On 05/08/2010 11:03, Jim K wrote:
On 5 Aug, 09:51, stuart wrote:

Tile adhesive sticks to virtually anything from the glazed surface of
other tiles to old lath and plaster finishes. Failures are usually due
to too much adhesive and/or not combing it with the spreader, which

allows air to pass between the ridges.

eh? shurely the "slight twisting motion" as you press on firmly is
going to flatten those ridges down into a full bed?? that's the point
of the ridged applicator/trowel i.e. to achieve a consistent ideal
depth of adhesive on the "ideal" flat wall..

Jim K

But the twisting motion is only slight. If you take old tiles off you
can usually still see the grooves in the adhesive.