Lessons learned . . .

[rescue]

Well, picked up some new knowledge today.

First job - a crack behind the mirror on a Range Rover. The owner said he accidentally bumped into it. The crack had legs in all 4 directions - north, south, east and west. The upper crack ran to the edge of the windshield. I drilled the other three legs and ran the cracks into the holes. Didn't miss any. Then I noticed that one of the legs somehow continued through the newly drilled hole. So I drilled another hole to stop it. Then I applied the crack jack to the first crack, and it did the same thing! Just ran right past the hole. I consulted with the owner who really did not want to buy a new windshield (looked expensive, it was a heated type windshield with a fine wire mesh embedded between the layers). So I drilled another hole on the bottom leg. Applied the jack and again it ran right past the new hole! Well at this point I told the owner that I couldn't do anything with it, and that he'd have to replace the windshield. LESSON LEARNED: apply only very, very light pressure to the jack in the vicinity of the hole.

The second job was a small (mini) bullseye combo with batwings. I didn't drill it, but applied the injector. After the first pressure cycle, the void filled partially. I flexed the glass and of course one of the legs grew about an inch! So I continued to flex the glass to try and get resin to flow into it (it didn't appear to be flowing). Just at that instant I received a call on my cell phone. We talked for about 5 minutes. When I went back to work on the break, to my amazement it had filled in completely! LESSON LEARNED: if on the pressure cycle you can't get it to fill, be patient!

Someday I'm going to be an expert! :eusa_wall

[Dave M]

Rescue,
You say that the customer bumped the rear view mirror which leads me to believe that those cracks were on the inside layer of glass, not on the outside. This would explain why the cracks jumped thru your drill holes. Had you popped a mini bullseye in your drilled holes? Of course, that would not have made any difference if the cracks were on the inside!
Also, use caution when repairing a heated Range Rover w/s. Inspect the break very carefully to make sure none of those tiny little wires have been damaged or broken. Also use care when drilling this w/s (don't drill into the wires).
Prior to repairing this w/s I notify the customer or dealership that there is a possibilty that those wires could be damaged and no longer function properly.
I believe there was a memo out regarding these w/s with the heating elements. I'll have to dig into my paperwork unless someone else has it handy.
Very expensive w/s, around $1000....HAVE NOT HAD PROBLEM DOING REPAIRS!

[Clarity Glass]

I second Dave M's diagnosis (absolutely perfect in my opinion). The wire info is also spot on. I use the opportunity to inform my customer of my knowledge of that particular window and the damage that can be done unnecessarily. Perfect opportunity to gain their trust and all that's left is to perform a high quality repair.

[toab]

Rescue..Re-first job..Were these cracks that long that you had to crank on the jacks.I generally just use the jacks on long cracks over 3-4 inches.Generally speaking of course.

[rescue]

Thanks for the replies.

That's an interesting idea about the cracks being on the inside. I am pretty sure that they were on the outside, but I wouldn't bet my life on it. I was able to flex the glass from the outside and run the cracks into the newly drilled holes. The cracks were no more that 6" long.

I did drill the holes all of the way through the outer layer. This was to prevent the crack from spreading past the hole. Didn't work. Regarding the wire mesh- I don't believe that drilling into the mesh and/or actually cutting one of the thousands of tiny wires would cause any damage to the heating function. The mesh is a large grid which acts as an electrical resistor. When current flows through the mesh the wires heat up ever so slightly - but just enough to melt frost. If one wire gets cut, this wouldn't stop the flow of electricy through all of the other wires. The windshields on jet aircraft are also heated like this. By keeping the windshield warm, it is stronger and more impact resistant.