Anyone have some advice on sharpening?

bodog

bodog

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Why is it that I can get S30V, elmax, s110V, S35VN, etc screaming sharp, as in hair whittling, but when I try for a carbon steel like 1095 I just can't get it as sharp as I'd like, as in cleanly slicing newspaper but not push cutting it? It's actually a Damascus blade of 1095/15n20 and I got it from a reputable maker.

I have tried scrubbing with stones, edge leading only, etc. I make sure I raise an even burr and that it's completely gone when I'm done. I can sharpen more abrasive resistant steels easier and the whole reason I went for a carbon was for the ease of sharpening and the thought that I could raise my standard in sharp knives. I go up to 1500 or so grit stones and then strop up to 14,000. So far I'm disappointed in my efforts. Any thoughts on what I may be doing incorrectly? This is my first quality carbon steel knife and don't want to unfairly judge it if it's me. My thought is that the same method I use on the stainless blades should work for a carbon steel. Is this incorrect? Thanks.
 
What stone types are you using (diamond, SiC, AlOx, waterstones, etc.)?

1095 steel (by itself) usually responds to 'simpler is better' sharpening solutions like simple AlOx, SiC (stones or sandpaper) or Arkansas stones, followed by stropping with white or green compound on leather or fabric (like denim). A Fine or EF diamond can be used for re-bevelling it, if it's convenient. Some manufacturers' versions of 1095 can be of horrible quality, and others can be excellent. As part of a damascus mix, the steel could be a toss-up however. Damascus can be pretty unpredictable in how it sharpens up or how well it holds an edge.


David
 
mixed steel blade not san mai?
It could be exactly because of the composition.
 
My thoughts are that you are over sharpening it and in the process rounding the edge. I've found that with 1095 as stated above responds to less is more. In the end, inevitably you can't keep the angles through multiple medias and processes so it ends up being more rounded than you'd like.

Maybe try a test of cutting performance between each step and see where it falls off or at least where the work becomes futile.
 
As far as I know they're alox but I really don't know. They cut just about like alox. they're cheap chinese stones. they work very well with the harder more abrasion resistant steels so I figured they'd be good for a steel like 1095. I don't know how the 15n20 pattern welded into it would affect it. honestly, even as sharp is what it is, it doesn't have a very good cutting geometry. my s30V spyderco military at what, 61 hrc or something, is a scalpel. it whispers through paper. tree topping sharp. I can push cut newspaper with my zt 0561. used the same stones as the Damascus. I clean them well between and during use so I know they're not clogged. I've tried leaving swarf and not. doesn't seem to work either way.

I left it at about 400 grit and burnished it with some simichrome yesterday to check. it cuts about the same as when I go up to 14,000. slightly toothy and not great at push cutting. my strop compound is diapaste so I'm wondering if it's too aggressive which screws it all up and leaves it as dull as the 400 grit hone.


you guys think going with some alox or sic strop paste would perform better than the diapaste? you think it's probable that it's the steel? I hope not, I've wanted a quality Damascus knife for a long time and would hate for it to be the knife instead of me. I can fix me, I can't fix a knife with so so steel.
 
bodog said:
As far as I know they're alox but I really don't know. They cut just about like alox. they're cheap chinese stones. they work very well with the harder more abrasion resistant steels so I figured they'd be good for a steel like 1095. I don't know how the 15n20 pattern welded into it would affect it. honestly, even as sharp is what it is, it doesn't have a very good cutting geometry. my s30V spyderco military at what, 61 hrc or something, is a scalpel. it whispers through paper. tree topping sharp. I can push cut newspaper with my zt 0561. used the same stones as the Damascus. I clean them well between and during use so I know they're not clogged. I've tried leaving swarf and not. doesn't seem to work either way.

I left it at about 400 grit and burnished it with some simichrome yesterday to check. it cuts about the same as when I go up to 14,000. slightly toothy and not great at push cutting. my strop compound is diapaste so I'm wondering if it's too aggressive which screws it all up and leaves it as dull as the 400 grit hone.


you guys think going with some alox or sic strop paste would perform better than the diapaste? you think it's probable that it's the steel? I hope not, I've wanted a quality Damascus knife for a long time and would hate for it to be the knife instead of me. I can fix me, I can't fix a knife with so so steel.
Click to expand...

I'd try a different strop compound FIRST THING. I've avoided using Dia-Paste on simple steels like this, as they can over-polish them very easily. SiC and black emery compounds may also do the same thing. Try some green compound instead, or perhaps some white rouge compound. Look for white compounds labelled for polishing stainless steel; I've got some Ryobi brand white rouge that works very well on a wide range of steels, including 1095 and similar steels. For the final touches though, I like green better than anything else, on 1095.

Make sure you've got a nice, crisp and somewhat toothy edge from the hones first (should be sailing through paper at this stage; maybe with a little snagging from burrs & such), then try the green following that. If you think you want to polish the edge a little more, then try the white.


David
 
I'll give it a shot. I love a mirror polished edge but that just might not happen til I can get some different compound. I'll try using the 1500 grit stone followed with the simichrome and plain cardboard tonight.
 
bodog said:
honestly, even as sharp is what it is, it doesn't have a very good cutting geometry. my s30V spyderco military at what, 61 hrc or something, is a scalpel. it whispers through paper. tree topping sharp.
Click to expand...

I've noticed that thick bladed knives, which usually have steeper edge bevels, really do have poor cutting ability, even on something simple like phonebook paper. I can do my exact same sharpening steps, use the same tools and techniques to form a burr, then remove the burr... I can everything just about exactly the same between a thin bladed knife and a thick one... and the thick one won't cut phonebook paper impressively. It certainly shows that it is sharp, and most of these blades I've done will push cut some, but they also tend to snag, especially as the blade begins to curve.

This could simply be my lack of precision, or my lack of attention to detail. I'm not sure. But I've definitely noticed it.

Regarding your desire for a mirror polish on a carbon steel blade: I rarely sharpen carbon steel, but I'm remembering an Old Timer folding blade I did for a coworker something like 2 years ago. I finished that blade on a Norton Fine India stone (AlO2) and was *shocked* when I looked at the bevel. It was a very bright near mirror right off of that relatively coarse stone. Moving to Spyderco Medium and Fine made it a bit brighter and a bit sharper. The owner was very pleased with it's performance. So you may not need anything super special to get a nice highly polished edge.

Good luck.

Brian.
 
Ok, so I just went back and used my 1500 stone dry. of course it clogged easily but it seemed to do the trick. it at least cleanly shaves hair off my arm in one pass so I'm getting there. Don't know why allowing the stone to clog up works better but it is what it is.

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You might be using a bit too much pressure in general. The higher RC, higher carbide content steels can handle that a little better, the carbon steels not so much. Maybe letting the stone load up tamed it a bit? Most of my carbon steel tools respond very well to a hard backed strop, and not too much of it - very easy to round it off a bit.
 
Ok, so I went wood whittling yesterday and the edge held up great. I guess I was just used to the harder steels. I think I was, as stated in the last post, rounding my edges while stropping. I took my time and very lightly and very cautiously stropped it up and it's fine. Thanks for the advice guys.
 
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