First off it was a starburst chip that had 6 legs coming out of it. All of the legs where pretty small but 1 leg went out about 3 inches. No I didn't drill a hole, I approached it like I was filling any other leg but this was longer and had to take more time to flex, so what I did is I took the old tiny crack expander, the little blue one, and moved it to the very end of the 3 inch crack, I then went 1/8th of an inch further out and then dialed it down. I didn't put too much pressure, only enough to actually see the chip flex then I through a towel over it (so it didn't cure) and went looking for some more cars in that same parking lot. I came back and then washed all the outside glass on the car (exept the windshield) checked back on the crack and it was gone.
When you flex like that you can almost sit there and watch it fill, but you really have to watch because it is extreamly gradual. (Spelling sucks)
I then removed the expander and let it cure for about 5 minutes with the expander off, as it cured the last little bit of the crack I could see looking straight down at it was gone. Bye bye, so long, see you later. It was great, customer couldn't even find it I had to show here where it was...... the best part was... she still couldn't see it. As for resin's I used a thin crack resin on the chip as a whole. Also it doesn't matter if its a subsurface or complete crack this technique works both ways. I have been using this techique for about a year now and it works great. I still flex from the inside but this works better, you just can't do it all the time. David
Coitster