Hi All,

I would like to make an epoxy granite beam that holds a linear rail. I am planning to use this recipe, found here[1]
He speaks about 67% sand, 33% dust, 14% epoxy. In my mind this converts to 57.6% sand, 28.3% dust, 14% epoxy (all by weight). For the dust I'm planning to use this [2] aluminum oxide powder, and this [3] brand of epoxy

Now I know I can't machine epoxy containing sand and dust. So I want to create this cake:
Top layer: pure epoxy.
Base layer: epoxy granite.

To be able to drill and tap screws for the linear rails, I'm planning to embed vertical columns of rebar in the epoxy-granite layer, (flush with the boundary between the two layers) as this steel can be machined / tapped.

How thick must the layer of pure epoxy be to let it self-level into a smooth surface?
Is this the optimal way to do it?
Cheers,
Cedric

[1] https://youtu.be/gjw5juGG1g8?t=1062 Epoxy granite stiffness - test and results
[2] https://www.keramikos.nl/chemicalien...xide-1-kg.html
[3] https://giet-epoxy.nl/product/dikke-...poxy-giethars/