Comment by crazygringo
1 day ago
In my school, the board was erased many times throughout the day with erasers, and then with water only at the end of the day so it would be "pristine" the next morning.
If you wipe with a sponge, you can't really go on to use it immediately can you? Like you can't write well on a moist chalkboard?
I had a great calculus prof who would wash all the chalkboards halfway through our (3-hour) class, and dismiss all the students for a 10-minute break while the boards dried.
I've had teachers that'd waft a binder at the board while continuing to talk. you can get a decent part of the chalk board dry in under a minute doing that. It's not like you're getting the board soaking wet either. A whiff of water is plenty to clean the board.
Edit: note you can also write on a wet chalkboard just fine. The tactile experience is just a little worse.
Squeegee like sibling comments mentioned, then it doesn't take long to dry.
We used moist chalk to leave stronger duster-resistant marks on the board.