Toothy edge after 8k

[TheBeast]

I wanted to ask if you ever experienced a bumpy, toothy edge when honing. I noticed my edge would be pretty good after 8k whetstone with 'working pressure', but it would get toothy after my finishing laps on that stone. Very light x strokes. Under the loupe, I could catch the light bounce off the very tiny edge. Under the scope, it looked like tiny chips. Some of them didn't even reach the edge. It was as if some steel got chewed out right before the edge and some of it ended Up like a full chip but others like a mini crater starting and ending right before the edge. No HHT and uncomfortable shave at this point.

I fixed it by not using light strokes on the 8k but finishing the Stone with 'working pressure', stropped, 75 laps 0.5um balsa, 100 laps 0.25um balsa. Much more straighter edge under the scope, way more comfortable shave, but still not quite there.

I wanted to get the edge super straight after the 8k Stone so that the Diamond balsa strops dont have to fix any previous errors, just boost the keenness/sharpness. But I had trouble with it...

The previous edge was my own with the same setup, about 50 shaves. I was refreshing it because I dinked the toe on the sink battery and created a tiny chip (went away quickly on the 8k)

Custom River Razors 7/8 in Near wedge Made from 1.2510 steel with approx 62.5 HRC hardness.
Shapton Pro 8000
Vintage flax linen and cowhide strops
DIY balsa strops with whatever paste I found online locally

 

[Christian1212]

Usually on the 8k I am just doing weight of the blade. Also has your stone been flattened?

I think you are honing on a stone that is not flat. The "working pressure" I think is slightly bending the bevel to match the stone surface. When doing the light weight passes the edge is possibly chipping from the tiny hills and valleys in the stone.

 

[lightfoot]

Not all 8K stones are created equal. If my Naniwa Snow White wasn’t so cracked I would be using that instead of anything else but I’ve just been going to a Nakayama with Botan after 5K lately. Seems like I’m not dealing with the post-5K synthetic liability since I’ve switched…

 

[Steve56]

Sounds like the steel isn’t holding the edge at higher grits. Try adding tape to the spine one layer at a time as a diagnostic test. If it isn’t holding a straight, even edge at 3 layers, something else is going on.

 

[TheBeast]

All my stones are checked with a certified straight edge and lightly lapped with Atoma 400.

The razor is a Near wedge, no way it gets bent, my 'working pressure' is just a little push with my fingertips, so that I Can hone a little faster. The finishing light laps are 100% concentration and slow.

I Also tried my Naniwa super stones, 8k and 12k. It was a bit better, but still not great.

When I first got the razor, it had a killer 0.25um Diamond paste and hard ark edge. After a few months, I put on a Nani 12k SS edge, no problem. Another few months, 8k Shapton Pro and 0.25 Diamond on balsa, no problem. But this time around, killed the edge twice and re-done it, to no avail.

Always honed with a layer of tape, because that was how the maker of the razor put on the first edge. I liked it that way so I kept it that way.

 

[psfred]

I would smooth the finer stones with some sort of "nagura" -- a hard stone of some sort, should be flat but doesn't need to be large. A wide chisel back or a heavy knife will work as well, raise some slurry if the stone is soft enough, you want to burnish the stone prefectly smooth so that only the actual grit embedded in the binder is doing anything.

An Atoma 400 will leave scratches in the finer stones and that can damage an edge. I never use a stone directly after a diamond plate if it's finer that 1K, too much risk of a rough surface. A very hard razor edge can chip on those scratches -- or more accurately, the bumps of stone between the scratches. Any stone finer than 1k should feel very smooth to your fingers if you are honing a razor on it.

Also, finishing doesn't take many passes, the hard work is done by the bevel setter and the next stone up, 3 or 6k. No need for more than very light pressure either.

If you see microchips in the edge, you will need to drop back to a bevel setter (nothing any more coarse) and re-establish a clean bevel. On that razor it may take a while, it's pretty hard! Once you have a clean bevel, the other stones are just polishing and refining the edge, very light pressure and a minimum number of strokes to remove the previous grit range scratches are all you need.

 

[Waistgunner]

Maybe you should try and bread knife the edge and start over. To me, it sounds like the steel is the issue, not your stones.

 

[H Brad Boonshaft]

If you are not experiencing this issue with other razors, the issue is with the razor and not your stone or stone’s flat or aggressiveness.

Edge impact damage often goes much deeper that what we see at the edge, especially with hard razors, which are more brittle and likely to chip with edge impact damage.

Likely that you did/have not removed enough steel to get to good solid steel. But it is not a big deal, how much you need to remove is dependent on the damage. Edge impact especially on a round object will radiate in a 180-degree arc as opposed to straight down below the chip, so the damage area can be much larger that the size of the chip.

Simply joint the edge straight and reset the edge, if it continues to chip or look fuzzy, (Micro-chip) joint it again or drop down in grit to a 4-6k stone to remove a bit more steel.

When removing a chip, I drop down in stone grit, more that for a refresh and often do a full 1k bevel reset to get to good steel.

 

[Gamma]

No matter what edge or what stone, there are always 'teeth' at the apex.
Honing is scratching steel. Those scratches terminate at the apex and create a cross-hatch pattern and depending on the magnification, teeth can/will be visible. With successively finer grits, in theory, the 'teeth' get smaller, finer, and closer together.

When any given so-called '8k' edge is said to be too 'toothy' - it is important to know what that claim is relative to. The 5k? Another 8k? Someone else's 8k? Someone sent me a photo of their 8k edge and it looks more like a 3k to me. So it's hard for anyone to say, definitively, what's what.

The rest of what is being described sounds like to me, as though the early work wasn't completed completely cleanly. Or there is some sort of problem revolving around excessive pressure or maybe the bevel was initiated on a diamond plate and not cleaned up well.

Occasionally I will jump from 1k to 8k to see what is going on. The resulting polish on top of the striation 'peaks' can, in many cases, reveal things that might otherwise pass unnoticed. If there is a 'rotten steel' component, it will be seen here easily.

Typically, for me, 8k work is short, maybe 20-25-ish laps with a very light touch. Minimal swarf on the first few passes after the previous lower-grit stone. Zero dark streaks on the stone. If the previous stone was a 5k, the 8k polish has a bit more mirror' to it, the apex is a smooth continuous line without deviation, and there are no fail points from coarse striations in the bevel.

I don't hone with a microscope, never did. I usually use a 4x loupe when I doubt something but that's more of an exception, not the rule. The issues I am talking about above is always felt easily in the feedback when honing. And when it's cleared out of the way then that is felt also.

If I was having the volume of issues with an edge as described above, I'd just put it on a 1k and make a 100% clean bevel and I'd pay max attention to the progress that follows. Easy peasy and removes all doubt. Should take only a few minutes if the original bevel's angle was on-point.

 

[lightfoot]

Typically, for me, 8k work is short, maybe 20-25-ish laps with a very light touch. Minimal swarf on the first few passes after the previous lower-grit stone. Zero dark streaks on the stone. If the previous stone was a 5k, the 8k polish has a bit more mirror' to it, the apex is a smooth continuous line without deviation, and there are no fail points from coarse striations in the bevel.

This took me a while to grasp.

A little more mirror is the way to go. The temptation can be to chase too much mirror at this stage and that comes with its own liabilities…

 

[Gamma]

In and of itself, a mirrored bevel looks nice but tells us nothing about the apex.
Plenty of mirrored beveled edges shave poorly.
Plenty of hazy messy looking bevels shave great.
For me, spending time and/or using pressure on an 8k is a no-go.
But without solid ground work the 8k work is sorta pointless.
It's not wise to build a house on a half arsed foundation.

 

[TheBeast]

Thank you for your insights.

I forgot to snap the scope pics because I only started thinking about the whole issue after I got the edge somewhere in the 'good enough for me' region. But with my weak "microscope" I produced far straighter edges, even with 1k. Under the scope these were pronounced little chips. Under the loupe they were the tiniest blips of reflected light, under the right angle. Even after jointing and bringing it back on the 8k once. Not enough experience in my hands to feel them though - thats why the "microscope".

It's a bit deeper than I initially thought it was. Now I thought about it a little more, I was Once before dropping to a 1.5k on this razor, that might be why it was so easy to hone to finish and refresh no problem.

I was thinking I would cheat the system, save myself some hassle, hone out the chip on the 8k - took about 5 minutes. Turns out I created more work.

I will remember to drop down to a bevel setter for anything more than a quick refresh. Maybe even refresh from bevel set, to keep practicing it. I was thinking too much about wasting steel on such a razor. On my practice razor, if I'm not where I want to be at 8k, I just drop back to 1.5k and start over cause I don't care for those razors. But I don't have enough experience to be thinking about wasting the minimal amount of steel on a razor, to make it last a lifetime. It would probably be more efficient to just learn as much as I can and worst case, buy a new one in a few years...

 

[JPO]

I was thinking too much about wasting steel on such a razor.

If you are careful with the pressure, and just do a minimum amount of strokes, you will not remove allot of material with a 1.5k.
I would rather do just a few laps on a coarse stone then spend allot of time on a higher grit stone. I typically drop down to 3k for most refreshments, if I use synthetics.
The edge gets beat up in use. This causes plastic deformation, which you are not able to realign with the strop 100%. This fatigued steel needs to com off to get to good steel. The easiest way to achieve this is with a slightly coarser stone. If you do the refresh before it's too late you might get by starting at 8k. I am typically not able to do that even after just a few shaves. If I try to do allot of work on an 8k, my edge just falls apart.

 

[TheBeast]

Just for reference, here is what I was talking about. This should be 0.1um paste on balsa, but I'm not sure... the paste feels wrong, it's from ebay. Flax 20 laps, leather 100 laps, wipe with a microfiber to get rid of oil for the pictures.

So in the top of the picture, I can see some weird things going on. I can pick that out with just a loupe, by twisting the razor in some good light. The shaving at this point is... meh. I'm by no means an expert on honing or shaving or evaluating the comfort or performance of the edge. This edge will cut HHT (holding the root end), will shave me close, but it doesn't feel right. It's not unusable, but it clearly is far from a solid one.

This weekend I will most probably start over from 1.5k, very lightly. Probably will follow with 5k and 8k. Consistent light touch on all the stones, keep it very short on higher grits.

 

[SliceOfLife]

Some of them didn't even reach the edge. It was as if some steel got chewed out right before the edge and some of it ended Up like a full chip but others like a mini crater starting and ending right before the edge.

This is razor pitting creating microchips.


As you thin the edge, pitting that the scratch pattern from your hones obscures becomes significant enough it literally goes from one side of the bevel to the other... creating chips if it's near enough the edge... bullet holes in the bevel if it's further back.

This is like 99.9% of the advantage of having a good scope when you are restoring eBay specials; is to easily see this stuff before you waste a lot of time "finishing". Without a scope; I would pretty much always grind an eBay special back a significant amount to get past this kind of pitting. A scope lets you see if that's necessary or not.

Since it sounds like a modern razor; I'd be curious how it got pitted... But what you describe is explained by nothing other than pitting that I've ever seen on a razor.

Maybe some guys who know more about smithing/metallurgy could explain it via carbide ripout or something... but I've never seen anything like that on any vintage razors (or gold dollars).


All that said, the image above isn't anywhere near high enough mag to pick out what you describe. At this mag, you're gonna mostly be seeing digital artifacting (assuming digital scope and/or camera) or grit that your wiping didn't get off the razor... not actual pitting or bevel holes.

 

[TheBeast]

All that said, the image above isn't anywhere near high enough mag to pick out what you describe. At this mag, you're gonna mostly be seeing digital artifacting (assuming digital scope and/or camera) or grit that your wiping didn't get off the razor... not actual pitting or bevel holes.

No pitting on this razor, it's 6 months old and used 3x a week.

It's actually super visible. I may have done a bad job describing it because I lack the vocabulary. I'm talking about that unevnnes on the very edge, which is reflecting the light and that's what's making it so visible.

 

[TheBeast]

Here is an attempt for a before and after shot. I went back to 1.5k, spent a few minutes on the 5k, until I was thinking I have removed all previous stria. Then 25 laps on 8k. Feels a lot straighjter with no strange reflections

 

[SliceOfLife]

You mean just the line of the edge?

That doesn't look that bad for an 8k synth edge to my eyes.

Image on the left, hard to be sure; but I'd guess maybe a foil edge there creating that bright spot... burr from the other side folded over and not broken off.

If you stropped @ the stage on the left; does it go away?

 

[LJS]

Just for reference, here is what I was talking about.

I see your picture and it simply looks like your bevel is not set. It is not a straight line and it is blunted. I would remain at 1000 for a while until the edge was right personally.

 

[H Brad Boonshaft]

If you load the photo in a photo editor, (I use MS Photo) and enlarge you can get a much better look at the edge.

After looking at your latest photo it does not appear to be edge damage, It looks like a rolled edge. Likely something that would clean up easily by jointing and re-setting the bevel on a clean 8k.

There is no downside to using magnification, it is especially useful for documentation of an issue, for reference or to get a better view and understanding of what is happening at the edge.

If you remove a lot of steel to remove a chip, it is not unusual to create a burr, especially if you are doing a lot of laps on one side at a time and/or using a lot of pressure.

Alternating finish X laps will generally, flex the burr enough that it will abrade cleanly as opposed to just breaking off and leaving a ragged edge.

If the burr does break off and leaves a ragged edge, joint and reset or simply hone with X laps to cut a new edge, the bevels are already flat so not much steel will need to be removed.

Joint it and re-set with X laps on a clean 8k.

Here is your photo of the edge, doubled in magnification.