I haven't found any hard and fast rules on how much stropping should be done. There are quite a few variables at work. Here are a few of those variables:
1. Sharpening a knife will often leave a small burr. Stropping can remove this small burr, but the time it takes will depend on the size of the burr. If you can feel the burr, just keep stropping until it is gone. A 30X Radio Shack lighted scope can be invaluable at locating the burr, if you cant feel it.
2. Some steels are much more abrasion resistant than others. One steel may only need a few passes on a strop, to reach a certain level of polish, while other steels will require many more passes.
3. The intended use of the knife is a big issue. Push cuts work better with a very high polish. If you do a lot of push cutting, you may need to strop for a longer period of time.
4. What youre stropping the knife on can make a huge difference. Stropping a knife on a piece of cardboard is much different than stropping on a piece of 600 grit wet/dry paper.
5. The grind of the knife will also effect how much stropping needs to be done. A convex grind, when properly maintained, is stropped much more often than it is sharpened on a hone. If you let a convex ground knife dull too much, youll either have to take a stone to it, or do a heck of a lot of stropping.
In the end, each knife is its own animal. You can become a master of stropping a certain knife, and be completely in the dark when it comes to a new knife. I ran into this when stropping my old 52100 Marbles Fieldcraft, and then stropping a newer Alchemite MC Marbles Plainsman. While the grind of the two knives were similar, the steel was very different.
by rounding the edge, so I don't strop much. But do let us know what you find out. I'd like to know how much stropping it takes to undo a good sharpening.