Since this building required no insulation, a lightweight concrete made from pumice was used. This structure was built by Leslie Feuerborn. Les is an architectural artist.
One interesting and powerful idea in forming structures with a mold is that the mold or form can have textured relief cut into it. Various architectural designs can be incorporatated into the mold to create designs in relief when the wall is cast. Notice the ceiling design. In this case, the relief was further enhanced by antiquing with ordinary latex paint.
To create these designs, the originals were carved in wax on the master mold. The master was then duplicated using Densite K-12, an industrial plaster. Fiber reinforcement was added to the densite to make the forms for this structure. The form edges and ribs were 2 x 4's. Talc was used as a release agent. Much too complex for most of us.
After experiementing with PVC forms, we have settled on EMT conduit and double-ply polyethylene or vinyl (from used billboards) to create the sectional forming system as shown on the forms page.
In our search for a low cost mixing system, we have settled on a spiral-whisk mixer of our own design. For years we made similar spirals with lighter materials for transporting materials in tubing. This is a heavier version. It is simply a spiral whisk made of metal stock wrapped around a small diameter pipe. It works quite well for mixing slurry and perlite without doing damage to the lightweight aggregate. It doesn't have to be perfect, off center and out of round a bit just makes more whisk action. Works well in a 5 gallon plastic bucket or even in a wheelbarrow or mixing tub without spilling or splattering. It can be spun both ways.