Isn't snipper the injection specifically marketed for preventing "gumballs" on Liquidambar styraciflua?? If so I think Sherrill sells it, I'm sure they'd have info available, or whoever makes it surely has a website. Do some searching around, even on here I know it's been discussed. If I remember, timing is everything. Seems like a lot of people favored florel as I think it is a spray, and involves no drilling. I've had some customers interested, but I've never messed with it. The customers want to not pick up any "gumballs", but I don't think snipper is advertised to be 100% efective. That's why I stayed away. Someone pays you whatever you charge to prevent their gumballs, but if 30-40% are still there I think they'd be upset. Just dig around here a bit, see what you come up with and if you do try it, let us have some pics and check back later with the results.