Do i have a heat treat issue?

[Evil D]

My regular routine for checking for a burr is by running my thumb down along the side of the edge of the knife, and that has proven to be pretty reliable thus far. It's easy to feel even the slightest burr this way but i'm really interested in trying out the loupe. I haven't had a chance to do anything with it since posting this. Holding the edge under a 100w lamp shows no shiny spots anywhere on the edge.

I'll tell ya one thing...not being able to sharpen a knife you just bought and fell in love with sure does put a damper on things

[Donut]

David, the failsafe way of checking if there is a burr is to strop it. If you don't have a strop, look up cardboard stropping. If the problem is a burr, I am in the high 90's percent sure stropping will fix it.

Honestly, I think stropping will fix a really large percent of sharpening errors.

[Evil D]

Well i stropped it on a piece of card stock and it's definitely sharper, but still not as sharp as my Cento 4.

Perhaps i'm seeing the difference in VG10 and S30V for the first time? People always rave about VG10 and its ability to get a hair whittling edge. I don't know if i've ever really spent enough quality time going back and forth between the two to see any difference...until now? I've been carrying S30V for over a year pretty much exclusively until recently i carried the Cento 4 for a couple weeks.

[seanv]

I actually started stropping my blades on a legal pad backer; that weird cardboard stock stuff they place behind that last sheet. Works great for me.

[chuck_roxas45]

I like the cardboard of those cereal boxes myself.

[sal]

Hi Evil D,

It's also possible that you are very sensitive to the edge and what you're feeling is the thickness difference which creates an angle difference of the bevel grind. Or as you mention, the difference in steels. Remember; "getting very sharp" and "staying sharp for a long time" are two different properties.

sal

[phillipsted]

I found a good deal on a USB handheld microscope on line. It is called the Orion MicroExplore and you can pick it up for under $50, which includes software for your PC. There are other good ones made by the company Dino-Lite.

These are really good for inspecting the edge of your knive when you are sharpening it. I always worry that I'm getting a bit to close to the edge with my jeweler's loupe. :eek:

The digital scope allow you to see the edge right on your screen - and can magnify up to 100x - more than a loupe. The PC software can also snap photos and make movies to share. Well worth the cost. Plus the kids can use it for science experiments once they've pried it out of my hands...

TedP

[MountainManJim]

So, I guess I don't understand why heat treat would effect one's ability to get a knife sharp. It seems that my knives with softer steels can be sharpened to a higher level of sharpness then those that are are harder. The only issue I've seen with softer steels is a burr that won't go away. Can someone explain this?

I guess my sharpening tip is that it might be time to reprofile the edge, maybe to a lower than factory angle. For me, a poor or too large of a back angle is typically the cause of unsatisfactory sharpness of an edge. Just a thought.

Jim

[Evil D]

So, I guess I don't understand why heat treat would effect one's ability to get a knife sharp. It seems that my knives with softer steels can be sharpened to a higher level of sharpness then those that are are harder. The only issue I've seen with softer steels is a burr that won't go away. Can someone explain this?

Jim

I think you're right...i wasn't sure if this would be heat treat related or not but now that i think about it that shouldn't really effect the steel's ability to take the edge, but rather to hold it after being used.

[Cliff Stamp]

I don't know what it is, but i just can't seem to get my new Para 2 sharp enough.

What exactly is your sharpening procedure, and what steels has it worked well on?

So, I guess I don't understand why heat treat would effect one's ability to get a knife sharp.

There are many reasons why issues with the heat treatment could cause issues in sharpening. If the steel was under soaked then there could be very large aggregate primary carbides retained which are not stable in the very thin edge (sharpened edges are typically 0.5 microns wide) and thus they keep getting torn out by the hones. This can be resolved using diamond hones or polishing pastes which can cut high alloy carbides.

On the opposite side, if the steel is over soaked then the grain could suffer excessive growth and thus the again very thin edge will be weakened and prone to deformation and micro-chipping which will prevent a very high sharpness. This can be resolved by using ultra-light pressure, very clean hones and ideally very hard hones which cut with minimal pressure (i.e. diamonds, silicon/boron carbide abrasives).

[Donut]

I find that S30V is tougher to sharpen, maybe by 50% over VG-10. VG-10 is just easy to work with on a sharpener. If you do 20 strokes per side with VG-10, I would expect it to take 30 strokes per side with S30V.

I have seen the suggestion to work on one side until it feels like you rolled the edge. It will feel like the edge is gliding along the stone at that point, with less resistance. Then work on the other side until it feels like you rolled the edge.

At that point you can go back to the 20 or 30 per side.

[Evil D]

What exactly is your sharpening procedure, and what steels has it worked well on?

I start out with a fine diamond stone on a Lansky unless there are chips that need taken out. I use a marker and hit the bevel until i feel/see a burr on the opposite side all the way down the edge, then switch sides and repeat. After that i use a 650 grit Arkansas stone repeating the same thing per side, and then on to a 1000 grit (ceramic?) stone. By the time i'm done with the 1000 grit, i can't feel a burr on either side. I've just recently started stopping on a piece of cereal box cardboard which seemed to help a lot with VG10, but this is the first S30V i've done it with. This has worked with VG10, S30V, ZDP-189, 440c, SAK's, pretty much everything.

I find that S30V is tougher to sharpen, maybe by 50% over VG-10. VG-10 is just easy to work with on a sharpener. If you do 20 strokes per side with VG-10, I would expect it to take 30 strokes per side with S30V.

I have seen the suggestion to work on one side until it feels like you rolled the edge. It will feel like the edge is gliding along the stone at that point, with less resistance. Then work on the other side until it feels like you rolled the edge.

At that point you can go back to the 20 or 30 per side.

I've found it to take a little more work to reprofile, but nothing major. I always hit one side until i get a burr and then switch sides.

[Cliff Stamp]

I start out with a fine diamond stone on a Lansky unless there are chips that need taken out. I use a marker and hit the bevel until i feel/see a burr on the opposite side all the way down the edge, then switch sides and repeat. After that i use a 650 grit Arkansas stone repeating the same thing per side, and then on to a 1000 grit (ceramic?) stone. By the time i'm done with the 1000 grit, i can't feel a burr on either side. I've just recently started stopping on a piece of cereal box cardboard which seemed to help a lot with VG10, but this is the first S30V i've done it with. This has worked with VG10, S30V, ZDP-189, 440c, SAK's, pretty much everything.

A couple of points :

1) If stropping is doing anything it means the edge is not formed clean and there is a burr remaining. Stropping isn't the best way to remove this and will always produce a lower sharpness than an actual hone. I would recommend using Jeff Clark's burr removal technique.

2) Arkansas is a very soft abrasive, it is not going to cut well the highly alloyed carbide in S30V (vanadium carbide) so it would be expected to produce a lower sharpness in S30V than in other steels which lack the very hard carbides.

A question, how sharp is the edge right off of the fine diamond stone, can it shave, slice or push cut newsprint etc. ?

[sal]

Hi Cliff,

Glad to have you visit.

sal

[Evil D]

A couple of points :

1) If stropping is doing anything it means the edge is not formed clean and there is a burr remaining. Stropping isn't the best way to remove this and will always produce a lower sharpness than an actual hone. I would recommend using Jeff Clark's burr removal technique.

2) Arkansas is a very soft abrasive, it is not going to cut well the highly alloyed carbide in S30V (vanadium carbide) so it would be expected to produce a lower sharpness in S30V than in other steels which lack the very hard carbides.

A question, how sharp is the edge right off of the fine diamond stone, can it shave, slice or push cut newsprint etc. ?

I've never really tried because it ALWAYS leaves a burr, no matter what i do. It's fine, but course if you know what i mean. It's the finest diamond stone that Lansky makes, but i don't think it's fine enough to finish with.

I've always felt that the Arkansas stone wasn't course enough to follow the fine diamond with, but it hasn't seemed to hold me back in the past. It has enough cut to take out the scratches that the fine diamond stone leaves.

[seanv]

Good info., Cliff. I'm not too proud to admit I see two or three things I've done wrong in the past. Good information on technique here, all around.

[Cliff Stamp]

I've never really tried because it ALWAYS leaves a burr, no matter what i do.

That is the problem, this will be exaggerated on knives with a higher carbide volume and especially the ones with the higher vanadium content because those carbides are actually harder than most sharpening abrasives. You absolutely have to get rid of the burr before you move to finer stones, if you don't then it persists and what can happen is does get removed by the finer stones it can leave patches of the edge where it cracked off which are much rougher than the finer abrasive.

1) The simplest way is to take a piece of fairly abrasive wood and do a simple draw cut across the grain, usually 1-3 strokes is enough to remove the burr as you are just scraping it off. This will dull the edge slightly but not so much that the finer abrasive will have so much work to do.

2) Grind it off, to do this :

-make sure your stones are very clean
-elevate the edge angle (a lot 5-10 degrees)
-go extremely light
-alternate passes

To make life easier on your self, before you sharpen make 1-2 passes right into a moderate stone, say 1000 grit waterstone (medium sharpmaker rods, etc.) this will grind off all the weakened metal on the edge and leave you fresh and strong metal to form an edge, this will drastically reduce burr formation during sharpening.

[Evil D]

That's interesting, i'll definitely give that a try.

[Cliff Stamp]

No worries, bottom line, don't stress about it, while there is a benefit always to having the highest sharpness you can, it isn't functional if it is aggravating you. Step back, use the knife for awhile and then try again later. It isn't like it isn't going to work if it slightly less than optimally sharp. Everyone also has off days, when something isn't going right one of the things I like to do is take a knife which is very easy to sharpen, sharpen that, and then go back to the problematic one with a fresh and positive approach. Yeah it seems all new-age and power of positive thought, etc. but bottom line if you are thinking something is going to be a problem it usually will be.

Sal, Sean, thanks.

[Evil D]

You've really got me thinking about how i get rid of the burr...you may be right about it chipping off and weakening the edge.

Unfortunately, i've just destroyed my Lansky clamp LOL. Long story short i managed to over tighten it somehow (gorilla fingers) and bent the **** out of the two halfs. I'm now one step closer to getting an Edge Pro.