A retired mason pulled me aside at a job in Akron and showed me how to check a brick with a tap
I was laying a garden wall on a house in Akron and a retired mason named Walt wandered over from the neighbor's yard. He picked up one of my bricks and tapped it with his trowel handle, then told me to listen for a flat clack instead of a ring. He said he had been at it 41 years and that a ringing brick means a hairline crack inside. I had never even thought about sound before, I just looked at the face and chucked it on the wall. Then he watched me lay 3 courses and only said one thing, that my bed joint was running about 3/8 inch instead of the 1/2 inch on my gauge. I have been tapping bricks ever since, so what is the one old trick you still use from someone who trained you?