Recommendation? What grit do you use for profiling

[maximus83]

Absolutely give it a try. The EDC I posted earlier was taken to a zero grind at under 7 dps. This Fehrman below has a combo 1K/3K finish with a random, mottled pattern. A 240 finish would have decreased stain resistance significantly over the original satin.

View attachment 780510

That's cool. How long does it take to do something like that? I have a knife in mind I could use. Wondering if my Atoma would be up for the job.

 

[adamlau]

Anywhere from 20 minutes (accepting of the natural pattern as a result of an uneven stone and/or blade plane) to several hours (modulating pressure to create a specific pattern). The Atoma 140 will produce deep scratches. OK to start with if you plan on a progression. Though a coarse SiC would constitute a far more cost-effective alternative.

 

[David Martin]

Yes, to reprofile say from 19* to 14* most of mine take 10-15 min. work on the coarse stone. A little more for harder steels like S30V. Then 5-6 mins. for each grit higher to remove the scratches and refine the bevel like you want. DM

 

[maximus83]

Anywhere from 20 minutes (accepting of the natural pattern as a result of an uneven stone and/or blade plane) to several hours (modulating pressure to create a specific pattern). The Atoma 140 will produce deep scratches. OK to start with if you plan on a progression. Though a coarse SiC would constitute a far more cost-effective alternative.

Well I suppose I could use one of my Norton economy stones, I forget if those are SiC or AlOx. I think it's like 100 grit on the coarse side. Why it would be more cost effective? I already have an Atoma so in my case, it's available to use.

 

[jpm2]

Well I suppose I could use one of my Norton economy stones, I forget if those are SiC or AlOx. I think it's like 100 grit on the coarse side. Why it would be more cost effective? I already have an Atoma so in my case, it's available to use.

This is what I use to hog metal off fast. My diamonds are mostly saved for truing and finishing.

 

[maximus83]

Man, this afternoon I spent a little time with that huge, 0.23" thick carbon steel Schrade that I've been practicing with and had the burr issues. Today, I tried using the new Ultrasharp 300. Made headway on the burr, and love the Ultrasharp, but on that big slab o' metal, it didn't cut fast enough for my liking where I was trying to quickly rework the entire edge after grinding off a big burr. Next up: the Norton economy stone or my my Atoma 140. Definitely seeing the role for a super coarse stone in the lineup.

 

[David Martin]

This is good. You're learning. DM

 

[maximus83]

Tried the Atoma 140 tonight on a soft stainless. It is just fantastic for fast clean edge profiling, I can get a really nice clean edge bevel from heel to tip in minutes with very light pressure. Love it, easy on my neuropathy-ridden hands! Then I went from the Atoma straight to the Arctic Fox and it worked pretty good, but took a while.

In my (admittedly limited) collection of stones, the Atoma is now my stone of choice for profiling work. After that, it's a bit tricky figuring out the next best grit step. I got good results last night going from Atoma to a 300 diamond stone. I almost wonder if it's too big a jump going from the Atoma to the 400 Arctic Fox, because it takes the AF too long to clean up the coarse scratch pattern produced by the Atoma. It's almost like when profiling I need to go Atoma > 300 diamond > AF > EF diamond. More grits/stones than I really want to use, but ironically using that extra grit like the 300 diamond speeds things up quite a bit.

 

[brasileiro]

It depends what do you mean with profile or reprofile.
For me profile refer to the blade shape or bevel geometry (not blade geometry like full flat, hollow grind...) i.e. build (design, cut and grind your own blade) or change a straight bevel blade like Kershaw Leek to a recurved bevel blade or transform a spear point to a tanto.
In this case my guess is a file if you can’t do the heat treatment. Or a hacksaw to cut the main piece to be worked.

 

[HeavyHanded]

Yes, it depends on what you mean by reprofile, and whether the knife in question has ever been reset properly after it left the factory.


I begin almost every job with an XC DMT or the coarse side of a large combination stone - the rougher the better. My goal is to get the bevel reset and onto the next stone ASAP. Every other stone progression after that will go faster - much faster. If I'm trying to avoid deeper scratches or undue loss of steel I'll stop short of the apex and take it to the edge on the next stone up - usually an 800 or 1k or fine DMT equivalent.

This method really became cemented as I began to do more chisels and plane irons that need a lot of metal removed to restore the working bevel - I don't like using power tools on these if I can avoid it, so I pound through the grunt work on the roughest stone/surface I have that still manages some precision. Again, on the really rough stones I try to stop short of the actual edge if possible. If not I'll still spend a little more time on the next stone up as there is often significant burring and plastic deformation at the apex when using rough stones with a lot of pressure. I remove all that.

If its a quick job I go right to a microbevel off the coarse stone. In that case I DO go right to a burr or three finger sticky but with a lot less pressure at the finish, then on to the polishing stone.

 

[maximus83]

Yes, it depends on what you mean by reprofile, and whether the knife in question has ever been reset properly after it left the factory.

What does it mean to reset after it left the factory? Also, what do you see as the difference between reset an edge, and profile an edge?

 

[HeavyHanded]

What does it mean to reset after it left the factory? Also, what do you see as the difference between reset an edge, and profile an edge?

When a knife leaves the factory, the edge has probably been done on a belt or other narrow contact abrasive. It is likely if not probable the edge sways and changes angle slightly along the length. All of this is going to show on the first real sharpening done on a flat surface, and this takes the most time to do. Touchups after that, even if changing the angle, tend to go a lot faster.

I'm not sure if reprofile and reset are interchangeable but maybe so. 'Reset' to me is the act of reshaping a dull from shoulder to apex with a rougher stone.

 

[maximus83]

Found the best combination yet--in my small collection--for resetting (profiling?) an edge bevel all the way through sharpening. This took about an hour total, as this cheap blade had a totally boogered edge from--shall we say--earlier "experimentation" by someone. The sequence was about 30 minutes of completely redoing the edge bevel at I'm guessing around 15 dps on the DMT. No micro. First the DMT XC to rework the edge bevel. Then about 40 or 50 passes per side on the AF to blend and apex. Then 5 feather-light passes on the Ptarmigan. At this point, it meets all the standard tests: shaves arm hair with almost no friction, 3-finger sticky, and both push and pull cuts in newsprint. Finally, I added about 10 stropping passes per side on the basswood.

DMT XC (220) > Arctic Fox (400) > Ptarmigan (6k/3 micron) > Basswood + compound (Tormek 8k)
Pictured left to right:

And the resulting edge. As usual, some struggles around the tip and heel, but it's super sharp and a fairly consistent bevel.

Some takeaway observations:

• The stropping step added very little that I could tell. Cutting performance was no better after than before, although the edge was noticeably smoother and I assume more aligned. I could easily stop sharpening after the Ptarmigan step and all would be well.
• The DMT XC is, in my setup, the best starting point for ordinary sharpening where some edge reset/profiling is needed. It cuts fast and cleanly, doesn't leave such a deep scratch pattern to clean up as the Atoma, therefore saves me time.
• The AF is the best "jack of all trades" stone that I have. I could easily have simply stopped sharpening after the AF, the knife would already perform the above sharpness tests, though it got noticeably a LITTLE better after using the Ptarmigan to finish.
• I'm not seeing the point/need of an "EF" (say 1000 to 1200) type of stone in this setup. I have these stones (a DMT EF, and an Ultrasharp similar). Does it even add anything useful?

 

[maximus83]

It also depends on the stone vs steel, the harder & more carbide rich the steel, it will be scratched less deep than a simple carbon steel.

In my case, diamond at 300ish is lowest I’d go for simple steel like 8Cr13MoV, mostly I start at 600 diamond.

That makes sense. I've been finding as well that with the softer steels, I can get away with starting with higher grits. What do you start at with your super steel, high vanadium content blades?

 

[maximus83]

You might hear some people mention how certain steels like a certain type of stone over other types. I've come to feel that most ordinary kitchen knives like a simple aluminum oxide oil stone; the two go well together, and produce edges that work very well for kitchen uses (or more). This isn't to say that something like a Fine/EF diamond hone can't also produce great edges on such knives (I like them with Victorinox blades, in particular). But, you don't necesarily need anything extravagant or overly aggressive for such knives.
David

Totally get what you're saying about the idea that certain steels seem to work best on certain stones. Just from observation, I can see that is the case. My "super steel" blades all totally prefer diamonds, obviously, because of the hardness issue. My softer stainless steels, including my kitchen knives, seem to like that Arctic Fox 400 AlOx stone more than any stone I have, or have ever tried for that matter. You can literally just use that stone alone with these steels--for everything including edge reprofiles--and get fantastic edges.

 

[FortyTwoBlades]

For rough work, I LOVE a Crystolon. Silicon carbide, chews thru steel, constantly releases abrasive. Dishes, but pretty easy to flatten. I don't like diamond plates for that work, either. A good coarse stone is a pleasure to work with. I have a Sigma 120 silicon carbide, it has no binder (if I recall that right, it may have a ceramic binder), it's like solid SiC. But it is SUPER porous, hard to keep water on it, and needs to be conditioned once in a while with loose SiC. I even use it under running water to help with the porosity issue. Also bought a Baronyx Manticore (black and green SiC). It's like the Sigma, but has a ceramic binder that seems a little weaker (better for me) than the Sigma. Also have a Baronyx "Bull Thistle" synthetic ruby stone about 120 grit that eats thru steel as well. LOVE that one, too. I keep going back to the Crystolon for thinning/edge setting/rough work. It just has good properties. One stone I have become a little disappointed with (but it's hard to complain with that low price), is the Baronyx "American Mutt". It's a good stone, don't get me wrong, but I don't find it to eat thru steel very well. It seems harder than it should be, it does give a higher polish than it's rating. Didn't mean to make this about my stone review, but maybe it helps.

If memory serves correctly, the Mutt you have is a first generation one, in which case it will only shed grit under very heavy pressure. Current generation ones are done at 90% press rate compared to the originals, and (while still a hard bond stone) sheds grit much easier now.

I find its best application is dealing with edges that have been totally blunted, such as common kitchen or pocket knives owned by non-knife people.

 

[Chris "Anagarika"]

That makes sense. I've been finding as well that with the softer steels, I can get away with starting with higher grits. What do you start at with your super steel, high vanadium content blades?

Unfortunately I only have 360 Taedea diamond. Or DMT C credit card.

 

[maximus83]

Hey, if it works on your blades, it works. I hear you with the DMT. Couple nights ago I tried out my new DMT folding XC/C sharpener, even that tiny little thing could do an awesome job of profiling an S30v blade on the XC side.

Unfortunately I only have 360 Taedea diamond. Or DMT C credit card.

 

[Chris "Anagarika"]

When I’m feeling impatient, I’d use these two instead of 600 even for VG10. The downside is it requires more clean up due to deeper scratches.