OK, all you sharpening wizards, I have a question about sharpening at the other end of the scale. Let me explain.

Every July for the last decade or so, I have served as crew chief for excavators digging mammoth fossils in the Black Hills of South Dakota ( here). One of my routine jobs is to sharpen tools, typically chisels, pointing trowels, and putty knives. Typically the tools dull rather quickly, as we are digging in fine grained sediments. I often will sharpen the same tool twice a day.

The current "sharpening" technique consists of running the edge along a medium grit bench grinder, taking care not to burn the steel and occasionally dousing the tool in water. My interest is heightened because I have just acquired a hori-hori, a Japanese tool fashioned specifically for digging dirt. It is rather dull, and I am sure sharpening will improve it. but I am thoughtful about the best way to put a good edge on it. The blade is inscribed "K245 Stainless China'" which is probably not in the same league as S30V. Any inisghts are welcomed - What is the best way to sharpen an edge for really rough work in dirt and rocks?