I'm in the midst of making prosthetics for the "Home Sweet Hell" shoot tomorrow, the stuff just arrived this morning - a day late. Obviously time is something of an issue here. I finally got time to run a batch an hour or so ago, figured, it was a little humid I should cut way back on the gelling agent - the gelling agent is basically what it sounds like, it's the shit that makes the foam gel, and when it gels it goes from a meringue kind of texture to a solid, rubbery wet blob.
Complicated mathy/science stuff warning!
The instructions recommend at 50% humidity, 15 grams of the gelling agent. I find it gels too fast so I normally do about 10 grams. This normally gives me about 5-6 minutes to get the foam into the mold, add on another 2-3 to finishing mixing the foam and you've got around 9 minutes before it turns to crap.
Well, it was 75% humidity in here, I added about 6 grams and it gelled in about 2 minutes. I didn't even get it out of the mixer and just suddenly went from a perfect batch to a solid, ripped up, rubbery blob in about the span of 5 seconds.
I guess they weren't kidding about humidity being a critical factor. I just ran another batch, barely 1 gram of the gelling agent. It's been about 20 minutes and it's still gelling. I guess I'll see how it works this time eventually.