Jason,
I find that the 4x36 has limited usefulness in knife making. Here are the main uses I have found for it
1) Removing excess resin from freshly stabilized blocks
2) Flattening the sides and spine on a blade
3) Sanding the pin down to the level of the handle
Otherwise it is too big and underpowered for most of the other sanding and grinding I do.
- Greg