One thing I had a hard time with was getting the guy on the mixer to use the same recipe (sand, mortar, water) every time and making the tenders understand that adding water on the mud boards (shaking it up) when it started to get too stiff to use was a no-no. Shaking up the mud will change the color of the mortar. I was working on a school and I told the guys this and the contractors' son said "don't tell me that you can't shake up mud." He was used to building warehouses. Anyway, they made mud before going to lunch and shook it up when they got back. There was a band of different colored brickwork one month later when it had cured. The school board inspector complained about it. He said it was from shaking up the mud. The son and I never got along after that. He thought I ratted him out. I didn't. Plenty of horseshit jobs in Florida, I got another one.