Hey gcljlamb, if you’re using the wet method, maybe you have hard water. If you’re not and putting it down dry, maybe there’s something wrong with the air in your town. I would advise getting some air samples and dropping them into an airtight plastic bag [or a vacuum] and sending them to a nearby army base and have them test it for illegal aliens. That’s what is probably getting behind your vinyl.
However, if they go away at night, then I think they’re local illegal aliens and not from outer space, but from below the border. You see, these little devils get behind the vinyl when you’re not looking and disguise themselves as sign shop vinyl adhesive with an out gassing rate of 436, 900 dytrons a second. At that rate they can flee as fast as a few hundred in a single night. This is a technical term that we’ve adopted in the sign industry as ‘BUBBLES’ You don’t want them. No way, No how !!
:Oops: Uh-oh, is this gonna turn political now ??