What is Thickset?

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?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.