Sharpening Various Types of Serrated Edges

[Bret Koesser]

I'm always looking for a better way and in this case it's about sharpening serrated/scalloped knives. Currently I don't have a machine capable of running a wheel. I do have a belt sander in the form of a Ken Onion Elite as well has some manual abrasives like DMT diamond cones, Spyderco ceramic triangle rods as well as other ceramic rods.

While a bit more tedious than I'd like, it's easy to deal with scalloped edges. However, looking at some other patterns of serrations it seems less straightforward than find a size to fit the bottom of a scallop and raise a burr and then deburr. There are reverse scallops and a pattern like this picture...

The knife on the left has me wondering what the best way to sharpen it (when it's needed, currently a long way from needing to be sharpened). I just want to have a plan and I'm not going to practice on this one.

Maybe someone has an old serrated knife they want to get rid of for cheap? I'm going to look local for some "trash" serrated knives to experiment on.

Anyway, I was hoping to discuss...

 

[HumbleHomeCook]

With serrated, my method is to basically approach each serration as a separate blade. I raise a burr on the inside of the scallop and then deburr the "flat" side on a bench stone. There's just so much you're going to do but I've found it's usually enough.

Tapered diamond rods and round Arkansas stone "files" can be effective. You can use sandpaper around a small dowel. I've even read of people using coarse Scotch Brite but I wouldn't do that on anything you like the look of. The same with small brass wire wheels in a drill.

That knife on the left with the full wave would have me searching the net for laser sharpening.

 

[Bret Koesser]

@HumbleHomeCook you didn't mention how/what you're doing to raise the burr from the front of the scallop.

 

[HumbleHomeCook]

@HumbleHomeCook you didn't mention how/what you're doing to raise the burr from the front of the scallop.

Sorry I should've been more specific. The tapered diamond rod I mentioned and sandpaper around a small dowel have worked for me inside the scallop.

 

[cotedupy]

I tend to do what HHC said above; a tapered slipstone of some kind, or sandpaper around a chopstick (even better than a dowel, cos chopsticks have some taper to them).

Though if you want to really speed things up... a colleague of mine does it with a diamond coated dremel attachment.

 

[Bret Koesser]

I need this Steelport machine.

Steelport serrated maker

 

[mike59]

In the leather crafting world there is a beast called an edge beveler - basically a knife to round the edge of a piece of leather. Very sharp and needs to be. When it starts to dull you can use any variety of methods as mentioned above but there is a cheap cool thingy that you lay sandpaper over and go to it. They have multiple sizes of ridges for the different size edge bevelers so easier in my opinion than trying to find the right sized thing (chop sticks, dowels, ... etc) for any given scallop size - Google search for "edge beveler sharpener" and many will turn up and most any of them would work well for a variety of serrated/scalloped edges.

I'm sure there are many videos out there also showing how to use one but it's pretty much common sense.

Hope this helps or perhaps spurs another idea if nothing else.

 

[NJDan]

In the leather crafting world there is a beast called an edge beveler - basically a knife to round the edge of a piece of leather. Very sharp and needs to be. When it starts to dull you can use any variety of methods as mentioned above but there is a cheap cool thingy that you lay sandpaper over and go to it. They have multiple sizes of ridges for the different size edge bevelers so easier in my opinion than trying to find the right sized thing (chop sticks, dowels, ... etc) for any given scallop size - Google search for "edge beveler sharpener" and many will turn up and most any of them would work well for a variety of serrated/scalloped edges.

I'm sure there are many videos out there also showing how to use one but it's pretty much common sense.

Hope this helps or perhaps spurs another idea if nothing else.

Do you mean this? I'm not sure how that would work for a knife. It seems the other ridges would get in the way. I'm also looking for a good way to sharpen my serrated knives. Is it possible to find a diamond dowel-type steel the correct diameter or is finding a beveled one the best you can hope for?

https://encrypted-tbn2.gstatic.com/...5PnQa-xhIfRlAiPeQDDSjKuT2X8l3U5dVpFz91gIdy0WY

 

[Desert Rat]

I do ok on stone corners for a touch up with rounded teeth but will sometimes use sandpaper folded and shaped like a gouge stone for the rounded top of the teeth.

I think the top of the teeth do more work than the gullets so that is my main focus.

 

[NJDan]

I do ok on stone corners for a touch up with rounded teeth but will sometimes use sandpaper folded and shaped like a gouge stone for the rounded top of the teeth.

I think the top of the teeth do more work than the gullets so that is my main focus.

I'm surprised there isn't a tool specifically made for serrated knives. Everyone seems to have their own way of doing it.

Thanks!

 

[mike59]

Do you mean this? I'm not sure how that would work for a knife. It seems the other ridges would get in the way. I'm also looking for a good way to sharpen my serrated knives. Is it possible to find a diamond dowel-type steel the correct diameter or is finding a beveled one the best you can hope for?

https://encrypted-tbn2.gstatic.com/...5PnQa-xhIfRlAiPeQDDSjKuT2X8l3U5dVpFz91gIdy0WY

Ouch ... yes, that's what I'm talking about and yes - I think you are correct that the others ridges would get in the way now that I think about it

I know that most of them are plastic so I guess you could shave/grind others out of the way but that seems like overkill. Maybe this will spur a similar thought.

Good catch and sorry for the not so well thought out idea.

 

[M1k3]

I'm surprised there isn't a tool specifically made for serrated knives. Everyone seems to have their own way of doing it.

Thanks!

There is, but they are powered and kind of expensive.

 

[NJDan]

I don't mean to be hijacking a thread but this seems to be a good place to discuss serrated sharpening. I couldn't find my emery cloth so I wrapped some 400 grit sandpaper around a pen and used it to sharpen the knife. I went 10 times back and forth in each serration. This improved the knife significantly. If I follow that with something like 800 or 1000 grit will that improve performance more?

 

[Bret Koesser]

It's debatable just how much cutting performance would improve. I would expect a little, but likely not as much as your first run with the 400 grit.

I would say give it a shot and see if you can tell a noticeable difference and that would be your answer. My go to approach is 600 grit equivalent diamond cone, so you're right about in that range. It works well with symmetrical scallops but I don't know how to deal with the wave pattern serrations. You should be fine either way staying with a 400 grit finish or refining with 800 grit.

 

[Benuser]

I don't mean to be hijacking a thread but this seems to be a good place to discuss serrated sharpening. I couldn't find my emery cloth so I wrapped some 400 grit sandpaper around a pen and used it to sharpen the knife. I went 10 times back and forth in each serration. This improved the knife significantly. If I follow that with something like 800 or 1000 grit will that improve performance more?

With sharpening a plain edge, a finer grit is chosen only if the burr doesn't get any smaller when flipping between sides. As long as it gets smaller you stay with the given grit. This is a purely theoretical approach: haven't yet tried myself to follow a progression with serrations. Most serrated blades are made of soft stainless where looking for any refinement were vain.

 

[Skylar303]

I don't use serrated knives much, had an old cutco serrated that cutno... probably not the Best option but what I had on hand which was a file. A few swipes in each serration would raise a burr then just deburred the backside. Seems okay. Not as ugly with the scratches as I'd expected with a file. I assume they're clean-ish looking bc the file fit well and could take the whole bit of metal out at once essentially.

 

[NJDan]

With sharpening a plain edge, a finer grit is chosen only if the burr doesn't get any smaller when flipping between sides. As long as it gets smaller you stay with the given grit. This is a purely theoretical approach: haven't yet tried myself to follow a progression with serrations. Most serrated blades are made of soft stainless where looking for any refinement were vain.

I'll give it a try and report back.