Pacific Rim Slattern Statue
 

Why do they blowtorch the statue like that? What does that do to the surface and what does it allow them to do after?

My guess is to dry those areas out to avoid it from deforming and drooping. The heat from the flame will start to bake the clay a bit.

Actually it's a smoothing effect. I'm pretty sure they are using a product called Castaline which is a putty/wax hybrid. You need heated tools to sculpt but you can also cut and sand the sculpt in it's raw form. By running that blowtorch over the sculpt it takes out any rough tool lines and gives it a more organic look. It does make it melty and the follow-up step they didn't show was the sculptor blasting the heated putty with a can of compressed air turned upside down to freeze the castaline in place. I've seen this technique used on Chavant by Simon Lee (same guy who designed the Kaiju) while he works on his sculpts.
Castaline is supposed to be the new sculpting medium in the toy industry because it uses the classic wax techniques while being tougher and it's supposed to be super light weight so you can do big sculpts without it collapsing on itself. It never dries out so it can be reused bu that also means the master sculpt is susceptible to heat and breakage.

Thanks. That's some good info.

Cool, glad it was informative. Here is a video of the guys at Neca, they don't talk about the process much but you can see them working on the Castaline masters...

The Secret Story of TOYS on Vimeo