Autoclaved Aerated Concrete for High Temperature Tooling?

I have been interested in the idea of using autoclaved aerated concrete (AAC) for composites tooling but until recently I never had a chance to test it. In fact I had never even seen in first hand! Finally got my chance thanks to Aercon AAC. They sent me a 12″ x 12″ x 4″ sample and this video shows the results of my first experiment!

It works! There is some question on how to seal the porous surface and I haven’t got a reliable number on the CTE. But it held up and seems to have come through the cooking process unharmed. The big deal is how much cheaper AAC is than most other high temperature tooling products! A pallet of AAC costs about the same as a single 50mm thick sheet of epoxy tooling board. More to come!