Hello everyone. Several years ago I started experimenting with some large scale starship playsets for the 3.75" or 4.5" figures. I used styrofoam to make the basic shapes, and covered it with a glue and cloth mache that is very strong. I wasn't happy with how the first attempts were progressing, and eventually had to throw the incomplete D-7 away during a move.
This wasn't a great success either. As each casting gets progressively bigger, it gets distorted, loses fine detail, and becomes more expensive and difficult to mold. I think the hydrospan method is only useful when you're only planning one expansion, or when your original piece is organic in texture. So, no 4" Defiant from the Playmates model ship...
Here's the thing...right now, lots of artists are sharing information about large scale fabrication in the cosplay world. Some amazing prop guns and suits are being crafted from foam, woodboard, and bondo. Has anyone else been following these artists? I think their techniques could be adapted to making big ships.
We should all try this, share information the way cosplay enthusiasts share info!