There is a lot of mystery surrounding how to sharpen serrated knives. I know that serrated knives would enjoy more popularity if people understood how to sharpen them as universally as plain edges.
This topic will serve as a simple, up to date list of tips for sharpening your serrated knives.
I will constantly be updating this first post, so that you won't have to read through the entire thread to absorb all the advice. In addition to a text list, there will be tutorial videos at the end of the post.
July 2020 update
to see a quick two minute video on how I sharpen my serrated knives.
Tips For Sharpening Serrated Knives
1. Clean your rods
. Clean stones are important to achieve the best edge. With serrated knives this is even more true, because the small contact area on your stones mean they get clogged extremely fast. I use barkeepers friend and a scouring pad between sharpening sessions, and I keep a wet rag with me while I sharpen. I wipe the rods down once a minute, or rotate to a fresh corner. Any time you can see bits of metal on the corners of your rods, they are giving you less than optimal performance.
2. Use one pass across the entire edge
rather than sharpening individual serrations. The latter is a waste of time, taking exponentially longer to produce an edge that's no better than using one smooth swipe like a plain edge knife.
3. Be very careful not to drag your tip off the corner of the sharpmaker stones
. Stop just shy of the tip. Once you're happy with the edge, you can switch to the flats of the stones and work on the plain edge portion at the tip. Otherwise you'll quickly round it off and decrease the functionality of your knife.
4. The wide bevel acts as a built in angle guide.
On Spydercos serrated knives, the bevel on the presentation side is very wide. What this enables you to do is rock the knife back and forth on your stone and use tactile feedback to feel for the right angle. You can feel the edge click into place when its held at the right angle.
5. Try using alternating passes when you sharpen, with some strokes going heel to tip, and others going tip to heal. The theory is when you do this it makes it easier to hit the entire serration on both sides. (I do not use this method, but others have success with it.)
6. Use edge leading strokes.
This minimizes bur formation.
7. Your serrated knife is chisel ground, which requires a different technique than a V grind.
When I am grinding the back bevel, reprofiling a SE knife, or repairing heavy damage, I do nearly all my grinding on the presentation side rather than grinding both sides evenly like a plain edge knife. When I am doing typical sharpening strokes, I do around a 6:1 ratio, doing six strokes on the presentation side, then one shallow, light stroke on the back. When finishing the edge, I use a 2:1 ratio.
8. When peforming your deburring strokes on the back side, use a very shallow angle.
Lay the back side flat to the stone, then tilt it up a few degrees. This helps maintain a thinner apex, which is where serrated edges get a lot of their impressive cutting ability from. Bear in mind any stroke you do on the back side is simply to debur. There is no reason to grind away at the back side.
9. Nearly all the serrated Spydercos I own came ground at 15 degrees per side.
I have only seen one ground at 20 degrees, and none ground more obtuse than that.
10. You can sharpen at 15 degrees or 20 degrees,
either angle works for knives ground at 15 degrees. Sharpening at 15 degrees takes a bit more time but provides superior cutting ability. Sharpening at 20 degrees is faster, gives you a stronger edge, but reduces cutting ability a bit. I sharpen the majority of mine at 15 degrees, with rough use knives / beaters getting a 20 degree edge.
11. If you sharpen at 20 degrees, I highly recommend grinding at 15 degrees with diamond / cbn rods periodically to maintain a thinner edge.
You do not need to grind all the way to the apex. You just need to grind enough to thin the blade out behind the edge bevel. This will maintain the same level of performance over time rather than letting it drop as the edge thickens.
12. UNLIKE sharpening plain edged knives, you DO NOT follow the curve of the blade.
Doing so will prevent you from hitting the length of the edge, because the angle of the stone will not match the angle of the serrations, and it won't get in between the ridges. Compare a serrated hawkbill, wharncliffe and drop point. Hold them side by side and look at the direction the serrations are ground. You'll see every serration is ground parallel to the last, meaning they all face exactly the same direction. The stroke you'll use to sharpen a hawkbill, therefore, is the same as the stroke you'll use to sharpen a drop point or a wharncliffe.
13. Always finish with a light touch.
As a general rule of thumb when using the sharpmaker, you should be able to do your finishing strokes without moving the sharpmaker base at all, without securing it with your off hand, a clamp, etc. If it moves, you're pushing too hard. This is true for PE and SE, any blade shape, any steel, any grit rods. This ensures a crisper apex.
14. Serrated edges can be stropped.
I use a typical strop, thin hard leather glued to a wooden block. To strop my SE knives, I liberally rub green buffing compound on the corner of my strop, then use that corner like a sharpmaker rod, except I use edge trailing strokes. I have heard of others using a leather boot lace under tension to strop SE. The serrated H1 knife I carry responds really well to a strop, so does the 420HC on my serrated Leatherman blades.
15. Some users here have reported excellent results from stropping with a dremel.
I have not tried this myself, but the basic idea is to use a buffing wheel loaded with compound, set the dremel to the lowest setting, then use it to buff the edge in a way that the wheel spins away from the cutting edge.
If you prefer video format, this will show you most of what I discussed above. Bear in mind I was going a little quick and sloppy in the video compared to how I really sharpen.
I'll be making a better video for this thread sometime this year. The info is alright but the presentation is awful.