Clean uncured resin from prop to remold

[CharlesHouse]

I did half of a twosided mold using Smooth On Mold Star and used clay I thought to be non-sulfur. It seems that everywhere the clay touched, it didn't set. It was sticky on the surface, so I took a razor and cut the surface off and intend to redo the registration keys and surface of the mold. However, the surface of the prop itself is covered in goop which I assume will screw up the possibility of it molding properly. I want to clean this off and then spray with acrylic paint to seal it. I spent a half hour in the shower with liquid dish soap scrubbing the mold after cutting the sticky section and the prop, but it still has uncured silicone on it. How can I remove it in a way that will permit the next layer of silicone to cure?

 

[cavx]

What is the master made from?

I might suggest you use Acetone, but given that stuff destroys most things, be very careful before using it. You don't want to use it if there is even a hint of a chance that it will dissolve any detail on the master part.

 

[CharlesHouse]

Plastic and painted. I don't want to mess with acetate since we plan to remold.

We are having trouble figure out how to remold it as well. Basically, I have half a mold with a rough surface and no keys. I'm trying to figure out how to replace the keys and a consistent surface so we can make the other half.