The following blog post is a short synopsis of the effort it took to finish up these molds. It was a grand total of 2.5 days. We were spending 8-12 hour days to complete a majority of the work.
We started on a Friday evening, where we spent four hours building the necessary walls to hold the molding material in place, with the appropriate keys. The walls are built up of clay. And we poured the very first layer of molding material -- alignate. (This foundation layer had to completely dry overnight for us to work the next several layers.
Saturday, we poured multiple layers of more material to cover the plaster heads. Each subsequent layer would protect the previous one..
There was a lot of downtime in between, as we waited for the resin to dry, so each of us brought multiple projects to work on while we waited -- some worked on costumes, some on prosthetics, and I just knitted.
We also did a lot of cleanup while waiting --- getting all of our tools & containers cleaned for the next layer.
We finally poured the last layer, which we let cure over night. Everyone climbed into their own respective beds way after midnight, exhausted.
The next day was all about resin & fiberglass. We started by cleaning and preparing the semi-finished molds.
We donned all of our safety gear, including two layers of gloves and respirators. The resin is particularly stinky, and not conducive to breathing. We did all of this work outside as there wasn't any industrial fans to suck up the fumes.
Fiberglassing the molds was grueling work. The resin & fiberglass are extremely sticky, and we had to work fast before the resin set.
We worked on a single head at a time with 3-4 people frantically layering fiberglass. Each head took about 40-60 minutes to complete. We would rotate 2-3 people in-and-out in order to give people breaks. We basically worked non-stop. As the heads were taking so much time to complete, we wanted to get done before the sun went down.
When one head finally was dry enough (about 2 hours later), the excess fiberglass was cut away. This process was a tricky one, because you had to time the drying process correctly. If the fiberglass was too wet, you couldn't cut it, but if it got too dry, it would have been impossible to cut.
Of course, this process isn't completely finished. The fiberglass has to completely cure, and then we can separate the fiberglass from the alginate molds.