Well looks like a round of the flu in the family and the holiday was enough to halt the project. So today I was finally able to resume. Decided on a 3/4” thick silicone jacket to make this mold very durable for what will hopefully result in a higher cast yield, even though it means using more silicone. In hindsight I wish I would have tried 5/8” thickness, however, I know from prior experience 1/2” would have been too thin with this process of first making the fiberglass shell. Fingers crossed!