The "just lay it dry" crowd is wrong and my Tuesday pour on Elm St proves it
Everyone on here says you can lay block dry and come back to point it later, but last Tuesday on the Elm St garage job in Akron we did exactly that and the mortar shrunk a hair overnight. Next morning 6 of the 40 blocks had hairline cracks at the joints and we had to grind and repoint the whole run. Lost half a day and I'm still not convinced that shortcut is worth it. Anyone here honestly get clean results laying dry in summer heat, or is that just something people repeat?
Watched a buddy try the dry lay method on a retaining wall out in Stow last August and he got the same thing you did. Eighty some blocks, and by the next morning a bunch of the joints had cracks you could catch a fingernail on. He ended up tearing out about a dozen and redoing them because the cracks went deeper than just the face. His take after that was the heat pulls the water out of the mix too fast, so the mortar sets up before it really grabs the block. Now he keeps a spray bottle handy and points as he goes, never comes back to it. Sounds like your Elm St job was the same story, the shortcut just does not hold up when it is hot and dry out.