IIRC, Rust Oleum's instructions say to do it in the reverse order that you did it (Etch then patch). When I did my garage, I did my acid etch on a sunday afternoon and let it dry until friday night before using the patch. I let it dry for about 10 or 12 hours before using 60 grit sand paper on a random orbit sander. The sander knocked down the high spots and gave it a little texture. If you do this, make sure that you vacuum the residue to keep it from hindering the bond between the slab and the epoxy.