K390 Sharpening

[driftingfir]

I'm thinking of picking up a pm2 in k390 and was wandering how k390 sharpens. I've heard it has a stubborn burr. Any knowledge is welcomed.

[The Meat man]

I had trouble getting a really good edge on my K390 Police until I moved the edge finish up from 240 grit to 400+. It's more a referendum on my sharpening skills (or lack thereof), but moving up in finish helped me get over that difficulty and achieve a razor edge that lasted for a long time. I use a guided sharpening system (Hapstone V7) with Venev bonded diamond stones, and usually prefer maintaining the edge with strops rather than create a microbevel. The strops I use are 14 micron diamond and 3 micron Alumina Oxide, both on basswood.

[Mstach07]

No burr issues for me. Sharpens wonderfully. I use diamond stones and diamond strop compound on basswood. 200 - 1500 stones and 4,2,1, and .5 mic. Touches up nicely back to hair shaving on strops. I am actually thinking about picking up another for backup. Very happy with the PM2 bento box exclusive.

[kennethsime]

I've touched up the PM2 and P3 on the Sharpmaker twice each now and been very happy with the results from just the brown & white stones.

[Bloke]

I'm thinking of picking up a pm2 in k390 and was wandering how k390 sharpens. I've heard it has a stubborn burr. Any knowledge is welcomed.

I don’t have any K390 but a I can’t help thinking it wouldn’t hold a burr.

For what it’s worth, I reckon the two primary producers of burrs are abrasives that are blunt, glazed or loaded with swarf and pressure. :)

[Doc Dan]

I used a Lansky guided sharpener, I used a hand held stone, both gave me no issues at all. I’ve stoped with a leather belt or light abrasive to keep the edge. I love this stuff. It is my favorite non stainless steel.

[SteveMidwest]

I'm thinking of picking up a pm2 in k390 and was wandering how k390 sharpens. I've heard it has a stubborn burr. Any knowledge is welcomed.

It's going to take some good stones, that's for sure. I use SiC stones in the lower grits, and like The Meat Man. I use Venev bonded diamond stones in the middle range. Then diamond film, and finishing it up with diamond paste on a strop. This route, makes short work of K390. It's about as good as steel gets, and you're going to love it! :)

[Albatross]

I've heard the same about K390, but in my experience, it's not difficult to remove the burr. I use diamond bench stones followed by diamond compounds, and the edge I get is amazing. K390 is quite easy to sharpen, relatively speaking, and responds well to stropping too.

I've had much more difficulty with a poorly heat treated 20CV blade from another manufacturer. A single, feather-light pass on a .25 micron strop would create a burr, the entire length of the edge. Now that was a difficult burr to remove at each and every stage of sharpening. Quite a contrast to the 20CV from Spyderco, which barely had a burr during sharpening, and never had a burr past the first few swipes, of the first strop.

[behinDedge]

I'd say: don't be afraid of the burr and get one. You'll need diamond stones and a lot of patience anyway but it's worth it. K390 takes insane edge and holds it so long. It's also very responsive on strops, you won't need the stones often. So far I've sharpened it on stones just once as the factory bevel angle was a bit higher than I like.

BTW, I can't believe these are still available, it's one of the best recent exclusives, have it in my pocket right now :D

[KitsuneSan]

It was quite stubborn to sharpen even on my kme in comparison to s30v or vg10. I really knew I stepped into the big league steals when it took 3x as long. However once sharp it is a beast!

[aaronkb]

I’ve had a lot of trouble with burr removal but that’s a weakness of mine in general, and once I’m finally done the results are pretty outstanding compared with other steels. Takes an outstanding edge and holds it really well, strops back up nicely too.

I use DMT extra coarse, coarse, then fine, 8, 4, 2 and 1 micron cbn strops. Thinking on my next sharpening I’m going to add DMT extra find to the process to see if I can weaken the burr more on the stones prior to stropping. I know I shouldn’t need it, but since that’s something I’m still working on I think it might help.

[GarageBoy]

If one's starting from scratch - what stones should they acquire? Atoma? Edge Pro matrix diamond or cbn? Some sort of venev?

[aaronkb]

If one's starting from scratch - what stones should they acquire? Atoma? Edge Pro matrix diamond or cbn? Some sort of venev?

Depends completely on your ambition and your budget.

[bbturbodad]

I find K390 a pleasure to sharpen and the burr to be one of easiest to remove. Also as others have mentioned it responds well to stropping. K390 is a great steel and Spyderco's heat treat is top notch.

[Bloke]

If one's starting from scratch - what stones should they acquire? Atoma? Edge Pro matrix diamond or cbn? Some sort of venev?

Hi GarageBoy, you can sink a lot of money into abrasive for little to no gain, I reckon. Bitter experience and a few members here (G’day, Jim) have taught me to keep it simple. To that end I sharpen everything with SiC stones and if I find a particular steel is frustrating me I go to a Venev 1200grit bonded diamond.

If indeed there is a “trick” to SiC stones it would have to be Windex and keeping them sharp, flat and fresh by simply flattening on a sheet of glass with a little loose grit SiC and water.

Just my AU$0.02c worth. :)

[Deadboxhero]

If one's starting from scratch - what stones should they acquire? Atoma? Edge Pro matrix diamond or cbn? Some sort of venev?

They all work, the bonded stones don't scratch as deep and make more refined edges, also the stones last longer. The coated (galvanic bond) stuff tears out over time or improper use quickly but is cheaper and does make a rougher slightly more delicate micro serrated edge for those that like that best.

For a fixed angle system I recommend the 120grit JISand 400grit JIS Metallic bonded CBN from Poltava and the new OCB 400 grit FEPA-F from Venev or the 1100- 2200 grit matrix stone.

For Freehand I like Vitrified CBN stones best.

I like to finish all edges with 1um diamond spray on leather.

Technique is king, higher finish will drop aggression and enhance push cuts. Low finish enhances aggression for light draw cuts but drops push cutting ability. One can find the best blend of both worlds I felt with around 1000grit JIS and 1um Stropping.

[Deadboxhero]

The K390 deburrs easy, it doesn't deburr as easy as Maxamet yet not stubborn like the CPM M4 on my Spyderco Military, Mantra, and para 3 dlc Jade g10.

I feel any number of variables could lead one to believe one knife is more stubborn than another since people are all over the place with sharpening.

Anecdotally, one could even think a steel is stubborn if they aren't hitting the right angles when deburring, not weakening and reducing the burr on the stone before stroping and making a massive burr to battle rather than keeping burr formation at a minimum.

So some variables need to be ruled out before coming to conclusions about steel and HT IMO.

I'm thinking of picking up a pm2 in k390 and was wandering how k390 sharpens. I've heard it has a stubborn burr. Any knowledge is welcomed.

[aaronkb]

Anecdotally, one could even think a steel is stubborn if they aren't hitting the right angles when deburring, not weakening and reducing the burr on the stone before stroping and making a massive burr to battle rather than keeping burr formation at a minimum.

I'm thinking of picking up a pm2 in k390 and was wandering how k390 sharpens. I've heard it has a stubborn burr. Any knowledge is welcomed.

I’d be extremely grateful if you ever wanna make a video going into detail on this.

Something I experience often is flipping a burr back and forth over and over and stropping it to death until I’m convinced it’s gone, only to later discover that I’d only aligned it with the edge. It’s massively frustrating to think I have a beautiful edge only to bend the burr over the first time I slice some cardboard. Lately the biggest culprit has been s30v, believe it or not.

[Deadboxhero]

Anecdotally, one could even think a steel is stubborn if they aren't hitting the right angles when deburring, not weakening and reducing the burr on the stone before stroping and making a massive burr to battle rather than keeping burr formation at a minimum.

I'm thinking of picking up a pm2 in k390 and was wandering how k390 sharpens. I've heard it has a stubborn burr. Any knowledge is welcomed.

I’d be extremely grateful if you ever wanna make a video going into detail on this.

Something I experience often is flipping a burr back and forth over and over and stropping it to death until I’m convinced it’s gone, only to later discover that I’d only aligned it with the edge. It’s massively frustrating to think I have a beautiful edge only to bend the burr over the first time I slice some cardboard.

1. Make the burr small.
2. Alternating passes on the stone with almost zero pressure to reduce the burr or remove.
3.You can dust off any remaining burr base at a higher angle on a towel or fuzzy scotch bite sponge.
4. Strop, I preferr 1um diamond.

[aaronkb]

Anecdotally, one could even think a steel is stubborn if they aren't hitting the right angles when deburring, not weakening and reducing the burr on the stone before stroping and making a massive burr to battle rather than keeping burr formation at a minimum.

I'm thinking of picking up a pm2 in k390 and was wandering how k390 sharpens. I've heard it has a stubborn burr. Any knowledge is welcomed.

I’d be extremely grateful if you ever wanna make a video going into detail on this.

Something I experience often is flipping a burr back and forth over and over and stropping it to death until I’m convinced it’s gone, only to later discover that I’d only aligned it with the edge. It’s massively frustrating to think I have a beautiful edge only to bend the burr over the first time I slice some cardboard.

1. Make the burr small.
2. Alternating passes on the stone with almost zero pressure to reduce the burr or remove.
3.You can dust off any remaining burr base at a higher angle on a towel or fuzzy scotch bite sponge.
4. Strop, I preferr 1um diamond.

Thanks for the reply I’m already doing a couple of those, but I’ll work on creating a smaller burr and I’ll give the sponge a try!