Comment by ido
1 day ago
I did not appreciate having to pound the dust out of the erasers when I was in grade school.
I wonder if they could make the chalk magnetic and have magnetic trap at the bottom or
something. But again too complicated.
The Russian solution is to use water - wipe the board with a wet sponge.
The german way seems to be a wet sponge followed by a squeegee to wipe off excess water. Here's a masterclass from Frederic Schuller (and a rigorous advanced course in quantum mechanics)
https://youtu.be/GbqA9Xn_iM0?si=Cy7EQOvPtoRqgmhc&t=1070
Germans also squeegee their blackboards.
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.
That sounds way better
Wait, you don't use water?! As a German I kind of thought that's normal everywhere, dip the sponge into water, clean the blackboard. Slamming dusty sponges together sounds.. very dusty indeed.
Well, I only ever cleaned them fully in grade school. In undergrad I TA'ed on whiteboard, in grad school it was unfortunately all whiteboards. Except for the rare literal "chalk talk" mini-conferences I was fortunate to attend, where I just erased what I had at the end, no full cleaning. So, I guess I just never "saw how the sausage was made" and implicitly assumed the worst.
Or my grade school never knew better, which is quite possible given its size/location. Or they thought it was funny to make kids deal with all the dust?