Bob I used a piece of screen wire like you have in a storm door over a bucket pushed it down into the bucket about 2 inches. I think I used duct tape around it to secure the screen. Its been a few years ago. put some stone dust into the dipped down screen, I used a spoon. Shake the bucket and move the dust around on the screen with the spoon. remove the large stuff and repeat. It is very fine. From a powder to probably scale 3 inches. I have never actually measured it. You can get a good idea of the size from the pics especially the one of the front of a light Mikado (next to last pic)How fine is it Les? What do you use to screen it? We have an asphalt company and gravel company very close here. Might be worth a trip.
Bob