In the past I have had a lot of difficulty with a number of plastic welds except the kind that comes from Wal-Mart in the black syringe, called Devcon Plastic Welder. I have had two or three syringes of a different brand (clear syringes) and for some reason it seemed that they NEVER set. However, the Devcon seems to work VERY well and as Andy said, when that stuff sets, the pieces are never coming apart.
Still, I am totally intrigued by the acetone and ABS approach! I need to find something to try this with!