My grandpa's old sharpening stone just made my tools duller.

A buddy of mine had a similar scare with a pipe behind a wall. He ended up using soapy water in a spray bottle on all the joints he could reach. The tiny leak made a bunch of bubbles right away. It's a cheap trick but it saved him from tearing out drywall. He said listening didn't work because the leak was too slow to hiss. Sometimes the old ways are still the best for those hidden spots.

Yeah, saw something similar in a book on early American binding. Those flat spines rely on really tight sewing. The whole structure is different. Tried it once on a dummy text block with linen tape instead of cord. It felt solid but opening it was stiff, like it fought you. Makes you wonder if the durability comes from never really being read much back then.