Well???? We have thinset mortar for tiling; Is thickset the stuff they
use for bricks?

Actually the above is just frustration (although I would like to pin
someone down to an answer). I absolutely, positively have to install a
marble saddle, 52 * 7 3/8 * 1 1/4 before Sunday. I cleaned out the old
one -- fell apart in my hands; probably not really marble -- and the
six inches of rubble underneath exposing the wooden base and then
filled the trench with 5000 psi (must be good, eh) Quikcrete to a
level where the concrete + the saddle will be within 1/8 of an inch of
the base of the double doors. So far so good. I then sealed the
concrete with UGL's Masonry Treatment since it has been drummed into
me that under no circumstances can concrete be allowed to dry for -- I
don't know -- ten years or so g. Bad idea, in fact bad idea all
around.

Now understand I've never used thinset in the past, preferring to rely
on that impervious-to-water much-easier-to-use mastic but this time I
thought I'd try the really good stuff -- millions of tile setters
can't be wrong; or can they?. After getting filthy rummaging through
the bags of thinset (hasn't anyone in the concrete/tiling industry
ever heard of plastic?) and wading through a list of cautions/warnings
longer than CA's cancer-causing product list, I find that I can't use
thinset anyway because I'd have to let the concrete cure for 28 days
and as for the Masonry Treatment I shouldn't have used that either
because the thinset has to be used over a porous surface. Sheesh...
how do any of you ever use this stuff? Taking my bathroom out of
commission for 28 days is realistic...NOT!

So is it back to the good old mastic or does someone have some really
great idea on how to break my thinset cherry?