On 21/11/2017 13:08, sm_jamieson wrote:
My fireplace is made of tiles - stuck over a former which seems to be
a mix of concrete and iron strengtheners. The tiles were originally
stuck by bedding in some type of cement product that is very tough
and I cannot remove it without damaging a lot more of the fireplace.
So I need to "glue" back the loose tiles. The fireplace is not used
much and will not need to withstand very much heat.

The glue needs to be very thin so the replaced tiles are not
noticeably proud of the others - so probably not epoxy or contact
adhesive, or tile adhesive.

What do you have against epoxy? The standard slow cure stuff will hold
well enough on ceramics and works best with a very thin layer.

You want the original slow cure stuff - it goes quite runny and spreads
very thinly shortly after mixing. 5 minute stuff no good for this - you
need a decent working time with it and you may have to support any tiles
which have gravity working to pull them off for a few hours.

You might want to put a spec of TiO2 pigment in to make it white (or buy
the white version which is more expensive). The default clear/straw
coloured stuff will be slightly visible in a fine crack otherwise.

--
Regards,
Martin Brown