Buck 110 – 2 dot advice…

Hi Robert,

A 20/20 edge on your buck sounds fine to me. Give it a start from there. You can also increase the angles from there. You’ll just need to take some time to restore the edge if it was ruined. Don’t know what that means, but if it means microchips and so on, please take your time to work those out. I guess you’ll spend quite some time on you 100/200 stones or (if it’s really bad) the 50/80’s.

440C should not be a particularly hard job, since it’s not a particularly hard steel. Just make sure your angles are not too low. (As said, start with 20 degrees, but if that’s too low, increase it to 25 or so.)

Success! And please keep us posted on you experiences!

I too have a Buck 110 from about the same era. If its not 440C, it’s something close to it.

Mark’s point about microchips and dings is particularly important when referring to a knife that’s had a lot of hard miles. Check your edge with a jeweler’s loupe to identify the worst points of damage. I think this is an ideal place to use RazorEdge’s method of flattening the edge with a stone (maybe 400g) held at a right angle. Stone the edge flat until the worst chip or ding is completely removed or at least removed from the vicinity of what will be your new apex.

Now that the damage is removed, use your coarse stones at your selected angle (20?) to rapidly return the edge bevels. When you get close to creating the new apex, switch to your 400’s to remove the deepest scratches and toform the apex. Then switch to 600’s to finish the edge. You can go higher if you have the stones at hand, but I wouldn’t go higher than 1000.

The reasons for flattening the edge are two-fold. First, it greatly reduces the amount of stoning required. Stoning effort is a function of grit and square inches of stone passing over square inches of steel. With the top of the edge gone, a typical bevel might be reduced by as much as 10%. Second, it nearly eliminates the chance of stoning with coarse stones at the apex, where they might produce severe chipping. Done properly, the apex will only see grits of 400 or more, none of which produce chipping. A chip caused by a too-coarse grit is just as damaging as chips produced by daily tasks.

I’ve watched that “destressing” video a couple of times and I’m still not a big believer in the theory. Nearly all metals have internal stresses created by the forming process. Machining removes material from one side or another of these stress lines, thus lending the part to dimensional deformation. This principle is also seen in wood. Run a plank through a planer enough and it might suddenly warp on you. Nature doesn’t grow trees perfectly straight. Here, the planer has removed the material which was keeping it straight.

From my experience, there are two kinds of fractures seen along edges – those parallel to the long axis of the blade and those perpendicular to the blade. The first, I believe, is inherent in the steel and caused by pressure applied to an area of incomplete crystallization. Here’s an example of the type I’m talking about:

The second type of fracture is caused by thermal stresses created during the heat treatment process. I had this happen to me once when I tried to air-harden an inexpensive Sheffield blade. During the cool-down, I heard a loud “clink!” and was saddened to see the edge had cracked through, with the crack extending about a half-inch up into the meat of the blade. These fractures are caused by an excess of non-uniform cooling occurring in the steel. Basically, the edge, being thinner that the rest of the blade, cools faster. Since metal expands and contracts with temperature changes, the thin edge contracts faster than the bulk of the blade. This can create stresses in the tens of thousand of pounds. If the stress exceeds the tensile strength of the steel, it simply parts. Here’s a photo of an example. Some of you might remember my bout with the IKEA Damascus blade. The core material shrank faster than the material it was wrapped in.

Large pieces of metal which is going to be heavily machined are typically put through a process called “stress relieving.” Basically, you’d heat the metal to within 75 C of its hardening temp (correction: “transformation temp”…about 1300F), let it soak through and then let it cool in still air. This is a form of annealing, whereby the metal is held at a temp which allows for grain orientation to occur. I don’t think that’s happening here, either by improper sharpening at the factory or by flattening the edge.

If there is really something going on with this “destressing” process which changes the properties of the steel. I’d like to see the science behind it. Don’t take this as some sarcastic swipe. I believe those who say it works in saving a blade which will not sharpen and I genuinely would like to understand it.

Destressing or not, the benefits of flattening the edge are real.

A couple of minor edits 9/8/14 4:20PM CST