how to cut flat base on stone

[Simon <simon@zzzzzzzzzzzzzzzzz>]

Dulce,

Don's advice on boning the block is impeccable, as always. But have you tried
using a flush mounted diamond blade to create a flat bed on a boulder?

It is simply a normal diamond cutting blade either with holes drilled around the
arbor to fit a flush mount e.g.
http://www.granitecitytool.com/showitem.cfm?itemnum=434&catnum=81&pcatnum=112

or with an integrated mount e.g. http://www.mytoolstore.com/mk/bdrygen.html#flush

You cut the same depth as normal, then knock off the waste and repeat across the
entire surface.

There are two tricks to using this type of blade.

One: make sure that you always use a guard, this may mean adapting an existing
one, or building the flanges up so the blade is flush with the guard rim.
Recently, during an awkward cut, I had a 9" saw kick back into my chest. Because
the blade was guarded, it only tore my shirt.

Two: when you are using it, let the face of the blade skim lightly across the
surface to maintain flatness.

Simon