Various burs are used in the windshield repair business. So how do you select the right bur for the job and get the most mileage out of that bur?
The first enemy of bur service life is heat. Because the drilling head on these tools is small, it does not take much friction to build up a considerable amount of heat in the metal. If you've ever mistakenly touched one after using it you know what I mean. They can get hot! Drilling at a high speed or for a prolonged period of time both contribute to heat build. The larger the drilling head of the bur the better it will be able to withstand the effects of heat which is what makes the Tapered Carbide Bur a good all around choice.
Another foe of the carbide bur is debris from previous drilling. Bits of glass, dirt and even the polyvinyl butyral laminate can become stuck to the bur and will work to wear it down if left. To clean the bur before or after use simply use a lighter to burn contaminates away. Now, as we just discussed, heat harms as well so use the flame sparingly. You need just enough to burn away contamination and no more.
Drilling into the laminate layer of a windshield can also destroy your bur in very short order. It's not the laminate material (PVB) that causes the problem, but the fact that as the bur penetrates the inner surface of the outer layer of glass it tends to bind up causing the tip to snap off. Not only have you ruined the bur, but you need to find a way to extract the piece of metal from your customer's windshield. Needless to say, the repair is not going to look all that great as a result. Delta Kits does not recommend drilling into the laminate! A good way to check the depth the hole is using the depth gauge on the Spring Hammer.
While drilling is not required in every situation, getting the most out of your burs is still important. Remember that Delta Kits technicians are available to answer your questions.