Ever had one of those moments of sheer, utter astonishment, where your mouth drops open all the way down to your ankles and stays there?

That was me on Monday, thanks to the artwork pictured above. The rightmost panel quietly separated itself from its hanger and came off in my hands…while I was rehanging it. Since it’s been hanging perfectly well on that same wall for more than three years, I was, uhm, kinda taken aback.

I made this triptych back in 2007, and described the process on this blog. These aren’t small pieces; they’re about a half-inch thick and 10×36 inches apiece. They’re also probably my favorite abstract frit painting, which is why I hung them on the fireplace wall in my office. I used the Hang Your Glass hangers, one per panel, and they’ve hung there quietly for more than three years.

I took them down about three months ago to be photographed and then to spend one evening with kitchen and bath designers.They’ve been sitting in my studio, well-swathed in bubble wrap and carefully packed in a carryall, ever since.

Yesterday my friend Rinee stopped in for a visit, asked where the panels were, and we trundled downstairs to put them back over the fireplace. I carefully set the first into its wall mount, peered around the back to make sure it was secure…and the entire panel came away from the hanger and slid into my hands.

That’s when my jaw hit the floor.

If I’d simply slipped it in and walked away, would the panel have fallen onto the granite hearth? Or fallen later, in the middle of the night? Only a tiny smidgen of cured adhesive remained on the hanger–the rest was still on the glass. If there was a problem with the surfaces (Hang Your Glass glue hates any kind of grease), or the glue was old, why did it wait MORE THAN THREE YEARS to fail?

We decided not to hang the other two until I figure out what happened (duh). But I’m wondering if traveling or being stored weakened the adhesive. Or if it aged. Or if maneuvering on and off the hanger added some shear force that weakened the bond…?

I do know that I’m not rehanging the other two until I figure out what’s going on. And I gotta admit, I’m now wondering what might be happening to all those OTHER pieces I’ve mounted this way. Sigh. I’ll call the HYG people and see if they can figure it out.

In the meantime, ideas, anybody?