety. This, coupled with customers’ general displeasure with repairs this large, are the reasons that we feel our standard for repairable breaks is best.


How can consumers know whether it’s best to get their windshields repaired or replaced?

Bring your vehicle into the nearest Glass Doctor franchise office. We have professional teams at-the-ready to give you our professional assessment on whether windshield repair or replacement is needed.


What kind of windshield repair training is offered at the Glass Doctor training center?

We offer training on two of the most widely used and accepted systems on the market today at our Glass Doctor Training Center in Waco, Texas. This includes the GlasWeld Ecovac system and the Glass Technology Spectrum system.


Why are Glass Doctor specialists the experts when it comes to windshield repair and replacement?

We believe we are the best there is because we care so deeply about the safety of our customers and base our repair decisions on that concern. If we feel a repair is either in an unsafe location on the glass, or that the repair will result in a loss of structural integrity of the glass, we will choose to replace it as opposed to repairing. 


Again, always focusing on our customers’ safety and satisfaction is paramount.