Don Mosley wrote:
Which glue would be best for this outdoors?
Plenty will stick it but I'm worried on cheap mirror it will eat the silvering
off the back.
This is mirror tile on cinder block then I'm putting old wood window frames on
top. Spruce the wall up a bit. With trees in front it looks pretty cool.

Mirror mastic. Comes in cans and caulking tubes. Make sure you do a
good job of sealing the edges of that frame to protect it from
moisture. You also may want to coat the edges of the mirror to keep
moisture from working its way in and tarnishing the silvering.

R