I'm doing drywall work around where the outside corner of my tray ceiling vertical meets the regular ceiling. I bought paper-faced metal corner beads and spray adhesive thinking it would be quicker than nailing it up. I followed all the directions: I let the adhesive get tacky before installing the bead, firmly pressed the bead in place on the wall/ceiling, continued to press it to the wall/ceiling for the next few minutes, and then waited half an hour before the first coat of mud.
Now I've got a crack in the mud running the entire length of the bead, and the bead is "spongy" to the touch. If I push against it, it gives between 1/16-1/8" or so, and doesn't feel solid. I figure the crack is from the rather thick coat of mud I applied to make the corner square, but I don't think it should have that much give to it. Should I tear it out and use a nailed-in corner bead? Or will another coat of mud somehow fix the problem?
EDIT: I tried driving screws through the paper-faced corner bead, but the metal in it wasn't as thick as a regular one, and the screws tore right through. I ended up tearing it down and nailing up a regular corner bead. When I was removing the paper-faced one I discovered that some parts of the adhesive had stuck well enough to tear the paper on the drywall, while other parts weren't sticking at all. The only explanation I can come up with is that I didn't prep the surface well enough, although I did wipe it down before applying the adhesive.