I wouldn't use Liquid Nails. But, for what it's worth, regular silicone aquarium sealant, though it does not bond well to acrylic, is fine for some situations.
I'm using a 20g tall as a sump, and attached 3 full-width pieces of acrylic to serve as baffles/bubble trap. After doing a freshwater test, I decided to lower the baffles. It was quite a task getting the baffles out! Of course, the silicone off of the acrylic a lot easier than it did the glass, but a thick bead held the baffles in place just fine.
90g AGA Reef-Ready; 20g sump; 12g refugium; ASM G2 skimmer; 2x Maxijet 1200; Quiet One 3000 return pump
2 Ocellaris Clowns; Nassarius, Cerith and Strombus snails; Scarlet, Blue-Leg, and Zebra hermits.