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My Attempt at Honing a T.I. to Feather Like Sharpness with pics!

Hi all,

The genesis of this thread can be found here.

I am documenting my attempt at honing a T.I. Super Gnome to Feather like sharpness. My current honing equipment consists of a complete set of Spyderco hones, a Hand American base, one leather plate for it loaded with CrO, one glass plate for it with nothing on it yet(I was planning on trying some of the 3M micro abrasive papers on it) and a nice hanging strop from Tony.

The first step is to identify a goal and see what the edge of a fresh Feather Professional Super blade looks like. Here is just such a blade under various magnifications and lighting conditions:

Feather Pro Super at 60x, Front Lighting


Feather Pro Super at 200x, Front Lighting


Feather Pro Super at 60x, Side Lighting


Feather Pro Super at 200x, Side Lighting


Feather Pro Super at 60x, Edge Lighting


Feather Pro Super at 200x, Edge Lighting


We can observe a few things. We can see that the honing scratches have been completely polished away leaving a very smooth edge. They are using a very fine grit in the final honing & polishing stages. This appears to be a VERY sharp edge! We can also see that Feather uses three bevels on their edges. This in undoubtedly for efficiency. The tiny size of the third bevel, clearly seen in the edge lighting micrographs, also explains why these edge don't last long. We can also see how uniform and completely smooth the third bevel is.

Now we know what we are aiming for.

The next step is to begin to hone my T.I. Super Gnome, hereafter referred to as the SG. I just purchased this razor from classic.

Here is the blade before we begin:



I decided to use the old trick of marking the blade edge with a permanent marker in order to see where the hone is removing metal from and gauge progress towards a uniform bevel.

Here is the blade as marked on both sides:



I then proceed to give the blade 10 round trip strokes on the Spyderco Medium grit hone. I was very careful to keep the blade flat on the stone, not raising the edge or spine and used very light pressure.

Here is the result:



Right away I have encountered a problem. The hone is clearly not removing metal evenly across the length of the blade. The bevel is not uniform. While it appears the most of the bevel is in contact with the hone, the heel and toe are not. In fact about 1/3 of the blade from the toe down is not being honed and the last 1/2 centimeter near the heel has the same issue.

Here are some micrographs of the edge at 60x:

Mid blade


The bevel is uniform here and the marker has been removed all the way down to the edge. This is what we want to see all along the length of the blade.

Here is the edge 2/3 of the way up towards the toe:


The bevel is not uniform here or in complete contact with the hone. There is a strip near the edge where the bevel does not extend all the way down. We are not sharpening the edge at this point, just setting a new bevel. Of course the problem gets worse the closer to the toe we get as seen in the next two micrographs:

Nearer to the toe



Proceeding any farther at this point would be useless as the bevel is not uniform. So now my question is what to do? I've been sharpening knives and woodworking tools for years and normally at this point would drop down to a lower grit and keep on honing until the bevel is uniform and metal/marker is being removed along the entire length in every stroke. I'm not sure that is the right course in this case as I'm still new at razor honing. What say the honemeisters? What should I do?

Thanks,
Joe
 
Me three on the getting a uniform bevel on a lower grit :biggrin:

What is reserved???

Anyway, let me point several things:
  • Even if you get the straight looking as Feather, it doesn't mean that it will shave as a Feather, etc. - the emphasis must be on results and feel comparing the two, and maybe using the visuals as a helping tool
  • As I mentioned in another thread - it's not that the scratches on the Feather are totally polished - but rather that there are 2 or 3 coatings on the edge
  • Actually, the multiple bevels on the Feather are designed to give it max longevity (I think this was explained like this: the cut hair is easily pushed to the side, and there is less force than if it were only one bevel; there was also something for width / extra support due to the wider bevels after the edge); if you get the same sharpness with a single bevel on a straight the edge should be less robust
Cheers
Ivo
 
He's reserving the next few comments so he can go back and edit them to put in the next steps of his process.

As for the OP: 60x is nowhere near high enough to tell what the feather is really like at the cutting edge. Prof Voerhoeven has a monograph on sharpening that has been previously linked from this site, and if you download it you'll see some photos of razor edges at 3000x, including shots straight at the edge itself - that's the sort of resolution you need to see what the edge is doing. In particular it allowed him to measure the width of the cutting edge on a variety of steels, hardnesses, grits, and honing methods, and what he found is that both commercial razor blades and straight razors are exactly the same sharpness. He demonstrates that this sharpness was achieved pretty easily using diamond abrasive pastes of about 9 micron size, using finer pastes all the way down to 0.5 micron chromium oxide did *not* reduce the width of the cutting edge.

As Ivo has previously alluded, the reason straights don't seem as sharp as commercial blades is due to surface effects between the blade and whisker which seem to become significant at a scale of around 100 nanometers. Commercial manufacturers are able to economically reduce these effects by using coatings derived from platinum, chromium, teflon, and other proprietary coatings. We have no such luxury, so in order to approximate the sharpness of the feather we must approximate the effects of those coatings by other means.

Oh yeah, I concur that you've gotta fix that bevel before attempting to go further.

And you don't need a triple-bevel or even a double-bevel to get feather sharpness - the different angles in the bevel are there in order to simplify manufacturing. If you're building a honing line that is sharpening a mile-long ribbon of steel then you've got to make sure that the various honing stages can happen in the same amount of time while the ribbon is passing through. But a 30,000 grit wheel cuts much slower than a 4000 grit wheel, so you've got to make sure that it has less steel to remove.
 
Some great responses so far!

I have to go to an event now and won't be back till late tonight but I'll reply tonight or tomorrow.

Joe
 
Which is cool because you've already got spots reserved. Dang, the next time I get into a forum argument I'm going to reserve some spots ahead of time. :smile: Nice pictures though too. I think these threads really help people learn to hone.
 
It looks like to me that the razor had previously been honed. Who honed it or how it was honed appears to be different than your honing technique. To re-establish the bevel,I would start with circular patterns. Then use the marking pen and re-hone it.

Glen
 
Outstanding micrographs. Can't wait to see what the fine, ultrafine, and CrO scratch patterns look like with your setup..
 
Since you have been wise enough to reserve some slots...
I'm really looking forward to this.

I've gotten to the point where I can get what I would call a good but not great edge in the last couple of weeks.

I have read that a .25 micron paste can get you to the point of "too sharp".

I've got the norton 8k, a swaty and 3M .5 micron sheets at the moment and am waiting for a 12k chinese stone to arrive to fill the gap.

3M also makes a .3 micron honing sheet.
 
I spent a few hours last night working on the razor. I took a bunch of micrographs and will make a detailed post later tonight.

I'm really happy you all like the pics. They are a lot of fun to make and really help me get my head around what is going on.

The feedback you guys are providing is encouraging and very insightful! I hear you that feel is far more important than appearance. I will be shave testing the blade repeatedly. The goal is the feel of a Feather, the microscope just lets me see what the hone is doing and can give clues as to what needs to be done.

Replicating the lubricating coating on a commercial blade is a problem, but I do have some ideas. :wink: This might prove to be the one hurdle I can't clear.

I don't think the reason the Feather blades appear smooth is because of the coatings. If we assume they are polishing using a 30,000 grit(.4 micron) wheel then the scratches should be about .4 microns in size. As R. L. Moore noted in his paper "Comparative analysis of razor blade coatings using Auger electron spectroscopy", the typical coating is between 200-400 angstroms thick. I wouldn't think that is nearly enough to fill a .4 micron scratch but I am not well educated in these matters and perhaps am missing something.

As I mentioned in my original post, I do understand that the triple bevel is an artifact of the manufacturing process and I am not attempting to replicate it but I might experiment with micro bevels to speed the honing process.

I am familiar with Prof. Verhoeven's work and I have been in recent discussion with him regarding his findings about natural leather strops. I started a thread about it here. The magnification that I am using is not sufficient to directly image the cutting edge. It is sufficient to observe the gross features and differences between the blades. I feel that can be of tremendous help in guiding the process. If we can't even replicate what we can see at 200x then 3000x will be of no help.

Prof. Verhoeven compared a standard Gillette DE blade to a straight and found both to have an edge width of around .4 microns. He also noted that the straight razor had a rougher edge. Of course the American Gillette blade is widely considered to be one of the duller, more "forgiving" blades. Not in the same league as the Feather which is widely held to be the sharpest blade available by a good margin. As such I think we can only state that the straight he examined is as sharp as one of the less sharp DE blades. I personally won't shave with the Merkur, Gillette, Derby, etc. as they pull and scrape too much, much like my current straights. I only use Feather & Swedish Gillette's in my DE's. But I'm picky. :biggrin: or insane...

Joe
 
I spent a few hours last night working on the razor. I took a bunch of micrographs and will make a detailed post later tonight.

I'm really happy you all like the pics. They are a lot of fun to make and really help me get my head around what is going on.

The feedback you guys are providing is encouraging and very insightful! I hear you that feel is far more important than appearance. I will be shave testing the blade repeatedly. The goal is the feel of a Feather, the microscope just lets me see what the hone is doing and can give clues as to what needs to be done.

Replicating the lubricating coating on a commercial blade is a problem, but I do have some ideas. :wink: This might prove to be the one hurdle I can't clear.

I don't think the reason the Feather blades appear smooth is because of the coatings. If we assume they are polishing using a 30,000 grit(.4 micron) wheel then the scratches should be about .4 microns in size. As R. L. Moore noted in his paper "Comparative analysis of razor blade coatings using Auger electron spectroscopy", the typical coating is between 200-400 angstroms thick. I wouldn't think that is nearly enough to fill a .4 micron scratch but I am not well educated in these matters and perhaps am missing something.

As I mentioned in my original post, I do understand that the triple bevel is an artifact of the manufacturing process and I am not attempting to replicate it but I might experiment with micro bevels to speed the honing process.

I am familiar with Prof. Verhoeven's work and I have been in recent discussion with him regarding his findings about natural leather strops. I started a thread about it here. The magnification that I am using is not sufficient to directly image the cutting edge. It is sufficient to observe the gross features and differences between the blades. I feel that can be of tremendous help in guiding the process. If we can't even replicate what we can see at 200x then 3000x will be of no help.

Prof. Verhoeven compared a standard Gillette DE blade to a straight and found both to have an edge width of around .4 microns. He also noted that the straight razor had a rougher edge. Of course the American Gillette blade is widely considered to be one of the duller, more "forgiving" blades. Not in the same league as the Feather which is widely held to be the sharpest blade available by a good margin. As such I think we can only state that the straight he examined is as sharp as one of the less sharp DE blades. I personally won't shave with the Merkur, Gillette, Derby, etc. as they pull and scrape too much, much like my current straights. I only use Feather & Swedish Gillette's in my DE's. But I'm picky. :biggrin: or insane...

Joe
Joe,
From what I am told, Feather blades are laser sharpened - which is much finer than 30K :wink:
 
Lasers!!!

Are there sharks involved as well? :biggrin:

Well I don't have a laser sharpener at home so that might be a problem...

Joe
 
Should this thread be moved to the Hones/Honing sub-forum? Maybe some folks there will miss out and not see this.
 
Well I don't have a laser sharpener at home so that might be a problem...
The feather/laser line is an old joke around here. Lasers cut by heating the material at the focal point above the vaporization temperature, which which would coincidentally destroy the temper of the surrounding material that was heated to just below the vaporization point...

Feathers are polished with a fine grit abrasive, and I'm pretty sure the only real difference from the more prosaic blades is that Feather uses slower speed wheels and possibly a finer abrasive. Japanese have extremely thick, coarse hair and actually *need* the extra sharpness for a comfortable shave, whereas for western manufacturers such levels of finish are merely unnecessary expense. It is entirely possible that feather uses finer abrasives than the 0.4 micron mentioned earlier. There are much finer abrasives out there in industrial use. 0.25 is pretty common around here, and 0.1 micron diamond is readily available though less commonly used on these forums. I've got a syringe of it in my closet that cost me about $40; obviously it's much cheaper in bulk, and I'm not even sure that this is the finest grit available.
 
Last night I spent a few hours working with the razor. I first tried get a uniform bevel on the Spyderco medium hone. This did not work very well as it just removes metal too slowly. I decided to drop down to my lowest grit stone which is an 800 grit Japanese water stone. I lapped the stone flat and begun working on the blade. After about a half hour I had made some progress but the bevel was still not uniform. I think the problem is that the blade has a slight smile. I'm not sure how to correct a smile. It seems like one would just keep making passes on the hone until the middle of the blade wears down and catches up to the heel and toe. Even at 800 grit this was taking a long time. I decided to stop there and get a coarser hone. I figured I would at least work the blade as-is through the grits and see what it looks like while I wait for the other hone to arrive. Since the middle 2/3's of the blade has a good bevel we can at least use that portion to experiment with.

I proceeded to give the razor about 40 laps on the medium grit.

SG Med Grit 60x, Side Lighting


SG Med Grit 60x, Front Lighting


SG Med Grit 200x, Side Lighting


This shows a fairly rough edge, good bevel, no wire edge. I then gave it 50 on the fine.



SG Fine Grit 60x, Side Lighting


SG Fine Grit 60x, Front Lighting


SG Fine Grit 200x, Side Lighting


It seems that the scratch pattern is significantly finer, the edge has become much more smooth and even. The fine grit has definitely improved the edge. I then moved on to the Ultra Fine grit and gave it 60 laps.



SG Ultra Fine Grit 60x, Side Lighting


SG Ultra Fine Grit 60x, Front Lighting


SG Ultra Fine Grit 200x, Side Lighting



While there has been some improvement of the edge and polishing of the bevel, we don't see the dramatic difference that we did going from medium to fine. This lends support to the belief that the Spyderco Fine & Ultra Fine have the same abrasive particle size, just held in a different matrix and finished differently. I think an employee on the Spyderco forums stated that is the case. None the less, the edge is much smoother than when we started. The last step is stropping on CrO.

SG CrO 60x, Side Lighting


SG CrO 60x, Front Lighting


SG CrO 200x, Side Lighting


Again we see some improvement but not dramatic improvement. I think this is because we have jumped from 6-7 microns all the way down to .5 microns with out any intermediary steps. It might take a very long time for .5u CrO to polish out the scratches from a 7u stone.

Since I had gone this far I decided to shave with the blade this morning even though the heel and toe are not in equal shape. This is a bit of an unfair trial as shaving comfort can't be judged by a blade that is only 2/3's of the way there. None the less I went ahead. It was a pretty good shave, very little pulling from the middle of the blade but not in the same league as a Feather. This is to be expected given the equipment that I have and what others have said is required to hit the super sharp stage. The toe had a bit of scraping and pulling and that kind of masks how rough or smooth the well polished parts of the blade performs.

The next step is to get a uniform bevel across the length of the blade. I have a DiaSharp D8C on the way that should allow me to quickly reset the bevel. I also have some 12, 5, 1 & 0.3 micron abrasive film on the way. My plan is to get a uniform bevel on the D8C, move to the 800 grit water stone, then to the medium grit, fine grit, ultra fine grit, 5 micron, 1 micron & finally 0.3 micron film. I hope that will give a sharper edge. The Shapton 30,000 claims to be 0.49 micron so I think the 0.3 micron film may give similar results(at $3 vs $400).

Should be fun! :biggrin: Any suggestions or thoughts?

Joe
 
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