Hi Max, great response. You are really making this a vivid discussion.
Clayplaster has been a succesful approach for over 20 years of masonry heater builds here in europe.
It is super simple. These are the details to pay attention for:
- use fiber mesh and always asure an overlap of 10 cm between each row of mesh.
- make sure you embed the mesh in a fresh coat of plaster.
- make sure your mesh is running around the corners of your stove.
The fiber mesh works as steel in concrete. It connects all the pieces into one solid structure.
Base coat can be up to 1 or 2 cm thickness.
Finish plaster up to 2 or 3 mm.
In this way you will never have any cracking issues. Guaranteed as long as you are using an expansion joint.
Trust me, every masonrybuilder is doing it this way over here. And I did a lot of clayplaster on stoves and strawbale houses as well.
Have a look at www.vuurmeesters.nl for example. They started using claybricks and plaster and build hundreds of stoves in all kind of shapes thinkable.