I use to do what you asked and I would make my tails and then the next day or a few days later I would use them and they bonded fine for me. I wondered what people were talking about when they said if plastic cured you could not bond another half or they would come apart. They were right, when I tried with the bodies doing half and half, if I let one half cure first they would split right in half. Not sure how I got lucky with the tails, but I wont be trying it anymore. I will from now on do the whole process at one time