How should I sharpen this one?

[firiki]

It's about the Glock knife. Here's a nice, short video to give you an idea of the blade's profile.



I have one living in my emergency bag and it's probably the definition of a sharpened prybar. It could cut ropes and cardboard and even paper when I first got it but you couldn't call it sharp.

I gave it a few passes with the ceramic rod found on the dual sharpener by Victorinox just to see what gives: not much, it needs something more substantial. I have no power tools so I was thinking of using a metal file (first a coarser, triangular one, then a finer, round one), then a messed up sharpening stone I use on my pruners and finally some sand paper.

Maybe all this treatment is excessive and unnecessary since this knife isn't meant (by me) to do any real cutting but rather all the nasty jobs that might come up in an emergency, like prying, light digging, batoning and even self defense. All of these the knife can do as it is now but putting a new edge that could be easily maintained in the future would be useful. My sharpening skills aren't very good, I can merely keep an existing edge serviceable on knives.

BTW, I intentionally left the knife without oil just to see what would happen. That was last summer. By February some minor spots of rust had already formed despite the fact the knife was kept in a bag inside the house. 

Any thoughts and suggestions are most welcome. Thanks in advance 

[Tomcat_81]

Similar to sharpening lawnmower blades ;-)
The Glock Feldmesser has a reputation amongst metal detectorists in Austria and Germany- it's seen as the handy, yet rusty prybar that's good for poking around in the ground, but which is best left unsharpened, because the steel is softer than anything which is really made for cutting....
If you want to come back to the initial sharpness (just for the sake of storing it then, awaiting that one emergency) I would also try the files and  some ceramic rods on it, cautiously keeping the angle of the initial edge.
Good luck!

[Grathr]

I havent got one of those, bute a coarse and a fine sharpening stone should get the job done.

Id be careful with the files if you go down that road. I think the fine file should be enough.

If you dont want to use much time on sharpeing, maybe a simple pull throug sharpener would do? It wont get it super sharp, but its easy to use, and will give you a usable edge i no time.

[captain spaulding]

It's about the Glock knife. Here's a nice, short video to give you an idea of the blade's profile.



I have one living in my emergency bag and it's probably the definition of a sharpened prybar. It could cut ropes and cardboard and even paper when I first got it but you couldn't call it sharp.

I gave it a few passes with the ceramic rod found on the dual sharpener by Victorinox just to see what gives: not much, it needs something more substantial. I have no power tools so I was thinking of using a metal file (first a coarser, triangular one, then a finer, round one), then a messed up sharpening stone I use on my pruners and finally some sand paper.

Maybe all this treatment is excessive and unnecessary since this knife isn't meant (by me) to do any real cutting but rather all the nasty jobs that might come up in an emergency, like prying, light digging, batoning and even self defense. All of these the knife can do as it is now but putting a new edge that could be easily maintained in the future would be useful. My sharpening skills aren't very good, I can merely keep an existing edge serviceable on knives.

BTW, I intentionally left the knife without oil just to see what would happen. That was last summer. By February some minor spots of rust had already formed despite the fact the knife was kept in a bag inside the house. 

Any thoughts and suggestions are most welcome. Thanks in advance 

Depending on conditions keeping it in a bag could be worse than leaving it out.

[firiki]

Similar to sharpening lawnmower blades ;-)
The Glock Feldmesser has a reputation amongst metal detectorists in Austria and Germany- it's seen as the handy, yet rusty prybar that's good for poking around in the ground, but which is best left unsharpened, because the steel is softer than anything which is really made for cutting....
If you want to come back to the initial sharpness (just for the sake of storing it then, awaiting that one emergency) I would also try the files and  some ceramic rods on it, cautiously keeping the angle of the initial edge.
Good luck!

I had to Google how to sharpen lawn mower blades; it's pretty much what I had in mind -except I don't have a clamp vise

To be honest, I'm inclined to leave the thing as it is. I can see why it has that reputation and for what I expect it to do it feels perfectly fine. I also keep a Mora Companion and a couple of SAKs in that bag and I hope said emergency never occurs. 

I'm mostly concerned with having to evacuate the building due to an earthquake -we had a good one earlier today 

[firiki]

I havent got one of those, bute a coarse and a fine sharpening stone should get the job done.

Id be careful with the files if you go down that road. I think the fine file should be enough.

If you dont want to use much time on sharpeing, maybe a simple pull throug sharpener would do? It wont get it super sharp, but its easy to use, and will give you a usable edge i no time.

The pull-through thingie on the Vic dual sharpener isn't wide enough for the job and while those can be useful I don't really like them.

I realise that putting a very fine edge on this knife isn't really beneficial, I avoid those in general because they need constant care.

Actually, I was wondering if I should try to re-profile the edge but I'm not sure what result I should go for. I guess I could have mentioned this in the OP 

 

[Steinar]

Sandpaper and a mouse pad, perhaps.

Just do a quick search on freehand sharpening of convex edges if you don't get what I mean.

[firiki]

Depending on conditions keeping it in a bag could be worse than leaving it out.

That's true, the spot wasn't particularly damp, though I keep the bag close to the exit door, that's why I don't want to attach the knife on the MOLLE loops; people would look at me funny.

 

[firiki]

Sandpaper and a mouse pad, perhaps.

Just do a quick search on freehand sharpening of convex edges if you don't get what I mean.

Scary sharp, that was my first thought Then, I figured that this would probably result in a quite fine edge that doesn't seem suitable for this blade. This is how I started wondering if I should try to re-profile the blade, not in a scandi grind fashion but rather try to make it a little less convex (steeper angle near the egde).

 

Edit: Come to think of it, this does sound a bit like a scandi grind, doesn't it

[Steinar]

The idea of the mouse pad is giving a springy layer which makes it easier to sharpen the edge to convex geometry, i.e. "blunter" towards the edge. In other words, my suggestion was to add a convex bevel to a hollow ground edge.

Convex edges are the opposite of hollow ground edges.

Edit: Ah, seems it is a sabre grind, not hollow ground? Doesn't change the idea, though.

[firiki]

I'm not sure what to call that blade profile, that's why I posted the video. I think it's closer to convex but the way it starts tapering so near the spine perplexes me. I doubt I can put a wider bevel on this thing without ruining the edge, though.



Edit:

In other words, my suggestion was to add a convex bevel to a hollow ground edge.

Aren't those two contradictory?  

[Steinar]

Not really, we used to call almost the same thing (derogatory) "round ground" in Norwegian, being the sign of someone unable to hold a consistent sharpening angle.

I tried to draw a cross section of a hollow ground blade with a convex bevel, attached below.

[firiki]

Hey, thanks! Now I see what you mean. The Feldmesser's blade isn't hollow ground, I'm almost certain about that. It actually looks a lot like the grind on your sketch, the only difference being that it tapers much more gradually, thus making me think of it as convex.

The problem is the blade is quite narrow, this is a bayonet after all.

[Steinar]

It's soft steel so stuff like a whetstone or sandpaper will probably work very well. Anything ceramic sucks at removing enough steel to get an edge on something very dull, as you pointed out yourself. (Ceramic hones are my preferred type, whether the steel is hard or soft, but they require the edge to be not too horrible.)

[firiki]

Agreed, I like ceramic sharpeners better too. Sometimes using a whetstone is inevitable though.

For what I expect of this knife I think that I should leave it as it is and just touch it up one bit, which shouldn't be too difficult given this baby's soft steel. I'm just wondering whether a different edge could be better for these tasks. I'm thinking something like an axe's edge maybe. I didn't mention that in the OP though

[Syph007]

For that type of work I would just file sharpen.  Thats how I do cheap machetes that arent blade steel.

[firiki]

I'm thinking the same, a few strokes with a file and a little sandpaper to smooth the edge a bit in the end.

It's not worth messing up my whetstones even further and I might even find some inspiration and get creative in the process