Kidding. I prefer putting molds into the pressure pot before I go to sleep. This way I don't have to listen to the compressor kicking on while keeping the contents of the pressure pot under the correct PSI. Otherwise, I'll put molds under pressure if I have other things to do outside of my studio. Seriously, if I don't have hearing-protection for this, it will eventually cause damage to my hearing, and I can't predict when that compressor goes off. ^.~
On to the mold making. ^____^
Like always, set up the workspace. This way you aren't scrambling for materials. Because I've been busy, there's a couple of extra molds in here. The white piece on the left is being molded without pressure. The parts to be cast under pressure are the ribs, human aaron, waist, and human alice. I only have so much space in my pressure pot, so not *all* of these will end up being poured tonight.
While setting up the workspace, go turn on the compressor. That way you aren't waiting for it to pressurize when you want to pop a mold into the pot.
Also scraping the last bit of silicon out of my last bucket, which is why there's two containers on the table. What was left in there wouldn't have covered much, but every drop is useful.
Normally you take a stab at mixing up the amount of silicon needed for the mold. In this instance, I'm pouring four molds, so I'm doling out as much as I can comfortably and consistently mix. This time I actually snagged a shot of the silicon weight. It's in grams.
Normally you want to mix in by weight 10% of the catalyst (blue stuff). The more catalyst mixed in, the quicker it sets up. I tend to mix in 15%-20%, this is why the numbers are so 'off'. Some of my molds have set up in less than 5hrs, which is pretty fast. Then again, I'm pretty much in optimum mold making conditions. ^.~
In the back you can see that I was moving the molds around. That was so they'd be easier to grab when I was ready to start pouring.
Before it's set up, silicon has pretty much the consistency of cool honey, and is about as friggin sticky. The ribs were a little tricky to pour, since i had to make sure that I didn't get a large air pocket inside the piece, which would translate into an ugly bulge of resin when cast. As it was held at a 45degree angle, the silicon was poured into the 'cup' and allowed to 'overflow' into the rest of the mold before being set back down and filled the rest of the way. Granted, it would have been loads easier if I'd poured from the bottom.... but hindsight is 20/20.
The previous 2cups of silicon that was mixed up only served to complete the molds for Alice human, Ribs and about an eight of the Aaron mold I'm starting now. Another two cups were quickly mixed to complete the Aaron, and also pour the remainder to complete the Elf Alice head mold which isn't being cast under pressure. So, what's in the pot are ribs, Alice human, and Aaron human. Tomorrow I'll be able to pull the molds, and make a pressure cast of Alice and the ribs. ^.~
