How do you all sand your shinai?
Did you know there is a specific direction you should sand your shinai?
Firstly, when you take your shinai apart, you should see all the nodes on the shinai.
Use that node as the starting point and always sand or shave towards the tip of the shinai.
If you want to sand the tsuka side, sand towards the bottom of tsuka.
By doing that, you can sand or shave along the fiber of the shinai.
If you go in a opposite direction, you will be sanding it against the fiber's direction. So you might accidentally sand it too deep.
It will go in very deep especially if you are using a shaving knife.