Last week I started making plaster molds to help a relative. I'm already able to make single and double pieced molds but I'm having trouble with a relatively complex vessel. I attached a 2D representation of the sliced vessel.
1 - How can I mold that inner border at the top?
2 - Can someone recommend a tutorial/book/video on how to cast molds with more than two pieces?
3 - For how long should I keep the mold drying before trying to cast?
4 - I tried to use mineral oil to keep the plaster pieces from merging while making the double pieced mold, but sometimes they merge either way. Is that the correct oil to use?
5 - Do I need to apply mineral oil on the plaster before casting the slip?