Casting n00b here...

[Wargoul]

I'm trying to make a mold of the chassis of a Furby so that I can slap some sculpey on there and bake it without it losing shape. I had the two halves all wrapped up, put plaster on them and they came out relatively fine. However when I poured the plaster for the cast in it fused itself to the mold and I spent a good 4 hours making a big chunk of plaster.

How can I avoid this? I'd also appreciate it if you could give me some beginner's tips so this sort of thing doesn't happen again.

[SavannaLeigh]

You need to use some sort of release agent before you pour into your mold. The releasing agent will prevent the cast from sticking to the mold. It's very important when pouring plaster into plaster, because they will always want to bind.

There are some homemade soap mixes you can use to release, but I'd recommend brushing on thin layer of Vaseline. There are also some commercial mold releasing agents you can buy, Smooth On makes some good ones: http://www.smooth-on.com/Release-Age.../c9/index.html

I usually use their aerosol can of Universal Mold Release. I've never had any problems with it.

Good luck!