Good grief...earlier today working on this form I found if I make it too quick the internal clay (even though the outside is drying) starts to move and slump down over the lower layers. I have had to cut off about 3 hours work as I was going too fast for the clay to dry internally . Strange how clay demands that you work it in a particular way...back to the nature of materials.
what's also interesting is that as it dries it shrinks onto the pipe, so I need to add paper around it to get it out.
I quite liked the incidental construction marks I was getting lower in the form where I dragged a fork over the surface to pull the clay coils into each other.