Thread: Downstroking to remove microchips

Has any forum member used the downstroking technique to remove microchips (observable under 450X magnifacation)? It appears the edge can be lightly "cut" against a glass jar or on the corner edge of a fine grit stone before rehoning the edge. It's counterintuitive to drag a sharpened edge against glass or a stone, so I'm hesitant to try it, especially since I gave this razor the shave test following sharpening and it did a great job.
Here's a description of the technique from WIKI :

"The easiest and gentlest way to dull a razor is to put it with the edge down on a glass jar and perform one, maybe two, cutting strokes without any significant pressure.
The technique can also be adapted to remove microchips. In that case the razor can be downstroked at the side of a very fine hone, till all the chips are gone. This calls for some sort of magnification device to inspect the edge. "

Yes I have. Do a forum search for breadknifing and you will find previous threads addressing the technique. Sometimes it is advisable to flat hone chips out. It depends on how bad the edge is to begin with.

I was talking with Lynn this weekend about microchipping, particularly in harder blades. I have noticed that under magnification, some of my razors occasionally show some microchipping. These are razors that are extremely sharp and not pulling at all. My observation is that the microchips appear in the final polishing stages of honing when I am using either a pasted flatbed hone (or strop) or a high grit hone. They may be the result of too much pressure and granularity in the extremely fine edge of the razor.

If you dull the razor against a jar or finishing hone (sort of a micro-breadknifing) you have to go back through the finishing stage again. Given that, I just go back to the finishing hones and proceed really slowly. I concentrate on not repeating my error, until the microchips are polished out. So, no jars for me, at least on chips that you need 450X mag. to observe (or even on the 100X visible micros). Maybe on bigger chips?

Originally Posted by dicharry

Has any forum member used the downstroking technique to remove microchips (observable under 450X magnifacation)?

Yer kidding right????

450X Everything has microchips at 450X

If it shaves well "your words" I would quit messing with it.....

Bill,
This razor as purchased had some significant but irregularly spaced chips in the blade- The kind that can appear as very faint dark spots when viewing the blade at the correct angle under a light source. After some significant time on a 600K, even with the circle stroke used for knives and tools, then moving up to a 1200K and going between the two until the big chips were removed, I could still observe a significant amount of microchips in the coarse sharpened blade under high (450X) magnification.
I moved to the 6000K japanese water stone in an attempt to remove the remaining microchips. Following this the blade was passing the TNT and TPT and arm hairs dropped off at the lighest touch. My mistake was not checking the blade under magnification at this stage. I moved to my Chinese 12K for a few strokes then on to a CrO2 pasted balsa board for about 25 strokes. Before putting the blade to the shave test I decided to examine it under 450X . Even though the edges were beautifully smooth, there were still several small microchips visible under high magnification.
I benchmark all my shave tests against my Lynn Abrams sharpened Silver Wing TI. This blade compared favorably againt the TI, so maybe the microchips are too small to make a significant shave difference ?

Gssixgun,
Your point is well taken. Maybe I've been making these edge observations at too high a power. Another thing I sould do is examine the TI under high magnification even though I cringe at the thought of bringing the high power turret so close to the edge of that Silver Wing.

Originally Posted by dicharry

. Before putting the blade to the shave test I decided to examine it under 450X . Even though the edges were beautifully smooth, there were still several small microchips visible under high magnification.

I don't typically use more than 100X, but I have noticed the same thing. Despite the microchips the razors shave extremely well. In fact, when I have decided to do nothing about the microchips (usual course of action) they seem to smooth out with ongoing stropping. All in all I find microchipping to be a pretty interesting topic, but I don't know how much they really affect the performance of an otherwise keen blade.

All I have is 30x. I sent a friend a razor I shaved with that was IME shave ready. He got back to me and told me that he had looked at it under 200x and it had micro chips. What will the neighbors think ? I had taken another look right before I sent it and the edge was as slick as a wall st. banker. I told my friend that if he doesn't go above 30x his honing would improve dramatically ....... not that his needs to improve.

"Downstroking" is a term I invented for writing that wiki article.

It's a technique I suggested as an aid for when a razor needs bevel correction work. The main idea is to dull the razor, just enough to make it duck all tests (TNT, TPT, shave arm hair test, etc...) This takes the guess work out of knowing when the new bevel is complete and when it becomes time to proceed to the rest of the honing progression. The glass jar trick works like a charm. After you dulled the razor with one gentle stroke, you simply stay on the bevel setting hone till the razor shaves arm hair again.

I don't think this applies to your current situation. At 450X, as Glen pointed out, it's pretty normal for some razors to have microchips. I think "dulling" is often no more than the accumulation of such microchips over number of shaves.

Breadknifing, which is very similar to "downstroking", yet performed on a hone with multiple "sawing" strokes, serves to remove steel that needs to go anyway, whether that is to remove a frown, corrosion, or to hone out larger chips.
I would not use it to remove something that is invisible to the naked eye. Those imperfections can easily be honed out with less drastic honing methods.

What you describe should be easily honed out with a few strokes on fine hone.

I never check with higher magnification than 40X, but my scope does have excellent optical resolution. I see more than what you can typically see on a Radio Shack "100X" scope, or on many low end USB-microscopes. In that respect, it's hard to have an idea about the exact size of your microchips.

Best regards,
Bart.

If it's shaving well, microchips are ignorable.

Holy Toledo! That's what I love about this forum. A response from the original arthor of the WIKI article- Bart. Thanks for that Bart. I'm convinced that I have been obsessing over something that means little since the ultimate test (the one that really counts) is the shave test, and this blade passed that with flying colors. Now I am going to have to go back to making some observations as to what is and is not significant when it comes to ultra-microchips. I am about to put this AO microscope on the side (which gives excellent images btw) in favor of a high quality stereo microscope with a 120X top end magnification. From what I see here, that should be more than adequate magnification. Would you believe I was considering a metallurgical inverted microscope ! I often let my obsessions get the best of me. In any case, I'm no doubt preaching to the choir since we all have the same straight razor "illness" if you know what I mean.
Don