I was just at Home Depot and noticed how many different epoxies they had. You know those 5 minute ones in the double syringe? They now have "Extended Cure," "Metal/Concrete," "Gel," and, you guessed it, "Plastics"!!! I don't know if it would work for acetate or all plastics, though.These epoxies aren't great, but they can really be helpful when you only need a little drop or two, or need something that cures real quick, but is better than superglue.
My pennies.