Sharpening steels or green compound which to use?

[DavidL41]

Im curious why some people go straight to compound and strop like for razors and hunting knives and chefs use a sharpening steel.

What is the actual difference in sharpness between compound or a finishing stone vs a sharpening steel. It seems like the sharpening steel (I have not a lot of knowledge on this) is to remove the burr quickly but does it go back to the same sharpness or gradually lowers every time they go to the sharpening steel, is this the same with compound, you use it a few times and once it rounds the edge you go back to a 5k stone. Am I on the right train of thought?

 

[HeavyHanded]

You're sort of on the right track.

Sharpening steels come in two varieties, a Butcher's grooved steel, and a smooth Meatpacker' steel. The grooved one works like a file and actually grinds steel off, the smooth one works by plastic deformation and refines the edge that way. Both are very critical of angle, and neither work terribly well on the relatively high RC that most pocket and sport cutlery possess. Kitchen cutlery (Western) has hardness levels far lower, in the high 40's to low 50's. The smooth steel can only refine/touch up the edge so many times before the edge experiences brittle failure from being work-hardened, or from being hit at ever increasing angles to keep getting a good effect. The smooth steel can still work on higher RC steels for finishing, but the grooved ones (in my experience) do not work well once the steel gets much above 50 RC. Even should they manage a fresh edge, they lack the abrasive potential to cleanly remove the burr most of the time. On softer steel they work very well once you have some familiarity.

Whether compound rounds the edge over time or not will depend on how hard the backing and surface are, and how much force is applied. Along that same vein, once the edge experiences damage or wear greater than the compound can repair, you should go back to a stone. There is a huge variety in how various strops work based on the variables. Technically the honing block I make (link to site in my signature below) is used like a strop, but work more like a fine hone. It can repair a great deal of damage and maintain geometry before one needs to go back to a stone.

 

[DavidL41]

thanks heavy handed. Using a 12k stone or higher does that replace green compound?

Do you typically feel with your fingers if you need to go down to 4k stone, look at the edge or some other way? I would imagine its by feeling the edge but would like to hear your take on this.

 

[HeavyHanded]

thanks heavy handed. Using a 12k stone or higher does that replace green compound?

Do you typically feel with your fingers if you need to go down to 4k stone, look at the edge or some other way? I would imagine its by feeling the edge but would like to hear your take on this.

Really fine waterstones can often replace a strop, anything about 8k and finer will be very refined and crisp. The Green CrO edge might be a bit more refined assuming it was sharpened way up to a high finish and then stropped gently. One has to have a need for that sort of edge to justify the added time in. IMHO other forms of really fine hard stones will still need some form of strop, even if its something as mild as newspaper. One can get by without but takes (me) a lot longer and requires more QC.

My current sharpening set-up doesn't go above 4k-6k. One of the reasons is that this is about the last stop (generally) for being able to repair damage and still finish with a very good quality edge. Is also in use about all one could need for any ordinary task and in my opinion will outperform a finer edge in use and longevity when used for EDU. Often I stop at approx 600-800 grit (about 1k-1200 Japanese) for daily use. If I have to beat up the edge on a given task, I can still generally bring it right back on the one stone and still shave arm hair and crosscut newsprint. Some tasks benefit from the edge being taken up another notch in refinement (more carving, shaving, chopping) and if so, I'll go ahead and do it. A sharp edge is a consumable resource, I don't romanticize it - I'm not doing more than is needed just because I can.

I generally determine edge condition by how it cuts, or based on what I've been using it for. I have come up with no easier metric than what I learned from a Murray Carter tutorial, IIRC "three finger sticky and shaves arm hair, edge is considered sharp". I might want it better when its right off the stone etc, but in use I won't touch it up if it still has those qualities. Most of the time, a three finger test is all that's needed. If its a chopping edge on a machete, hatchet, or Chef's knife, I want it to pile hair up on the blade, no popping. Should still be sticky. Again, if it does its job well, I might not even bother to inspect it closely.

 

[Chignecto Woodsman]

A lot of the compounds have very inconsistent grit, they can be twice as rough as the stated grit. And you have to keep in mind that you are pulling with the knife and tearing steel off.

I would agree with HeavyHanded, you probably want to use what gives you a workable edge. And that is a mix of stones, compound, steels, and stropping. The steel will quickly realign your edge, but the weak material will not last long and becomes prone to chipping out. I would say steel two or three times at most after skinning or carving. Then go back to the steel. Probably about the same with compound, maybe 3-4 times with compound and then fix the edge with a fine stone.