The new crucible is now invested.
I have invested the crucible in 1800 castable refractory and shaved off the edges of the insulating bricks (image above). Now I am working on the former for the dome. Image above shows the base completed. The images below show the crucible surrounded by the insulating bricks, filler brick being cut to shape to fill some of the space round the base and the inside of the bricks coated with mortar.