Just a quicky...

Maybe two actually...
1,I have lots of spare White marble. If i grind it all down with a file, is this adaquet (sp?) sand for my intonaco layer?

2,What if i have walls that are old plaster or drywall, but instead of laying concrete or whatever method one may use to apply fresco upon such a space, what if i crosshatched with a knife, gouging the entire surface of the wall creating a tooth forthe plaster to stick to, then sanded it down smooth, would this be well enough for the lime to stick,and maybe get around having to go through one of the more orthodox processes?

Just wondering. Thanks guys, im just getting started, though passionate and in Love I am.