Benchmade Kulgera 930 with S30V steel - having a hard time putting a good edge on it

[Jason B.]

Those are great suggestions!

It's interesting on these forums, because I sense there is something lost in communication, that simply speaking with someone is often superior. For instance, in my note above about desiring rounded bevels, it's easy to intuit that I'm trying to spin my wrist or something to get that. In an effort to explain what I try to do, something definitely gets lost when putting the words down on paper. As you said, simply hand sharpening will produce a convex edge without trying.

The angle I use, or try to use, is basically a hair above rubbing the thumb stud into the stone. Whatever that angle is is the one I usually try to obtain. If that's 10 or 12 or 15, I don't know exactly, but that's the one I shoot for.

I just checked out the Norton waterstones, and they will definitely set me back too much money right at the moment. So I'd prefer to get some wet-or-dry sandpaper and mount it on wood backed leather, at least for the time being. If I do that, and use either water or oil, I should be able to achieve something close to what the stones might produce. Please correct me if I'm wrong. My idea is to start with say 220 grit wet-or-dry with oil. Is that a good idea? Then go to 320, then 400. At that point, perhaps I should switch over to a steel. Please let me know what you think.

Thank you for filling me in on the way Kershaw and others heat treat the S30V. I thought that might have been what was going on.

In the meantime, I'm getting ready to travel, and won't have internet access for a while, and while traveling won't be able to make the provisional "stones" with wet-or-dry probably until I get back.

Thanks again.

Folderguy

PUT YOUR STEELS IN THE KITCHEN AND NEVER USE THEM ON YOUR GOOD KNIVES!!!!!!!!!!!!!!

The norton Sic stone I was suggesting is a oil stone, its made of a very hard abrasive and should make short work of grinding S30V. They are also only about 20 bucks for a 8x2 size. After the stone 400, 600, 1000, and 2000 wet/dry would be ideal and give you a better longer lasting cutting edge.

 

[Franz_N]

I find Benchmade's factory edges to be very flawed, the angles are to obtuse, and to get it sharp they require alot of work, depending on what you have to work with. Everything else about benchmade is great.

 

[Folderguy]

How are you determining edge angle? I'm not understanding how you went from 15 deg per side to 8 degrees?

In my experience very flat bevels and smaller angle bevels get the sharpest. By smaller angle I mean 20 degrees inclusive versus 40 degrees inclusive. Not only do they seem to cut better, but they also seem to actually get sharper as well from my experience.

The 8 degrees is the angle if I take a piece of cardboard and crease it in two, then put the blade inside it and then tape the cardboard at the angle the blade gives. Then check that angle on a protractor. The 8 degrees is the total angle of the knife from cutting edge to the top of the blade on both sides, so if that were to be split in two, it would be about a 4 degree angle for each side.

The 15 degrees up above is the angle from the cutting edge of the blade up to the outside of the thumbstud on each side, so the total is 30 degrees.

 

[Folderguy]

PUT YOUR STEELS IN THE KITCHEN AND NEVER USE THEM ON YOUR GOOD KNIVES!!!!!!!!!!!!!!

The norton Sic stone I was suggesting is a oil stone, its made of a very hard abrasive and should make short work of grinding S30V. They are also only about 20 bucks for a 8x2 size. After the stone 400, 600, 1000, and 2000 wet/dry would be ideal and give you a better longer lasting cutting edge.

The Norton Sic is a silicon carbide stone? In what grit should I get one? 220?

 

[Folderguy]

I find Benchmade's factory edges to be very flawed, the angles are to obtuse, and to get it sharp they require alot of work, depending on what you have to work with. Everything else about benchmade is great.

Well, I also have a Benchmade Sibert 755 Mini Pocket Rocket and it came wicked sharp, shaving sharp right out of the box. Also very easy to touch up, with a different steel: M390.

 

[Jason B.]

The two sided coarse/fine.

If appearance is not important after setting and refining the bevel with the bench stone you could use a ceramic rod to apply a microbevel to the edge. Its a quick and easy way to get very sharp edges, also probably the cheapest.

 

[walleyeguy7]

i had mine extremely sharp, much sharper than when it came from benchmade

 

[Folderguy]

The two sided coarse/fine.

If appearance is not important after setting and refining the bevel with the bench stone you could use a ceramic rod to apply a microbevel to the edge. Its a quick and easy way to get very sharp edges, also probably the cheapest.

Thanks for the info.

The appearance is very secondary to me. I'm looking for performance. Heck, after I open a can with the blade it's going to get a bit scratched up. I didn't buy the knife to baby it or to just look at it; I bought it to use it.

 

[Jason B.]

The microbevel method may be of benefit to you as its fast, strong, and will give you a very sharp edge. This thread will help with understand microbevels http://www.bladeforums.com/forums/showthread.php?t=634739

 

[Folderguy]

PUT YOUR STEELS IN THE KITCHEN AND NEVER USE THEM ON YOUR GOOD KNIVES!!!!!!!!!!!!!!

The norton Sic stone I was suggesting is a oil stone, its made of a very hard abrasive and should make short work of grinding S30V. They are also only about 20 bucks for a 8x2 size. After the stone 400, 600, 1000, and 2000 wet/dry would be ideal and give you a better longer lasting cutting edge.

Just ordered the stone you recommended, and should have it by Wednesday. Getting ready to remove some steel!

Thanks for the suggestion of a specific stone; there are so many others out there.

Folderguy

 

[Folderguy]

The microbevel method may be of benefit to you as its fast, strong, and will give you a very sharp edge. This thread will help with understand microbevels http://www.bladeforums.com/forums/showthread.php?t=634739

Yes, I'm into microbevels, now that I know what they are called. I appreciate the advice.

 

[Folderguy]

And I spent some time honing the edge and getting the effective angle down probably in the 15 degree range. I didn't measure it, but it's plenty flat.

Of course I used the coarse side first, raised a burr on one side, then raised the burr going on the other, then back again just to be sure...

Then switched to the fine grit side and did the same thing. After that, it sliced through copy paper easily.

And then I touched it up with the sharpening steel in the kitchen... uh oh... I'd been warned... sheesh...

And boy oh boy... is that sucker SHARP now... Shaving sharp....

Thanks for the suggestions and advice. It really has paid off.

That blade is d a n g e r o u s now.... :thumbup:

 

[gak]

That blade is d a n g e r o u s now.... :thumbup:

Let's see some pics ! I'm glad you've got it figured out.:thumbup:

For me, if it took me 15 minutes to touch an edge back up to shaving sharp, I'd go bonkers.

Haha ya, luckily with a belt sander resharpening with the leather belt w/green compound takes seconds. When grinding that initial new bevel angle (for fixed blades I like 20 deg/side) you still take a hit though.

I wanted to try out a W2 blade, so I just picked up this little one from Lon Humphrey. I didn't mirror polish the edge because it's going to get scratched up in the forest, but just grinding a 20deg angle/side with 100grit/320grit/20 micron belts, then knocking off the burr with a leather belt w/compound took 30 minutes. It's always worth it afterwards when you don't even feel the blade slide through newsprint.:thumbup:

 

[Folderguy]

I find Benchmade's factory edges to be very flawed, the angles are to obtuse, and to get it sharp they require alot of work, depending on what you have to work with. Everything else about benchmade is great.

Totally agree.

iirc when i thinned my kulgera on the edge pro the thumbstud got in the way at 15°. the blade is quite narrow so that's not suprising.

and judging the height of your bevels you are nowhere near 15°. mine are (iirc again, i gave it to my brother some times ago) almost twice as wide. and with such a wide bevel S30V is quite a pain to sharpen.


hope this helps.

Just measured the bevel after sharpening: right about 18 degrees total (inclusive.)

How are you determining edge angle? I'm not understanding how you went from 15 deg per side to 8 degrees?

In my experience very flat bevels and smaller angle bevels get the sharpest. By smaller angle I mean 20 degrees inclusive versus 40 degrees inclusive. Not only do they seem to cut better, but they also seem to actually get sharper as well from my experience.

I took a hit in the appearance department going so flat (got some inadvertent scratches), but the sucker's s c a r y sharp now!

PUT YOUR STEELS IN THE KITCHEN AND NEVER USE THEM ON YOUR GOOD KNIVES!!!!!!!!!!!!!!

The norton Sic stone I was suggesting is a oil stone, its made of a very hard abrasive and should make short work of grinding S30V. They are also only about 20 bucks for a 8x2 size. After the stone 400, 600, 1000, and 2000 wet/dry would be ideal and give you a better longer lasting cutting edge.

I appreciate the part about the steels, as a ceramic rod will likely be smoother. I can see some toothiness in parts of the blade, as the fine grit on the Norton isn't fine enough, and I don't have any wet-or-dry paper with me to get a smoother edge. Thus I used the steel in the kitchen. Plenty sharp though!! Gonna get one of those ceramic rods.

i had mine extremely sharp, much sharper than when it came from benchmade

Me too.

Let's see some pics ! I'm glad you've got it figured out.:thumbup:

As requested. Sorry for the crappy pics; my poor little point and shoot isn't much good for this kind of stuff, even in macro mode. That said, here goes:

Thanks for looking!

Folderguy

 

[gak]

Ya those sure look like shallow angles, but now you can easily hone it for years just by raising the angle a touch and stropping with your finest stones/leather belt.:thumbup:

 

[futz]

Thanks for looking!

Folderguy

Dude! You rounded your tip off badly. Gotta watch that when sharpening. I did it to one knife before learning my lesson. Never let the tip drop off the stone or do any kind of "flick" at the end of each pass. Just come to a stop, lift it and go again.

You'll lose a bit more metal, but you can grind a new tip back on it fairly easily.

 

[Folderguy]

Dude! You rounded your tip off badly. Gotta watch that when sharpening. I did it to one knife before learning my lesson. Never let the tip drop off the stone or do any kind of "flick" at the end of each pass. Just come to a stop, lift it and go again.

You'll lose a bit more metal, but you can grind a new tip back on it fairly easily.

I did?

I must really not know how to do that then. Do you really consider this tip to be badly rounded off? Here are some closer-ups:

 

[John E Woven]

My 710 came from benchmade with a tip rounder than that

 

[Jason B.]

Good pics and glad things are working out for you but yes that's a very rounded tip. When you get to the end of your sharpening stroke DO NOT swipe the tip off the stone, STOP when you get to the tip and lift from the stone. You also need to sharpen a little more with your coarse stone to get the profile of the edge closer to a Apex. From the pics I can see flat spots and small deformations especially near the tip.

Try and hold a more consistent angle and not sweep the blade in a slicing motion down the stone. Yes, I know this is how most are taught but it is the wrong way. As you push the edge down the stone just lift the handle and in your case only about a 1/2 inch lift is needed to follow the belly of the blade.

With practice you tips will look like this

 

[Folderguy]

Good pics and glad things are working out for you but yes that's a very rounded tip. When you get to the end of your sharpening stroke DO NOT swipe the tip off the stone, STOP when you get to the tip and lift from the stone. You also need to sharpen a little more with your coarse stone to get the profile of the edge closer to a Apex. From the pics I can see flat spots and small deformations especially near the tip.

Try and hold a more consistent angle and not sweep the blade in a slicing motion down the stone. Yes, I know this is how most are taught but it is the wrong way. As you push the edge down the stone just lift the handle and in your case only about a 1/2 inch lift is needed to follow the belly of the blade.

With practice you tips will look like this

Thanks for the tips! (no pun intended )