Volume 15, Issue 5- September/Octobert 2013
Do the Two-Step on a Hot Windshield
When repairing a crack you always want to terminate the crack into a tapped bullís-eye. If the crack goes past the bullís-eye during repair then you must go back and do it again after it cures. If you do not do this, you are left only with the chemical bond of the resin to prevent the crack from spreading.
When the crack is terminated into a tapped bullís-eye, you have both a mechanical stop and a chemical stop. When you drill the point of an edge crack on a hot windshield in the hot summer months, the crack might jump past the bullís-eye when you go to tap your bullís-eye. Or the crack might travel past the bullís-eye when you repair because the glass is hot, so here is when procrastinating can pay off.
Most repair techs like to start a long crack repair at the point and work toward the edge. With the two-step method, you work from the edge to the point.
It is best to do long cracks inside so you can cool the glass and prevent any premature curing of the resin by the sunlight. If you are working via a mobile unit, get the vehicle in the shade and open the windows. This will cool the glass to the ambient temperature in the shade within a few minutes. You must block the sun from the windshield completely and be careful that the sunís rays do not bounce off the hood on to the windshield.
Start the repair by placing a crack opener a few inches from the point. but do not put the pressure bolt to the glass yet. Prepare your tools with edge-crack resin and medium-crack resin. Place the sliding crack repair tool in the middle of the crack then slowly turn the bolt of the crack opener near the point to the glass and apply slight pressure. Now go to the edge, and injector-slide edge crack resin going toward the middle until it stops. Then pick up with the medium crack resin and slide toward the point until it gets less than a half-inch from the point. Stop clean with the resin in the crack at a 90-degree angle in the crack (Note: This is easily done with proper crack resin).
If the resin does not stop clean and at a 90-degree angle it will leave a spot (cosmetic blemish). Remove the crack opener and cure. After curing, the crack has been bonded and pulled together so you can now drill and tap your bullís-eye without it jumping past the bullís-eye. You now have less than a half inch to repair the same way you repair a stone-break. Drill the point, tap your bullís-eye, mount your tool and do the remaining inch or less just like a stone-break. As always cure under pressure to prevent a void in the bullís-eye. You can see a video of this method on Youtube.
Richard Campfield is the National Windshield Repair Association president, as well as the founder and president of Ultra Bond Inc. in Grand Junction, Colo.