"Existential Angst" wrote:
-snip-

Bear in mind that I have three types of repairs:

IMO--
missing mortar in a stone wall, on the order of cubic inches of volume per
patch;
Type S mortar
spaces in flagstone on top of a stone wall (1/8-1/2" wide), and slate
walkway cracks of about the same;
If that mortar grout matches, I might use it here-- otherwise Type S

and very fine cracks around existing slates/mortar in the walkway, patio,
porch.

I wouldn't touch them. Wait until they are big enough to risk the
mess. [or rip them out and re-grout if they bother you]


Will thinset do ALL of this, or just the finer cracks?

I'd only use thinset to level and bond- never to patch.
[I am *not* a professional- maybe they would]

Jim