Seesee

Since you have a deadline, it may be impossible to remake the piece in time. In that case, I would go ahead and fire the piece. Those cracks are not likely to expand to the point of destruction unless additional stress is put on it during the firing. You may need to accept the modifications to your piece as part of the process, maybe even emphasizing stress lines with glaze or coloration to incorporate them - an “I meant to do that” approach 
If there’s a possibility of completing a new piece in time (using and improving on what you have learned so far) I recommend that you make two or three at the same time as insurance, or at least the greater likelihood, of a piece completed as you envisioned. And maybe you’ll have a series! 

Initially I wanted to make 3 peices so if this happened I’d have options over the span of a month I only completed this peiece to a level that I was happy with. (the others warped, cracked came apart) So was distraught when I broke it and then these cracks appeared. I fear I’ve learnt nothing from the process but to never build intricate geometric forms by slab building. I have 3 weeks left and will just try my best to get another one done this time using the thicker slabs and another clay with less grog. I do like your idea about embracing the stress lines although I hope that the glaze I use will fuse everything together. Overall just disappointing that’s it’s not structurally a strong peice which also has an impact on aesthetic, also that I feel I’ve learnt next to nothing. Thank you all for your help! 

Hi Morgan 
No I never got into the habit of wiping my pieces down before glazing as I’m usually in such a rush to get things in the kiln. This was some time ago when I used to work in a studio and the piece didn’t reach full temp so I refired it and this is what happened. I reckon I contaminated it with moving it from A to B but will take more care in the future. I thought it was something to do with firing it twice! 

Thanks so much, I will try to look out for this in the future

This might give you a better idea of some of the issues involved in getting the deflocculation right.

Determining Dispersant Additions for Casting Slips
https://static1.squarespace.com/static/527ac372e4b0d4e47bb0e554/t/527fd7f1e4b0c046bfa9b90d/1384110065234/Dispersant+Addition+Procedures.pdf

Hey Hulk
thanks so much this is definitely the problem I started rotating the moulds so that the walls would have a even thickness and now no slumping! A lot of trial and error with different slip consistencies. Annoying how the consistency in the tubs need adjusting but I got there in the end!