lamellar ground silica

[glaskrafter]

It's me again, with questions about casting molds.
I've a Potter friend who had a bag of Novacite 550 silica that he got for glazing back in the last century (1990's)
I've been playing with the idea of using this very fine silica with my plaster for the face coat in my casting forms
with the hope of getting a finer surface on my castings.
I Goggled the Novacite to make sure that it was actually pure silica only to find it referred to a
"lamellar ground silica", further stumbling in Goggle told me that it is the shape of the silica crystals that is
being referred to.
I was wondering if anyone had any experience with this. Or has tried finer silica for their face coats for a
finer glass surface on their finished casting.

[Stephen Richard]

My understanding is that silica sticks to glass. Not sure if it will work as face coat, but others will know.

[Greg Rawls]

From a health perspective, crystalline silica is nasty stuff. If you are going to use it dry keep the dust down and wear a P100 respirator.