AC glue is a water-based, cyanoacrylate glue that sets extremely fast. It has as many uses as the user can think of. In the following example I’m using it to quickly adhere a template for a circular drywall cut for a in-house sound system. See photos below.

I placed some blue tape to act as a barrier between the activating agent and the ceiling.
I also placed some blue tape on the template and added the AC glue here.
The glue instantly bonds to the activating agent causing an immediate bond.
I used an oscillating saw to cut out a circle for a speaker.
A good cut! The template is easily removed from the blue tape. A great way to get the job done without damaging the ceiling. In addition, I can reuse the template for other speakers in this home system.