Need some advice for chef's knife sharpening

[Mojoman]

Ive only owned my Tormek T-4 for a few months now, but Im having issues with gouges in the stone. Let's start by also saying I keep my knives sharp so i only have to polish a little on my SJ-200 stone and strop.  I bought a set of digital calipers and using an angle calculator to find the angle of my edges. After setting the correct angle with the WM-200 angle guide, I have been sharpening against the grain of the wheel. I keep the edge flat when drawing across the stone but three times now for whatever reason, I the blade has caught the stone and gouged a chip in the wheel. I have to flatten the wheel until the chip has gone away. At $332 I cant afford to wreck the stone like that. To combat this I have been free hand sharpening with the grain the wheel instead of against and eyeballing the angle. I have been getting razor sharp results. So a couple questions I have are 1- Any ideas what am I doing wrong to gouge the stone? 2- Can you use the knife jig when sharpening with the grain or is that just for wood tools? Id love any advice anyone can give. Thanks.

[John_B]

When you are sharpening with the stone rotating towards you it is easy to nick it when you reach either end of the knife if you are not careful. I would only use the Japanese stone rotating away from you. I never much liked the WM-200 for setting an angle but it does work on the wheel rotating towards or away from you. I also found that guided honing dramatically shortens the learning curve and gives better results for most sharpeners.

I like the new KS-123 Knife Angle Setter or you could use the free spreadsheet app to accurately set your sharpening angle. Look here for links to apps. https://www.sharpeninghandbook.info/indexCalc.html.

I would also watch videos on the Tormek YouTube channel.

[Ken S]

Welcome to the forum, Mojoman. 

Try using your stone grader to knock the sharp corners off of your SJ-200.This is good practice and also applies to your SG-200. (Do not do this with diamond wheels!!!)

Keep us posted.

Ken

[tgbto]

Hello @Mojoman,

First of all, the nicks in the stone have nothing to do with how you set the angle. The WM-200 is a dodgy solution for setting knife angles, and if you want to "just polish", then a sharpie is a much more efficient tool, but that's beyond the point.

I think your issues come from a few things :
- You may not be holding the knife jig against the USB firmly enough. So whenever the knife starts moving a bit with the rotation of the stone, you enter the domain of static friction between the blade and stone. Then things go quickly amiss from here : the knife will move up quickly, the angle will increase quickly, and then whenever the knife is stopped again; either by your hand or by the USB or whatever, it will dig into the stone at a high angle. Had you been using the SG stone, you'd just have ruined a tiny portion of the knife edge, but not the stone. With the SJ, the stone yields first. The remedy to this is to build more experience with the SG before using the SJ stone heavily. You mentioned needing only to sharpen a little on the SJ and then strop, have you tried sharpening a little on the SG then stropping, to see if the edge is satisfactory ? Or even just honing on the leather wheel ?
- Polishing edge trailing (with the stone rotating away from the edge) avoids this issue, but creates others : a foil-like burr, slower grinding, MB-102 or FVB mandatory for controlled-angle grinding,...
- Sharp shoulders on the stone, as mentioned by Ken. However those will tend to create nicks on the shoulders themselves when laying down the knife. Rounding them out is good practice for all stones, and especially on the soft SJ to avoid chipping it when truing it.

I have a rather complex history with the SJ stone : I have been using it a lot at first, as I ordered it along with my T8, probably because I was used to sharpening with high-grit japanese benchstones. And I've been nicking it quite a bit then. Then as I got rid of the rookie mistakes such as not holding the jig properly, I also got rid of the nicks. But careful experiment showed that the assertion by Tormek that the SJ eliminated the need for honing was incorrect : the burr may not be apparent, but a tiny bit of plastified metal sits at the Apex, and it needs to be removed with about as much honing as a SG-generated burr. Also, honing with the PA-70 compound after a few light passes on the SG leaves such a good finish that I haven't felt the need for SJ-based polishing on most knives. So now I use it only occasionally, on very specific high-hardness knives where looks are somehow more important than actual edge retention in the kitchen.

And you may want to take a good look at the MB-102. It is one of those Tormek pieces of hardware that I feel should be part of a knife-sharpening kit, or a T4/8 knife sharpening edition, as they greatly increase sharpening efficiency. If you often reset angles, the KS-123 is a good tool as well.

Cheers !