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View Full Version : Changing bevels? Is it bad for the steel?



jgraeff
12-09-2011, 02:28 PM
If you want to experiment with different bevels on a knife is that bad or will it shorten the knifes life?

I have considered lowering my bevel to see if it will still hold the edge, although if it doesn't and i want to restore the other bevel is this difficult to do or is it bad to do this?

JBroida
12-09-2011, 02:35 PM
i recommend working slowly in this... what i mean is dont make drastic changes. Lower just a bit each time until the edge doesnt hold up anymore, then back off a bit. You shouldnt cause too much damage. However, you are removing steel, so that can not be put back on. In general, you're not likely to cause a lot of damage if you take your time and make changes slowly, but, as with anything, there is always a risk. If you do thin too much, you can always convex or use a microbevel to increase edge strength though.

tk59
12-09-2011, 11:47 PM
I generally go immediately to a 90/10 or so and down to 10-ish deg on the right and 15-ish on the left on my own general purpose knives. Pretty much any good steel is going to hold this just fine for any but the most abusive users. Then, I basically do as Jon described. That way, I get to where I want to go a lot faster. Most stock edges come with uneven bevels or ground at fairly high angles anyway. No sense in really keeping those.

jgraeff
12-10-2011, 12:00 AM
Well i lowered them just a bit while i was bored at work today. Went down to about 12-15ish degrees on both sides. although as much as i tried right on the hell of the right side it is steeper angle. Almost at what it was at originally but a little shallower. I tried going over it making sure i was at the same angle as the rest of the blade, and wasn't wobbling too much. Not sure when i can't get it even with the rest of the edge.

Two other mistakes or possible mistakes. On the back of the blade, the middle of the edge has an indent in it i guess i could describe it, i think i possibly wobbled too much in that spot? doesn't seem to affect it too much so I'm going to leave it alone until next time.

Also on the front side of the blade, when i look at it straight on i can't see the edge, i have to turn it up a bit and then i can see it not sure if I'm explaining this to where you guys can understand. Im just curious if this is what a convex grind is supposed to look like or if I'm just thinking it looks weird?

I went with a 60/40 didn't want to change too much at first since I'm still learning about these things.

also noticeably sharper for sure and seems to be pretty durable, must have chopped about 6qts of herbs today right after sharpening and still was sharper than what i have been getting it lately.

tk59
12-10-2011, 02:59 AM
What knife are we talking about?

jgraeff
12-10-2011, 09:45 AM
Oh sorry Konosuke HD gyuto

tk59
12-10-2011, 10:53 AM
I've thinned mine down to somewhere between 20 and 25 deg total.

jgraeff
12-12-2011, 05:40 PM
Oh really do you think that 15 is too low for the konosuke?

I have noticed a micro chip in the tip not sure if it's lack of sharpening skill, the steel failing, or if it's from a pear stem as I cut lots of these.

Andrew H
12-12-2011, 05:43 PM
Tinh is counting both sides when he says "20-25 deg total."

tk59
12-12-2011, 06:18 PM
Tinh is counting both sides when he says "20-25 deg total."Right. The front side is 10 ish deg max. and the back is 15 deg max. I'm estimating. Don't shoot me if someone measures it and it turns out to be 12 and 18 but I would be surprised though. The front side is pretty damn low and the bevel is pretty large although it's been convexed...

jgraeff
12-12-2011, 11:53 PM
Ah i understand now i was a bit confused at first. But ya i do have a small chip in the front not sure what caused it however i might raise it just slightly. As i have not needed a microbevel on the knife yet.

This whole sharpening thing really require a lot of knowledge i wish there were more classes or skilled people around to learn from.

Benuser
12-13-2011, 01:02 AM
A single chip is no reason to change geometry. Try to keep with the same before changing anything, and then, just alter by small steps as previously suggested.

memorael
12-13-2011, 03:41 AM
to get rid of the chip I would suggest you do about a 45 degree full swipe sharpening with the same pressure all over the edge to avoid changing the geometry of the knife and then thin and sharpen the knife back to whatever it is you want it to be. I wouldn't say changing the bevels is a huge deal but doing it properly is another deal. As suggested go slow I messed up a couple of knives by doing things really quick without knowing exactly what was going on (my ignoranus days). Anyway just make sure you don't put to much pressure at a very low angle creating a foil edge which will mess up your knife really bad.