Tim Fischer spake thus:

Hi all,

We're just about to start a small tile job (45 sq ft bathroom). Last night
we tore up the ugly vinyl tile floor. It came up pretty easy with a heat
gun. The concrete slab underneath is in great condtion, but is noticably
"tacky" from the vinyl tile adhesive. We're not talking globs of adhesive
or anything, in fact it isn't really visible at all, except for a little bit
of gloss here an there and some other discoloration of the concrete. But
nothing like big black or yellow/gold blobs of adhesive like I've seen
elsewhere.

So my question -- will my thinset stick to this, or should I attempt some
sort of chemical strip? We used some household cleaner (409) and a wire
brush, then mopped with a strong floor-cleaner solution, and that helped a
little, but it's still quite tacky when you feel it or walk on it.

To get rid of the residual sticky stuff, I'd use some low-impact
petroleum solvent: either paint thinner (*not* remover) or charcoal
lighter (naphtha). These are relatively benign, will probably dissolve
some, but not all, of the sticky stuff, and can be removed with any kind
of soap or detergent. (You can use low-odor paint thinner if you're
concerned about the smell.)

After that, if any stickiness remains, try using denatured alcohol
(shellac thinner) the same way. I've found that it sometimes takes a
combined attack of naphtha and alcohol to get rid of certain sticky
substances. As above, wash the alcohol afterwards, though most of it
will just disappear through evaporation.


--
Napoleon won the battle of Waterloo. The German Wehrmacht won World War
II. The United States won in Vietnam, and the Soviets in Afghanistan.
The Zealots won against the Romans, and Ehud Olmert won the Second
Lebanon War.

- Uri Avnery, Israeli peace activist
(http://counterpunch.org/avnery09022006.html)