Many thanks for your comment!  (Apologies for my delayed reply.)

These panels were attached using a combination of Liquid Nails/PROJECTS, and Silicone II.  The Liquid Nails grabs almost instantly, holding the panels in place.  The silicone takes

Many thanks for your comment!  (Apologies for my delayed reply.)

These panels were attached using a combination of Liquid Nails/PROJECTS, and Silicone II.  The Liquid Nails grabs almost instantly, holding the panels in place.  The silicone takes longer to set, but when it does, it's longer-lasting because it remains flexible.  (BY "combination," I mean a few dabs of liquid nails/Projects, and siliconeover most of the backs of the tiles--The two are side by side, not mixed together.)  Other sealants that "grab" fairly instantly will work as well.  I also used the silicone as sort of a grout around the edges of the tiles.  This seals them off from moisture getting behind them (which could later freeze and expand) while staying fleible unlike real grout; however, the silicone does get dust/sand stuck in it--not as clean a surface as is desireble.

The rectangular panel at the far left is one of a series of six that continues inside the building.  Those are flanged steel panels.  They're attached...