david and Michael,

Thank you both for the lowdown on epoxy patching of this vile material.  What
are your views (and those of our esteemed colleagues) on use of patching
mortars?  I am working on a brownstone church (c. 1850, rebuilt after fire c.
1895) with a fair amount of delaminating/melting stone.  It has had some Jahn
patching but I am concerned that the only real way to do the job right is to
cut back the bad stone and install dutchmen (4" deeep or so).  Am I right in
thinking the mortar patching is at best a temporary (and if so, for how
long?) solution here in fabulous NYC, or... am I full of shit?

Thanks.

Ralph