Skull with Brain

This is a skull with a brain in it. It prints with empty space around the brain. See the print I made with coke in it: https://youtu.be/4hr75JSFLsM

The skull model I used: https://www.blendswap.com/blend/10291
The brain model I used: https://www.blendswap.com/blend/13180

To put liquid in it while printing I used a syringe slowly putting the coke in it from time to time without pause (as the brain is a solid piece the printer works on it a lot. When it takes its time there I had an opening). But this is not a safe method.

What you should do: set up the gcode file so it has a pause at about 80%, put in the liquid and continue the print. Check out the layer view of the slicer so you have an idea when and where you can put liquid in, it helps a lot.