Testing a Few Questions

I used a Lansky for a decade+ and switched to a belt sander. If you dip the blade in icewater as you sharpen I've noticed no problems with any edge. The array of grits and the leather finishing belts w/compound make the belt sander too quick and easy not to use.

With the combo of moving the blade steadily across the belt and keeping it cool in with the icewater, I rarely ever feel a blade get warm nevermind hot.

Infi, S90v, S30v, 154cm, VG-10, L6/O1 damascus, O1, Carbon V, they all love the sander.:thumbup:

bubblejig-sharpen2.jpg

bubblejig-sharpen1.jpg

emmons-rc6.jpg

nmfbm-savagebeast.jpg

deadwoodsavagebeast.jpg
 
althoufh i'm not denying what gator said about the softer steel not being able to work on superhard , high rockwell alloys ;my question is : if this is valid how is it that cardboard & leather can still be effiecent on the super r.r. metals?
 
Update on the Cara Cara. I got up to 185 cuts and steeled the edge with the Faberware chef's knife. Back to shaving sharp. I'm really amazed that I missed the benefits of steeling for so long. Got more aluminum to cut. I'll see how long it lasts.

Dennis, my guess would be the steel has more of a chipping effect on the harder steels. That is the reasoning behind my wanting a flat steel instead of a round one. The harder steels may bite into the sharpening steel, but I don't see that being a problem unless too much force is being used, enough to likely chip the blade anyway.
 
i certainly agree with gak as to using belts to touch up an edge . however as evidenced by his photos he is a true xpert with power equipment. one slip on a belt can ruin your day[ not to mention the knife]. the steel is quick , has no setup time & as long as it is clean it's hard to screw up. years back before i got it together i burned a lot of knife tips.these days i rebevel holding the blade in hand with a bucket of h2o handy.i use the steel or stroup to touch up the edge & leave the more drastic profiling to the belts. actually if one has a deer camp set up with several guys bringing in game the steel is the way to go since a bloody knife messes up a stroup.me2 check out resturant supplies, the Dick multisteel is an almost flat oval steel.it's a lifetime investment since they are xpensive.
 
DennisStrickland said:
if this is valid how is it that cardboard & leather can still be effiecent on the super r.r. metals?
Click to expand...
Do you mean how leather strop can restore the edge? Perhaps the higher pressure or an abrasive compound in it?
On this photo below, I was unable to realign the deformed edge on Watanabe nakiri, Aogami I steel, 63-65HRC with 50 strokes per side on a plain leather strop, but 5 strokes on borosilicate rod did the trick.

On the other hand if I use 0.3mic sandpaper or 0.25 mic diamond loaded leather it restores the sharpness quickly, on the same knife, but obviously that's not realigning.
 
I've kindda lost track of your test :) It started with cardboard right?
Now you are cutting Aluminum? And no difference between what and what?
 
we're really talking about different parameters on this alighning of the edge trueness. no doubt diamond paste on a leather stroup is going to be more efficient than chrominum oxide & certainly boron silicate is going to be a very quick answer to realigning the teeth of edges. we are working in different mediums so our opinions are diverse but all things being = certainly the hardest most agressive surface will probably achive the result we want the most rapidly.we need to use the smallest micon size we can so that we do'nt cut our edge off. if i'm not getting the message please explain.
 
I suppose some conclusions are needed here. I did not answer the original question that I set out to answer. However, I did discover that steeling an edge has a place in my sharpening cycle. I also discovered that neither cardboard nor sheet aluminum are particularly abrasive, though the aluminum will require further testing. Dulling happens primarily from edge rolling, not abrasion, at least on these 2 cutting media. Use of a steel will extend the time between metal removal sharpenings many times, and thus the life of the knife will be greatly increased. I used a smooth steel in the form of the side of another knife. The standard serrated steels may work, but they were not used here. I have found in the past with other knives that they can catch the knife edge and dull it rather than sharpen it. Therefore, I advocate the use of smooth steels instead. No chipping was noted with either knife, cutting their respective media, so metal removal was not needed to bring back the edge of these knives. Having cut aluminum cans with the Food Network knife in the past, I can say no chipping was noted then. No notes were taken on the amount of cardboard cutting between steelings of the FN knife, though as cutting progressed, the time between steelings was not noticably shorter. The amount of cutting between steelings is being noted on the Cara Cara.

I started off cutting cardboard with a Food Network kitchen knife. That proved an excercise in futility, since cardboard just didn't dull the knife quickly enough that steeling the edge with a smooth steel couldn't bring it back. I then switched to a Cara Cara and cutting aluminum cans, since I'm out of cardboard. Nearly 200 cuts later, it would still scrape shave hair off my arm. I then steeled the Cara Cara's edge back and it shaves again easily. I didn't notice a different between the magnified pictures in the post above.
 
Interesting results :) I did my test today, on what I suppose was also Aluminum. Except after single cut, about 7cm long, the edge on poor calphalon was rolled so badly I couldn't restore is neither with borosilicate rod, nor with stropping. I did use much greater pressure, after I failed to restore the edge with light strokes, based on your input here, I thought may be that was the important factor, but no...
Nothing helped.
I'll post micrographs tomorrow, but the roll is clearly visible with naked eye, and I can still feel it with my fingertip. Steeling /stropping did improve the edge, i.e. reduced the roll size, but didn't remove completely.

Out of curiosity, what was the thickness of the Aluminum you were cutting and how did you cut, push cutting or slicing?
 
It was a standard soda can from the US, so pretty thin. The motion I use is a slice, but there is no sliding on the edge. For a 3 inch blade, I'll cut 3 inches of Al, or very close.
 
me2 thanks for the specs on your test medium & most importantly the length of cuts. my trepidation is when using a soda can i might cut myself.
 
me2 said:
I didn't notice a different between the magnified pictures in the post above.
Click to expand...
On the top part, the shadow cast by rolled edge is clearly visible, and not on the bottom one.

I was really curious why aluminum produced different results for mine and your tests. I am quite sure the thickness is the culprit, granted you have 30deg inclusive edges on your knives, well may be Calphalon is way worse metal than 440A at 54-56HRC, but unlikely, see below. BTW, can you measure the thickness if it's not a standard can?
Standard soda can wall is ~0.07mm thick, in my first test last weekend, I was using Aluminum that was twice as thick, 0.14mm and the last test I did yesterday was with 0.22mm thick Al, that's a little over 3x the thickness compared to soda cans.
I did cut a soda can in half, horizontally, today with Calphalon, single cut, using approx 1" of the blade, the result was pretty much the same as your test, it didn't even loose shaving sharpness, although the cut was considerably longer compared to the yesterday's test.
 
Ah, now I see it. I'll try to measure tomorrow when I have some calipers. I think my edges were actually put on with the 20 degrees slots on the Sharpmaker, with a 17 degree backbevel, considerably thicker than yours in the tests.
 
Update on the Food Network knife. The steeling worked for a while, but after it was returned to normal kitchen use, it chipped very badly over the length of the blade. Some are quite deep, deeper than the steeled section of the edge, so I can't say that the steeling had anything to do with it, but it seems more than a coincidence that I steeled the blade for a lot of cutting then had chipping like this after returning it to regular duty. It has chipped before, but when using 12/15 degree edge/microbevel, and never to this extent.
 
Interesting. I love the effects of steeling, but always wondered about the long term strength and durability of the edge. But it still could be a coincidence...
 
me2 said:
Update on the Food Network knife. The steeling worked for a while, but after it was returned to normal kitchen use, it chipped very badly over the length of the blade. Some are quite deep, deeper than the steeled section of the edge, so I can't say that the steeling had anything to do with it, but it seems more than a coincidence that I steeled the blade for a lot of cutting then had chipping like this after returning it to regular duty. It has chipped before, but when using 12/15 degree edge/microbevel, and never to this extent.
Click to expand...

I've come to believe that steeling does indeed "sharpen" the edge, that is it removes metal and imparts a fresh set of micro-serrations. My father-in law was a mechanical engineer specializing in blade design for over twenty years - "A steel is nothing more than a very fine file, very easy to wreck an edge with one" he said over a carved turkey a couple of Thanksgivings ago. If it was only needed to realign the edge then a smooth glass rod would work better than anything, however for a steel to give good results it needs to have some abrasive quality. Your technique with the steel must be rather solid. I use a steel on some of my kitchen knives as a quick and dirty way to restore an edge, but the quality of the edge is not as good as with a stone or ceramic hone, and is (in my experience) very prone to the creation of wire edges. That's fine for kitchen use, but when I've experimented with using only a stone instead of a steel I get somewhat better performance (longer time between honing) but it's just not very convenient. For my two most heavily used kitchen knives I've adopted a secondary/primary bevel stroke that works quite well. I have suspected that this results in a weakened edge over time, but since my loop only goes to 30x it's difficult to say exactly what's going on. Something on the order of 300x is probably what's needed.

Great test, thanks for the effort and sharing the results. Do you have any way of determining what angle you were steeling the knife at?
 
This is actually the first time I've used a steel extensively. I'm only guessing at the angle, but somewhere between 20 and 25 degrees. It really depends on your definition of "sharpen". If you mean it makes the knife sharper than when you started, then yes it sharpens, regardless of the mechanism involved.

This is why I prefer smooth steels to the "files" that most knife blocks come with. This test was done using the side of another knife as the honing steel. I strongly suspect this extended steeling and cutting session weakened the edge, but there are too many other variables to say for sure. I recently found a void in the edge of the knife, so more of those may be more to blame. Its a small, round hole in the side of the bevel. I uncovered it when I was using my belt sander to rebevel the knife several months ago.

If you haven't already, have a look at Verhoeven's sharpening paper. He uses smooth steels and found that going from a 1000 grit waterstone to a steel produced no improvement, but going from 600 grit and coarser to the steel showed considerable improvement. The steels he used did scratch the edge surface, so in that regard I suppose they did remove metal, but that was not the contributing factor in the improvement of the edge. They actually folded the wire/burr from the coarse stones to one side and plastered it to the side of the bevel, leaving a smoother, narrower/sharper edge.
 
I'll have to take a look at the paper. My own experience is somewhat similar, but limited in observation to what could be seen with a 12x and 30x loop. I could clearly see a large difference in the appearance of the edge grind going from a 750 grit diamond stone to a smooth steel. I did observe as well that it required an almost intuitive feel for when to stop. Steeling past the point where I had smoothed out the grind texture to what the steel was capable of, inevitably resulted in a burr/wire edge. I have to say as well, that when I compared the before and after to an edge that had been stropped or honed on a hard Arkansas stone the edge appeared to be considerable degraded (seen at 30x) and the edge did not last very long (comparatively). Additionally, steeling an edge that had already had most of it's grind texture removed/polished on a fine stone or stropped, resulted in a wire edge in a very short number of passes unless I increased the angle the point where I was in effect creating a whole new bevel. That's the point where I adopted the attitude that my steels were for quick and dirty sharpening, and in fact haven't put my two most heavily used kitchen knives to a stone for going on two years, they're both shaving sharp, but the edge looks pretty raw ( the grind pattern is very erratic compared to a stone) under magnification and likely wouldn't last long for any sort of utility use. Trying to delve into the dynamics of sharpening on a deep level without some fairly powerful imaging tools and consistent testing media is like jumping down the rabbit hole. FWIW I stopped using steels on my pocket hardware because I don't like to refine the toothiness of my EDU knives beyond 750 grit or so. From what I can determine, that's about the point where an edge wears the longest for general use and has good push/draw cutting characteristics. Going with a grit less than that results in considerable improvement for draw cutting and a noticeable degradation in press cutting. Going with a finer edge starts to result in a degradation in draw cutting and a considerable improvement in press cutting.

At least that's what I've found...
 
You must log in or register to reply here.
Back
Top