Walter R. wrote:
I would like to glue some 4x4 ceramic tiles (house numbers) to my
entry door. (Covering up some discolored areas.)

The door was previously coated with satin spar varnish. Will any glue
hold on the varnish, if so, what kind of glue should I use?

Can you put them in a (custom?) frame then screw the frame to the door?