Sharperning Titanium

[MikeC]

I own several Mission Knives all with Ti blades, I use a lansky diamond deluxe sharpening system set at 20 degrees, and cannot get the thing as sharp as it was from the factory.

I can get it sharp, but even when sharp I can see serrations in the edge with the naked eye, what am doing wrong? I think I either need to go to 25 degrees or maybe even 30 because at 20 degrees I can see portions of the factory edge that are at a higher angle than the new edge being put on at 20 degrees. Maybe I am using too much pressure when sharpening, or maybe using the wrong sharpenign motion. Other than that I can't figure it out, I am going to try resharpening tonight at 25 degrees and go from there.

The factory edge was just starting to get dull, so I figured only a few strokes with the fine diamond hone would have worked, boy was I wrong. The only stone that puts any kinda of edge on the blade is the course stone, when I got to the medium and fine hones the edge actually gets worse?

Got me wondering.

Any advice would be appreciated.

Thanks in advance

 

[STR]

I prefer a slow moving well used 120 grit belt personally and found on the few ti blades I made that this seemed to put a nice aggressive slicing edge on them quickly. You might write Mission and ask them what they recommend.

STR

 

[richard j]

mike. i just talked with juan from mission knives. he will make a post when he gets time. he goes by juaniosalinas

 

[Jeff Clark]

Titanium isn't steel. It does not hone like your typical somewhat brittle knife alloy. It is abrasion resistant and flexible so it is hard to neatly hone it to a fine low angle edge. I back bevel at something like 15 degrees and finish it off with about a 20 degree angle with a fine grit diamond hone. I consider a fine diamond hone to be a coarse edge. You might need to go even coarser. Titanium kind of needs a coarse finish to cut well. You just can't work a fine smooth edge the way that you would on steel.

 

[MikeC]

Would stropping help, and with what, leather, carboard, pants leg?

 

[Jeff Clark]

From my experience stropping would make titanium duller. (There are a lot of if, ands, and buts about that statement, however that is generally the case). It is hard to cleanly cut titanium with abrasives. It wants to fold out of the way and hang on as a burr or as a rounded edge. My best results are with nice sharp diamond grit honing edge-first. I might make a couple of light stropping strokes on plain leather afterwards, but beyond that I would expect to start rounding and smoothing the edge. I try and leave distinct microserrations in a titanium edge. That's the edge I use on the titanium santoku that I use in the kitchen. (Actually I don't use it much, but my wife kinda liked the lightness of it--now she uses a ceramic santoku or a steel one).

 

[STR]

I think its more as Jeff said. The best edge for titanium blades seems to be an aggressive saw toothy edge like commercial fisherman put on their knives. Something like a DMT 220 grit course diamond or even a 320 grit would do better for you I think.

Stropping is more geared for push cutting very fine edged knives. In my experience this is not the kind of edge that will maximize the usage or ability of a titanium blade and I doubt that you could even achieve a satisfactory edge by stropping or even trying a fine Arkansas stone on titanium. In fact most of the best performing ti blades are micro serrated or combo edges with aggressive serrations that rip through softer mediums like rope and clothing as well as flesh quite effectively in a slicing motion not a forced push through motion like you would be able to do say with wood carving knives you stropped to a fine edge.

The edged titanium weapon is both an agreessive slicing implement and a pry bar in the same tool when it comes together as most higher quality Mission knives and some other customs I've seen and tested.


STR

 

[MikeC]

Jeff and STR, thanks for the advice. If ya'll are right then I've got it done right, that is why the course stone in my Lansky is the one that works best, and that is why I can see little bitty tiny serrations in the edge with my naked eye. I have it sharp enough now to cut paper without any pressure just the weight of the knife, so I guess thats about as good as it gets? Its just when the thing came from Mission it had an edge like a steel bladed knife, the edge was sharp and crisp. The blade stayed that way for a while, then it got dull and when I went to sharpen it, I did something wrong, I think I had and possibly still have the wrong angle, and now I can't get that factory edge back.

John at Mission said he had the burr kings set at 15 degrees, but when I look at teh edge they seem to be more like 25 or even 30, more like 30, as I can still see some of the factory edge and it is steeper than the 20 degree edge that I have now put on the blade.

Nothing like learning on a $400.00 dollar special use tool.

Thanks

 

[knarfeng]

MikeC, whatever device you use to sharpen your Ti blade should not be used afterward on non-stainless steel blades. Ti and non-stainless form a galvanic pair. Once you use your device to sharpen Ti there will be grains of Ti left on it that would become embedded in a subsequently sharpened non-stainless blade. This would promote corrosion of the non-stainless blade.

 

[MikeC]

Knarfeng, thansk for the tip, I had read that long ago, and when I went Mission Ti, I went Mission Ti, I sold every steel blade Knife I had or gave them away. I do have two leathreman multi tools but I have two Lansky diamond sharpening kits, one for just the Mission knives and one for the leatherman's. In fact you can't use whatever you use to sharpen the Ti knives on anything else includign SS, because if you do whatever SS is left on the sharpening device will then be left on the Ti and teh Ti will no longer be non-ferrous and subsaquently become magnetic. Also teh SS chips placed onto the Ti blade will rust out, the Ti will not rust but the stainless steel particles imbedded into the Ti will make rust spots, eventually the rust spots will corrode out.

 

[MikeC]

Got it, went back today for about 10 minutes with teh med grit diamond hone and then teh fine, changed the angle to 25 degrees and used light to moderate pressure letting the stone do most of the work and presto. I can't split hairs but it is SHARP.

Thanks for all of the assitance.