If you don't want to expose a lot of aggregate, try using some automotive wet/dry sandpaper #200, #400, #800 and do it by hand. Has worked well for me.
Hey Blair, I didn't clue in right away how to reply to you. The sink is supported by 2x4's along the two walls and by a diagonal-brace bracket at the free end. All the supports were put in before the wall was covered in cement board. The back edge is only 1.5" thick, and the space between the edge of the sink bowl and the side of the slab is hollow. That's the part that rests on the bracket.
I used 3 ladder wire pairs along the bottom of the sink bowl, bent up the side of the sink bowl, across the horizontal section and down the exposed side wall of the vanity. It was interesting to bend the wires, I think we discarded more than we kept.
Hey Blair,
I have tried Buddy's mix in a sprayable face coat and it works well. You just have to sift out the small aggregate with a window screen. As far as the 4"and 6" fronts that I've been doing, those are all wet cast or pressed and the fronts are 1.5" thick.
I have been going thinner with my BR pressed finishes by doing a think press and mixing GFRC fibers into my back coat. It works well and you can get down to 1 1/4" thick, saves on material and weight.