What am I seeing through my loupe? Am I hallucinating rust?

[rhgg2]

I have a very specific question about loupe viewing which I can't really provide an image for, I'll just have to describe it.

If I place my straight flat on the table with a bright light source directly above and shining down, and look at the apex of the bevel through my Belomo 10x loupe, then by moving the blade and/or lens very slightly the mirrored surface switches between completely white and completely black. Somewhere in the middle there is some kind of penumbra effect, where the light just illuminates the edge but not the whole bevel.

If I do this at just the right angle, the image sort of separates in front of me, something like a double image, and the very apex becomes something extremely raggedy looking which is a deep rust red colour. In fact it looks like the very edge of the blade is incredibly rusty. Under normal lighting this is invisible either with the naked eye or with the loupe. The effect is independent of the colour of the background behind or under the blade.

If I do a full refresh with 3u->1u film this effect goes away, but it comes back again after a few days. This seems to correlate with the edge losing both keenness and smoothness, such that the refresh is actually necessary. (I maintain daily on .1u pasted balsa, but it loses acceptable sharpness after about 4-5 days).

I dry my blade very carefully and strop about 10 times immediately after shaving to dry the edge. So I'd be surprised if it actually was rust, unless my blade is incredibly prone to rusting. My other thought is that it is some kind of optical illusion which is, however, representative of the poor condition of my edge apex.

So, what do you think? Is this a known optical illusion (some kind of chromatic fringing)? Or is my blade just rusting merrily away?

 

[Herrenberg]

It's an interesting question, and I don't know the answer to it, but I have a guess, which is that I don't think you can trust what you see as being meaningful. Optics gets weird when you are dealing at the level where the wavelength of the light comes into play. And there's a reason why good microscopes do not use a single source of light, but instead use combined light from different angles. Maybe the red is some sort of prismatic effect?

 

[JPO]

I have seen this using my loupe as well. I have seen it during honing, so in my case it is not rust.
To me it is a sign that the apex is well formed. If you have any distraction at the edge you will probably not see it

I don't think the edge dropping off is related to what you see.

 

[rhgg2]

Thanks! I agree it seems like some kind of prismatic effect. I should try with light sources with different spectra and see what happens. In any case, great to know that others have also experienced this - at least it is one more cause I can rule out in the quest to make an edge that lasts me more than a week. In the meantime I get a bunch more honing practice...

 

[JPO]

(I maintain daily on .1u pasted balsa, but it loses acceptable sharpness after about 4-5 days).

That might actually be what is causing your issue. I would just see if there is a difference if you just maintain the edge with linen and leather. If the steel is of good quality it should last for a long time.
The balsa maintenance work for some people, but i never had any luck with it as a daily maintenance routine.
If you have a tough beard your edge gets beat up. A leather strop realigns most of it. When you maintain it on a soft substrate you are in some cases weakening, and convexing the edge.
It might help if you strop on leather before the balsa to level down some of the high spots in the edge from shaving.

I had the same experience using balsa as a daily maintenance routine.
During the tests i have done my second shave was quite good. My third shave usually felt a little rougher, but still quite good. At the forth shave the edge feels a little smoother, but is not cutting as well. On the fifth day it started tugging a little, but is still reasonably smooth. The edge has now probably reach a plateau. So, if you don't have a tough beard, this might be an acceptable level, and you could maintain it this way for a long time.

You can see this effect with a microscope.

 

[rhgg2]

During the tests i have done my second shave was quite good. My third shave usually felt a little rougher, but still quite good. At the forth shave the edge feels a little smoother, but is not cutting as well. On the fifth day it started tugging a little, but is still reasonably smooth. The edge has now probably reach a plateau. So, if you don't have a tough beard, this might be an acceptable level, and you could maintain it this way for a long time.

Very interesting, this is pretty much exactly my experience (my beard is pretty tough). Really good for two days, then going downhill in just the pattern you describe, while also getting a bit smoother. At the end it's kind of okay but as I only do wtg/xtg it's pretty obviously not as close. You can see the edge looking less straight day by day under the loupe.

I figured initially this was largely down to underdeveloped technique and surely that is still part of it. But I'm now at the point where I think it's time to stop doing the same thing and expecting different results. The 0.1u seems to be too gentle to offset what shaving does to my edge. At the moment I do 60 laps on the balsa then 60 on leather and I was actually already toying with the idea of going back to just regular stropping (and maybe chuck in a few more laps, as I think my stropping is still not yet totally effective). What you say confirms that this might be a good idea to try. Then maybe also try leather -> balsa and perhaps see what happens if I try super gentle laps on the 0.25u or 0.5u instead of the 0.1u.

 

[Mr Bedlington]

I have used the Belomo 10x loupe for years and I have honed hundreds and hundreds of razors, and never had one problem, it shows up everything I need to see.

 

[JPO]

I have used the Belomo 10x loupe for years and I have honed hundreds and hundreds of razors, and never had one problem, it shows up everything I need to see.

If you do a proper rehone every time, you don't need anything else.
If you want to see what is going on with the edge after touch-up's and the use of emulsions you need to look closer.

You don't need to see what is going on with the edge at high magnification either. If the edge feels off, the solution is always to rehone anyway.

 

[rhgg2]

Yes it is really good, very glad I got it. Learned a lot from the first couple of honing sessions I had after I got it. For someone without a well developed feel for when it's time to move to the next grit it's super useful to get some visual feedback. I feel like it's probably something the more you use it the less you need to use it, if you see what I mean.

 

[Kaldane]

Have a look at the spine in the same light - or keep the lighting and viewing angle the same and turn the razor the other way.

If you see what looks like a blue or purple border it's chromatic aberration.

 

[jason12768]

I dry my blade very carefully and strop about 10 times immediately after shaving to dry the edge. So I'd be surprised if it actually was rust, unless my blade is incredibly prone to rusting.

I don't know how many laps I do, but I always strop post-shave. I wanna feel the blade heat up to make sure the moisture is evaporated. I have some fine cotton I use for that, works flawlessly.
I also never use a loupe, it helps

 

[rhgg2]

Tried a touch up on the 3u -> 1u with no balsa involved. I definitely need some coarser film or a stone at this point, there are a few deep scratches ending at chips that I can't remove with the 3u.

Regardless, the first couple of shaves have been pretty good, like 95% of the sharpness I'd like. However I also tried stropping between passes (I usually do one wtg and one xtg) and am a little taken aback how much smoother and more efficient this makes the second pass. I guess this settles in the affirmative two questions: does my beard chew up the edge?, and, does my stropping do anything?

 

[JPO]

does my beard chew up the edge?, and, does my stropping do anything?

Stropping primarily realigns the edge. Shaving is rough on the edge, and can also cause microchips if the honing was not done right, or for a number of other reasons. The strop doesn't do much for these types of damages.
I strop between passes, and it does work quite well for me.

 

[rhgg2]

Stropping primarily realigns the edge. Shaving is rough on the edge, and can also cause microchips if the honing was not done right, or for a number of other reasons. The strop doesn't do much for these types of damages.

Indeed! I think my question was possibly a bit ambiguous, what I meant was, does MY stropping in particular do anything, rather than, does stropping do anything? Faced with a reality (slowly degrading edge) that diverges from the promise (edge stays the same), as a neophyte I will naturally suspect user error. One aspect of this could be that my stropping is extremely ineffective. But I think I have now ruled at least that out. I do like, for obvious reasons, your explanation that it's not really a user error kind of thing, in particular because of the corollary, which is that I should consider other ways of honing a blade to be sharp. (The honing is the part I think is the most fun)

 

[Gamma]

What you are describing sounds like an abberation, or distortion, possibly diffraction. Maybe combined. The type of light source, and angle of incidence can affect how you see what you see. I have my own way of viewing but when I have an edge with a finicky apex that is a little used, the dimensional change at that location/area/etc will change how light is being reflected. 'Rolling' the blade in the light path will reveal the issues. Just used this tactic for viewing today actually.

If you are doubting the efficacy of your stropping, try shaving without stropping. Then strop and see how it's going.
There are a few facets to what stropping does, and how to get there. If your stropping is only showing very minimal effects, maybe strop more, maybe use a slight bit more pressure. Maybe use a linen. Lots of options .

When I read about edges that need to be resharpened after 5 shaves I wonder why. If the steel is of good quality, and shaving technique is good, the a well done edge should be good for more shaves than that.

I'm not a fan of frequent use of sub-micron abrasives. I keep tester razors going on pastes but only maybe a few passes every 20-25 shaves or so. At a certain point I will zero the edge and start over. Those edges are usually honed to 5k or so before going to a compound.

 

[rhgg2]

I have my own way of viewing but when I have an edge with a finicky apex that is a little used, the dimensional change at that location/area/etc will change how light is being reflected.

Indeed I think I experienced this sort of thing. A very shallow ding on the bevel showed up under the loupe as a kind of floating coloured smudge.

If you are doubting the efficacy of your stropping, try shaving without stropping. Then strop and see how it's going.
There are a few facets to what stropping does, and how to get there. If your stropping is only showing very minimal effects, maybe strop more, maybe use a slight bit more pressure. Maybe use a linen. Lots of options .

Thanks. The part that has been trickiest for me is not pressure per se but distribution of pressure between edge and spine and in particular getting enough on the edge. A lot of this is to do with grip and how the flip works. After much experimentation I think I've now hit on something that does the job.

When I read about edges that need to be resharpened after 5 shaves I wonder why. If the steel is of good quality, and shaving technique is good, the a well done edge should be good for more shaves than that.

Yes this is what I had been starting to wonder too. Though I would not hazard to call my edge well done, it's certainly passable and surely should not deteriorate so fast. Apparently laying off the diamond paste has been a step in the right direction. After a full week of shaves since the last touch up the edge feels no less sharp, just a bit smoother.

 

[JPO]

Apparently laying off the diamond paste has been a step in the right direction. After a full week of shaves since the last touch up the edge feels no less sharp, just a bit smoother.

This also mirrors my experience. The linen is also mildly abrasive, and combined with a clean leather strop, should be able to maintain an edge for a long time. Shaving technique and beard prep also plays a big role, if the goal is to keep the edge going for as long as possible.
A good loupe is a really valuable tool when you learn how to use it's potential. You can really get allot of information out of a 10-15x loupe with a good field of view. I regret not buying a good loupe sooner.

 

[Gamma]

Though I would not hazard to call my edge well done, it's certainly passable and surely should not deteriorate so fast. Apparently laying off the diamond paste has been a step in the right direction. After a full week of shaves since the last touch up the edge feels no less sharp, just a bit smoother.

I am not a fan of diamond paste edges, especially poly diamond edges. Diamond edges never feel smooth to me, but mono is usually better for me in that regard. A shave or two will diminish the 'bite' but it never really goes away.

IME, the longer I go between 'touchups' of any kind, the better. Touching up daily or weekly seems to have a very short lived window of opportunity and after that point I need to re-hone.

 

[JPO]

I am not a fan of diamond paste edges, especially poly diamond edges. Diamond edges never feel smooth to me, but mono is usually better for me in that regard. A shave or two will diminish the 'bite' but it never really goes away.

IME, the longer I go between 'touchups' of any kind, the better. Touching up daily or weekly seems to have a very short lived window of opportunity and after that point I need to re-hone.

When I was considering buying a diamond spray I tried to find some good information about mono vs poly diamond. The closest I came was a youtube video, which seems to support that the mono diamond was preferable for this type of honing.

 

[Gamma]

Forever there was constant debate about this in the cutlery world, the idea being that Poly fractured better and this had a positive effect on sharpening. Most players there were not paying attention to the amount of pressure needed to fracture the crystals.

For razor finishing, there is, relatively, no pressure on the abrasive. So we are left with looking at the basic crystalline structure. Typically, our/my concern is 'feel' not stock removal. The concept of mono being smoother, for razors, was a typical known thing. When people wanted sub micron diamond though, mono wasn't all that available and the hive mentality decided to overlook known facts in favor of availability, cost, and profits.