getting bullnose edge on marble slab

["George Graham" <georgergraham@xxxxxxxxxxx>]

Teitel,

The first rule of sanding down marble is that getting through the first grit
of sandpaper  will be equal to the amount of time it will take to go through
all the rest of the grits you would go through to polish the stone. Because
you started with a very rough grit, 50, you may have some deep white lines
that are below the surface. Using a grinder can "bruise" the stone because
it hits the stone, causing damage below the surface. This really shows up on
dark stone as white marks. The only thing you can do is stay on 80 grit
until all the 50 grit scratches and marks are gone.

Once you have gotten the shape you want with your grinder, try using another
tool. A belt sander used lengthwise with the edge works good. Stay with 80
grit until done, then go through 120, 220, 320, 400, and 600, making sure
all scratched from the previous grit are gone before going to the next finer
grit. The last four grits will easily be done by hand, (with water), if you
have done a complete job with 80 grit.

It takes some experience to recognize when you can move on. Inspect your
work wet and dry.

I've got one nagging question , is it possible that you are working on a
piece of granite? If so then what I just told you to do will take forever!

Finally, 50 grit is very rough to start on 3/4 inch marble. Next time start
with 80.

Good luck, be patient, and don't despair!
George Graham