I'm working on some plaster carvings, following the steps in the answer I was given about making plaster.
These blocks dried in their container for about 8 hours, then have been air drying for another 48, as of this morning.
Last night, they were fine. As of this morning when I woke up, even the carving that I started has its sharpest edges turning orange. These edges do not match the edges of the initial mold. They seem to be the most completely dried portions of the plaster. The thinness of the edges might have sped up the drying process, which could be part of the issue.
As of now, about 7 hours later, my WIP carving has started turning white wherever it has dried out.
I used blue, liquid food coloring dye.
Why are my edges turning orange? What could I do to prevent it?