In article ,
Lobster writes:
On 26/04/2012 17:44, Andrew Gabriel wrote:

Depending on the quality of the back of the mirror, the acetic
acid given off during curing of silicone can wreck the silvering.
There is a special mirror equivalent which does not risk damaging
the mirror silver. A glass shop will have it, but I think I've
also seen it in one of the sheds.

There are actually different sorts of mirror adhesive, as I found out
not long ago. Both come in cartridges; one sort is similar to silicone,
and you apply thick parallel beads of the stuff all down the back of the
miror; when you apply it to the wall it needs the weight supporting for
a good while till it cures (I use a batten screwed to the wall) and you
need to take care that there's a decent thickness of adhesive twixt
mirror and wall (I use spacers behind the mirror to ensure this), and
that there's free flow of air to all the adhesive so it all goes off OK
(ie a big spiral or concentric circular beads are not good).

The othet type is an impact adhesive; you spread a thin film on both
wall and mirror, wait 5-10 mins and apply the mirror to the wall; and
that's it, stuck. No support needed.

I prefer the former type myself as my walls are rarely (never)
billiard-table-flat, so I'm more confident that the adhesive is actually
doing its job!

I have used one of the no-more-nails type products, but that was
in a case where the mirror had a plastic backing, so it wasn't
going to be able to react with the silver. It was an IKEA
bathroom cupboard where the door was a mirror glued to a wooden
frame (but not originally glued well enough).

My parents have a full length bathroom mirror which was fixed
to the wall 30-40 years ago with double-sided sticky pads.
I took it down a year or so back whilst some work was done in
the room by gently pulling away so the sticky pads failed, and
then refixed with new sticky pads. The originals came with the
mirror and were presumably chosen not to damage the backing.

Last time I fixed a mirror to a wall, I used the edge fixings
which screw to the wall behind the mirror, with a small metal
bracket to hold the edge of the mirror, the top ones sliding
into place after positioning the mirror on the bottom ones.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]