Reply To: micro bevel to eliminate tear-out -Spyderco Paramilitary CPM-S110V
Henry, I believe you have a couple issues going on there…
First, like you said, the diamond stones may not be fully broken-in yet. I think you’ll continue to see further improvement in the resulting scratch patterns with continued use.
Then it appears your technique may need more practice and ultimate improvement. Although it’s a little difficult to follow the submitted photos, as the magnification is not the same ‘high power” for all of these, it appears that your stonework may not be apexing the bevel with every grit you used. Some photos it appears your right where you need to be and others it appears you’re not reaching the apex. Some photos I see a clear burr in place while others it’s not there. (I know there are a lot of factors involved like when and where the photo was taken that may be misleading me).
As “tcmeyer” sometimes points out, there is a slight difference in the diamond stone thicknesses as the grits become finer and finer. Because of this, I’ve learned to double check my set angles and make micro-angle adjustments with each and every grit I use. Working with the precise angles the W.E. allows us to utilize, the angle cubes allow us to adjust for and the visual results of our adjustments the USB scopes allow us to see, it requires a higher degree of attention to detail, on our part, to make use of this precision.
It’s also important to employ the same finger hold position with each and every grit. Depending on how and where you place your fingertips on the stone paddle can affect where the scratch pattern is applied to the knife edge. So, consistency is key.
Don’t fall in the trap looking for something wrong, like steel hardness, to blame or explain unacceptable sharpening results on. Steel hardness is a contributor to our sharpening difficulties. That’s why I employ different sharpening mediums that I have found to be better suited for the steels I’m sharpening. I believe Spyderco does apply a heat-treatment to their steels resulting in a slightly harder HRc rating then others may utilize. This harder steel seems to have a greater tendency to be chip prone when sharpening it. Also, realize you’re inspecting your edges under magnification, so the chips and sharpening defects are not really as bad as they appear they are. What some may call edge “tear out” is simply the normal grit’s scratch pattern following off the apex. I’m not saying the diamond stones can and will give you the results you seek with the CPM-S110V. Just not to jump to conclusions yet. Keep working on your technique and using those stones more.
I, like tcmeyer, also utilize an alternate side, left-right-left-right, edge leading sharpening stroke. For me it’s the final stroke direction with each and every grit. This removes any resulting burrs and wire edges that were applied with edge trailing strokes.
I will finish by saying, look into the technique for applying micro-bevels and the purpose(s) for using them. Of course, it’s your knife, so you’re welcome to it anyway you like.
Marc
(MarcH's Rack-Its)
