Grinding toward or away...? And Happy New Year!!!

[Justin]

First off Happy new year people!

I was thinking about different tools and there sharpening needs. It seems some require (or are advised) to be ground with either the wheel travelling toward or away from the tool.

1- Is there a reason some tools are ground one way ore the other, single bevel, double bevel etc..?

2- Is there pros/cons to grind direction?

I am personally concerned about kitchen knives but also curious in all edges.

Cheers, Justin

[Jeff Farris]

In general....

Grinding with the wheel turning into the edge will cut faster and leave less of a burr.

Grinding with the wheel turning away from the edge cuts slower, allows you better control of the cut, but in certain steels leaves a more pronounced burr.

Or to put it briefer...

Turning in - faster
Turning away - better control

I do all freehand sharpening with the wheel turning away from the edge. Chisels, plane irons and other straight edges that generally need a serious amount of material removed I do with the wheel turning into the edge.

Another issue is grindstone wear. Tools with a small contact area -- like gouges -- dig into the grindstone when it is turning into the edge. They're less damaging when the wheel is turning away from the edge. Therefore, I do almost all turning tools and carving tools with the wheel turning away from the edge.

In the back of the handbook, there is a chart that shows the recommended approach for each tool.

[Ken S]

Good question, Justin.

Good answer, Jeff.

Good was to start the New Year.

Ken

[Justin]

Cheers Jeff,
So i take it there is no difference in the edge quality?

[Jeff Farris]

Not after you remove the wire edge (burr) on the honing wheel. There's no difference between edge quality, only the time it takes to get there and wear on the grindstone.

[Justin]

Thanks!

[Rob]

Happy new year all. Just to add to the debate re knives, I was lucky enough to get a set of Global knives at Christmas.  Boy....what an edge....I can slice tomatoes with just the weight of the knife and they're seriously light and well balanced.  I was a little worried about grinding them as I didn't want to cock it up given the staggering price tag they carry.  The edge has definitely lasted longer than an el cheapo but eventually I bit the bullet and fired up the big T. I decided to try a 15 degree bevel given the quality of the steel and very carefully ground the first side after dressing the stone (and grading to 1000 grit).  It left a superbly well defined and uniform bevel.  Just to monitor progress mid grind so to speak, I tested the edge without grinding the other side or honing......it sliced through paper like.....a very sharp knife indeed!  So I left it, on the assumption of if it ain't broke don't fix it. I guess, completing the process would have the edge last longer, but I'm now two weeks on with a truck load of chopped veg behind me. I think the chap who mentioned knives becoming part of ones estate hit the nail on the head for me.  Rather like Lie Nielsen and the heirloom quality strap line, I just know these knives will go the distance. In an all too throw away consumer culture, I find that rather reassuring somehow.

[Justin]

15 is the correct factory angle for Global. Did you use any jigs or just freehand, grinding away or toward?

[Rob]

Hi Justin

Ordinarily I grind kitchen knives freehand, on this occasion I used the short knife jig just to be certain I had as much control as possible.  (Again out of respect for the cost of global knives) I ground in the upright position ie towards the edge which is the more aggressive position. However as I mentioned in my previous, I had dressed and 1000 gritted the stone so it was as "gentle" as it could be. I also go really easy on the hand pressure and it just slices uniformly over the stone. I use Jeff's video tips and watch the water "wave" on the bevel to tell me if I've got the raising angle correct as I approach the curved tip of the knife. That part was always hair raising when I first bought the Tormek. It's a really useful tip and works every time.

Ironically, having digested these threads, with hindsight, I will try away fon the edge next time given its an even more controlled method. I'm just used to doing knives in the upright position and I guess I was trying to minimise variables that might cause problems. I grind all my turning tools away from the edge, surprised I didn't think of it in fact. I guess that's the beauty of these discussions :-)