I have a quick question for Donovan, I know you said you use polished edges, what grit do you finish with? On my M4 knives (both small fixed blades at 62-63 RC) they get extremely sharp and take a very fine edge all the way out to .05 microns, and they perform extremely good. At .05 microns there ain't much in the way of teeth though, and I doubt you use an abrasive that fine.
One last question would be what is the worst edge damage you've seen on your competition knife, and how did it happen? I'd imagine practice allows you to hit very square on your cuts, where if I were chopping that 2x4 I bet I would hit it a bit off center and get some damage on that very thin edge. Lateral loading is the enemy of knife edges everywhere, especially thin ones, so is it mostly practice that allows you to get so little damage on the knives, or is the steel good enough to hold up to an off center chop?
Thanks, Mike
Very good questions, Mike.
What I meant by "still has some teeth" is I find that M4 will slice better than some steels I have used with the same sharpening sequence as below.
What I do is start with a 60 micron belt which is about the same as the 400 grit to set the initial edge, the reason I use the 60 micron is because the edges of the belt don't roll as bad. Then I go to a 30 micron belt, then 800 grit cork belt loaded with green chrome rouge, then leather strop loaded with green chrome rouge. The 8K grit diamond paste on the leather strop I used at the last comp really has my attention. Need to get some and experiment some more.
On my knives, I have wrinkled a couple. It was not bad enough that I could not get it out then resharpen. But I had a lot of help from guys who had wrecked a lot knives when I started. Now I just want to clarify that some of the other guys grind theirs thinner than I do. I leave more meat on mine because I hit harder than some guys. The wrinkles I got in mine taught me how far I could push it. When I say thinner I am referring to the primary bevel being thinner not the secondary.
I have seen others knives damaged though. In one cut we were cutting empty shotgun shells from the side. The goal was to cut off only plastic at a angle. One guy hit it too low and hit the primer pocket, it chipped the edge bad enough he was disqualified. That in my opinion is to be expected. Another guy was chopping a vertical 2X4 with a knife that had just been finished, he had not tested the knife and was a new cutter. He chipped out a pretty good section of the blade. Whether it chipped out because of user or maker I cannot say. Another cutter was using a borrowed knife that was ground thinner than he was used to. He hit the hardwood dowel at an angle and put a severe (IMHO) wrinkle in the edge. He is an experienced cutter and makes his own knives, he just decided to borrow another maker's knife to try it out. It was evident what had put the wrinkle there, it was almost the same length as the circumference of the dowel and stuck out almost 1/4" from the rest of the edge. But the steel did not crack. This is just a few examples. We push the steel hard.
One of the tests I do on a new comp knife is to chop straight down on the edge of a 2x4 as hard as I can. When chopping straight down you put more force on the edge. After I am worn out from that and have verified the edge held up with no wrinkles or chips, I then find the board with biggest, ugliest knot I can find and chop through it. If the edge survives this then I cut 2X4's in the normal manner (angle cuts) until I am satisfied that the edge is strong enough. I have also cut hardwood boards, landscaping timbers, hardwood fence posts, just whatever I can find to punish the blade until I am confident in the blade. The reason I chop as much as I can is because the more tired you become the sloppier with technique you get. So if I have cut enough to be tired then my technique is not as good as it was when I first started, therefore my wrist is rolling more and that kind of thing. Hope this answers your questions.
