Made four test pucks today.
1. All clay.
2. One part clay one part ash.
3. One part clay one part sawdust.
4. two parts clay one part ash one part sawdust.
The clay was a clay slip about the same as pudding.
Now the hardest part waiting for them to dry.
I will keep this updated as I get results.
I should add that this mix will be used to make a burn tunnel like matt walker did for his house. I also plan on adding fiberglass like he did in his cobposite. I hope he doesn't mind me stealing his ideas.