Having neglected to take pictures at good times of the last few stages of the female firewarrior project, I had decided to not even mention them on the blog. I'm regretting that as now I have to play catch-up. I finished up the initial scuplt and made a mold of it. Which took three or four days (most of which was spent waiting on silicone to cure). Then a handful of casts. This is the stage where I learn a lot about my sculpt and usually where I do a lot of revising on it. The image at the start of this post is the mold of the first cast.
As usual, I decided I didn't like a large chunk of it and using one of the cast pieces as the base, chopped off large chunks of it and redid them. I tried getting some pictures of the new scuplt, but it kept ending up with greenstuff work on a white blob. The lighting was just unable to pick up any definition on the unpainted white resin.
So instead as I mention casting relatively regularly, so I figured people might be interested in my particular methods. I use 2 different methods depending on if I'm making a one part or two part mold. I'll plobably cover one part molds later, but as I need to cast the reworked FWF torso I'll start there. I build an interlocking brick box (I think these ones are megablocks) and then roll out a blob of clay.
I press the part in the clay, press the building brick box around the part, and lastly add some divets using the 'wrong' end of a paintbrush to work as keys. I would use some other method besides clay, but I'm poor and haven't gotten around to hunting down and pricing out some of the temporary mold materials.
The silicone I'm currently using is made by GE Silicones and is "RTV426" with catalyst "Beta 26". I got a 5 gallon pail of it as a sample from them a while back. I'm assuming they're used to dealing with people that use multiple gallons per cast as that's a LOT of silicone. Their datasheet suggests 3 different mixes, and I aim for the 100 parts silicone to 3 parts catalyst as I almost always add too much catalyst (bringing making the actual ratio about 100 to 4) which is halfway between 2 of the suggested ratios. I mix it up and drizzle a tiny dab onto the part which I carefully spread into the cracks of the model (sorry, forgot to snap a picture at this stage) before slowly filling the mold with the rest of the silicone. This helps us poor mold makers without vacuum chambers avoid bubbles.
It then sits for 24 hours to cure. And that's the first half of the 2 part mold. I'll cover the second part as i do it.