Bryan...I've not used the DIY version,but I do use a repair kit in my work.
If you can, gently heat the windshield from the inside while applying the pressure from the injector. This will help the resin flow a bit better.
Also try and do it in shade as the resin cures with UV light. this will give you more working time.
I also apply pressure to flex the damage from the inside but it's a risk as too much can make the chip/crack worse!
Let us know how it turns out.
Jock
