In the last moldmaking post, I had just finished and sealed this first inner piece. That’s my mold soap in the small tub with the blue lid, and the brush I use to apply it is there in the foreground.
In the next few steps, I’ll be making the rest of the inside pieces. First, however, I’m going to need to anchor some of this little guy’s floppy bits. Thin, floppy legs and tails are the biggest challenge when making plaster molds of small-scale models because they have too much give. This means the legs (or tail, or in Imp’s case even his pour spout) can shift when the plaster gets poured, and the final castings will be distorted.
This is where the Tacky Glue comes in. A tiny spot inside the mold cavity will hold the legs, tail and pour spout in place. The glue isn’t strong enough to create a permanent bond – in fact it peels right off afterwards. But most of the time it will hold everything long enough to get a true casting.
In this picture, I’ve poured the second gusset piece and scraped the plaster level.
Without taking the mold apart, I pour the poll piece as soon as the gusset is dry enough for me to flip the mold over.
Here are the inner pieces after they have set up. At this point I have become rather optimistic that this mold might just work. This is what the plaster mold will look like after the first piece has been removed, and I’m impressed with how easily it pulls. Perhaps I won’t need to make the second version of the mold after all!
I was also thrilled to see that my two gusset pieces separated easily, giving me a clean split.
I’m so optimistic at this point that I just barely avoid making a really, really big mistake.