Clear silicone caulk works great for this.
Glue mosaic tile to mirror.
On jan 28 2017.
Most mosaics intended for indoor use such as this mirror can be made using weldbond and sanded grout.
Weldbond is the best.
I ve done this on mirrors several times.
I used it to clue the moulding around my builder grade mirror and it worked beautifully.
Weldbond adhesive 160ml 5 4oz the best mosaic glue made.
I prefer to paint the glass black.
It s very easy to work with and easy to remove.
Pp opount 2360 pieces self adhesive mosaic tiles square glass mirrors mosaic tiles mirror for diy craft decoration 5 x 5 mm 4 3 out of 5 stars 77.
It s a water based pva glue has no fumes dries clear and water resistant bonds to most any surface is non toxic and cleans up easily.
You can use either 100 silicon or a knife edge grade epoxy for your adhesive.
If that is a negative then you could paint the backs of the tiles a flat black or mask the area of glass that will not be tiled and use a flat black paint to paint the part of the mirror that will be covered with tile.
Measure and mark the center of the plywood square.
Found mine in the caulking section at hd.
Aivs self adhesive glass craft mini square round mirrors mosaic tiles stickers for diy craft decoration 5 x 5 mm 7200 pieces 4 6 out of 5 stars 143 17 99 17.
Get it as soon as wed jun 17.