If it is water based, I would try a scrubber/buffer, the big ole fashioned
kind that is used for comerical floors, for buffing and stripping wax, my
local home depot rents them, get some of the corsest pads they have, and
some simple green and water, put some down and start scrubbing, I have had
the guy at the rental store in home depot tell me people use them to clean
off slabs in prep for tile and other floors to go down to the slab, and I
think running a big buffer is pretty fun also.
stay away from the high speed models, they are used to buff out the wax, but
buffer is a generic term for most of them.
Good luck

"SteveBell" wrote in message
...
My client wants ceramic or porcelain tile on her back porch. The
previous owner had glue-down green carpet/fake grass there. My question
is: Can I put thinset down on top of the remaining skim layer of carpet
glue?

An Internet search gives me advice all over the map: remove it with
solvents/don't use solvents because they soak into the concrete and
keep thinset from sticking; remove it with abrasives/don't because it
just melts and wastes time; remove and replace an obscenely thick layer
(1/4 - 1/2 inch) of concrete.

* The surface is smooth and even, and it is sloped properly.
* I power-washed it awhile back, and the glue washed off just slightly.
* I plan on scraping with a 4" razor in any case.

The fact that the glue dissolved slightly makes me hopeful that
water-based bedding material will "bond" with it. On the other hand, it
makes me worry, also, that it won't.

I'll take any advice I can get.

--
Steve Bell
New Life Home Improvement
Arlington, TX