It didn't cure at all? How much catylist was added? How old was the catylist? How much time has passed?
If it didn't cure at all, then it woudl eventually run off the sculpt onto the table, leaving only a thin film remnant. If it partially cured, then you can pour fressh stuff on and it will cure beneath the fresh layer.
My guess is that the mix was off ratio, or th ecat was old, as it decomposes faster than the resin (B side)