Late last night as I was cleaning up my desk I noticed something a little bit weird. Both of the good casts I've pulled so far had swelled in the middle, just bloated up. My guess is because they had some air trapped inside them and it got so hot in here the air expanded. It didn't happen for at least 24 hours after they had cured. So from now on, as soon as a pull has completely hardened, I'm going to drill a small hole directly through the center so the air has a way of escaping. This should solve the problem. If anybody has some molding experience and can offer me up some tips on how to keep the air pocket from forming at all, I'd love to hear it.