Field sharpening -
 

Always carried three knives after awhile -

Pocket knife of some sort for fine work - i.e. Swiss Army model.

H2H knife of some sort - not to be used for anything else if at all possible - i.e. Gerber MK I.

Field knife of some sort - sturdy and with correct blade geometry for EZ honing in the field, if necessary - i.e. KA-Bar Fighting-Utility Knife.

I found a stone as provided with many Randall Made knives worked just fine.

And when the quick and small ceramics came out I added one for the quick touch-up capability.

All very inexpensive, lightweight, compact when and where space on kit/body armor or rucksack was/is concerned.

Sharpening update!
Last week I had the chance to hand sharpen a Spartan Harsey folder that had been used hard daily for over a year by a building contractor. Some pretty tough stuff had been cut with it and the edge had some dull spots.
Sharpening was done the owner watching.

I have a Norton two sided stone on the bench, the orange colored fine side is aluminum oxide and the other is a dark grey colored medium silicon carbide.

My report is that the silicon carbide side cut the CPM S35VN steel very well, restored the edge within my "job" attention span (which if that runs out I go to the belt grinder) and some finish work on the orange side of the stone had the knife paper slicing sharp.

Cutting a piece of printer/copy machine paper by drawing the length of the blade from base to tip in a slicing cut is a good way to test for flat spots on the edge that need a bit more work on the stone.