Lapping Film: Trouble with the Finishing Steps

Dear B&B,

I have been a long-time lurker on this forum ever since I started DE shaving five years ago.

This past June, I picked a NOS Giesen and Forsthoff Adoration 295 straight razor, a poor man's strop kit from Larry, and a set of lapping film (30u diamond, 12u , 9u AlO, 5u AlO, 3u AlO, 1u AlO, and 0.3u AlO).

Diamond film from Nanolap Tech.

Aluminum oxide (AlO) film from 3M (the non-PSA backed variety)

I set the bevel on the 30u and then completed a progression from 12u-->5u-->3u-->1u-->0.3u CrO on balsa-->0.1u FeO on balsa-->plain leather hanging strop. This gave me an edge that was moderately sharp (HHT 3.5-4.0 though definitely no Feather) that worked well enough (albeit a bit harsh for my liking).

When using the films, I didn't really count my strokes. I mostly focused on feedback to let me know when a grit was complete (i.e. "suction" effect and water undercutting). This usually meant about 30-60 laps on each respective film. On the balsa, I used about 20 round trip strokes for each grit. This was followed by 40 laps on plain leather.

My problem is this: whenever I attempt to use the 1u film with picopaper underneath, my edge suffers greatly in sharpness.

I just barely dampen the copy paper with a moist paper towel. I apply the paper onto a dry piece of marble tile followed by slightly damp film. I make sure that no water gets underneath the film while I hone. I usually need about 30 laps on the 1u film (with picopaper in place) until I get a strong suctioning effect.

What am I doing wrong? Why is my edge degrading/less-than-satisfying?

I hone with minimal pressure (especially when finishing) using long, smooth x-strokes (varying the angle of the razor as I go).

I don't think it's a bevel-set issue as the razor lopped arm hair after both the 30u and 12u films across the entire length...

Thank you so much to this wonderful community for all that you have taught me in these five years!!!

I don't know anything about films, but welcome to B&B!

Thank you, sir!

I had found that I liked fewer laps,(like~6), on 1um over printer paper than what others were using. The last time I used about 6 laps on 1um over glossy newsprint, which is thinner and less compressible than printer paper, with good results. YMMV

I will give it a try. Thank you!

Do you see sharpness improvements after 6 laps? Or does sharpness remain at the baseline 1u level?

bluesman 7 said:

I had found that I liked fewer laps,(like~6), on 1um over printer paper than what others were using. The last time I used about 6 laps on 1um over glossy newsprint, which is thinner and less compressible than printer paper, with good results. YMMV

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LeBourbon said:

I will give it a try. Thank you!

Do you see sharpness improvements after 6 laps? Or does sharpness remain at the baseline 1u level?

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I think of the laps over paper as a refinement, or smoothing, of the edge, removing any light tooth and harshness more than sharpening.

I was operating under the impression that the finish over paper was supposed to add to the sharpness of the blade.

At least that's what Slash said here...

bluesman 7 said:

I think of the laps over paper as a refinement, or smoothing, of the edge, removing any light tooth and harshness more than sharpening.

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There are some scanning electron images of razor's edges posted by a gentleman using the name Fuzzy Chops. You should be able to find them in a search. The gist of what he found using lapping film over paper was that it created a slight radius at the blade's edge and increased the included angle of the blade edge. He surmised that this helped to eliminate the foil edge and make a stronger edge all at the same time. His images and reasoning do combine to make perfect sense I think.

Brian

LeBourbon said:

I was operating under the impression that the finish over paper was supposed to add to the sharpness of the blade.

At least that's what Slash said here...

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Brian,

Is this the photostream that you were referring to? https://www.flickr.com/photos/nanofab/sets/

Seems like Fuzzy Chops took it offline.

Based on what you're saying, lapping film over picopaper should only be used to de-burr the edge, right?

If that the case, then it makes sense that many laps would be problematic.

On the other hand, why do Slash and Seraphim recommend a substantial number of laps with the paper underneath?

BDF said:

There are some scanning electron images of razor's edges posted by a gentleman using the name Fuzzy Chops. You should be able to find them in a search. The gist of what he found using lapping film over paper was that it created a slight radius at the blade's edge and increased the included angle of the blade edge. He surmised that this helped to eliminate the foil edge and make a stronger edge all at the same time. His images and reasoning do combine to make perfect sense I think.

Brian

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LeBourbon said:

On the other hand, why do Slash and Seraphim recommend a substantial number of laps with the paper underneath?

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Because that's what they found works for them. I've found what works for me. Now you need to find what works for you. I think subtle differences in honing technique make an exact recipe at the finishing stage elusive. I go from the 1um over glossy newsprint directly to clean hemp and leather strops.

I just had another thought. When you said "My problem is this: whenever I attempt to use the 1u film with picopaper underneath, my edge suffers greatly in sharpness." How did you determine the set back at this point? If it was by HHT, you might be getting fooled by a toothy edge reading better on HHT before the pico-paper stage removed the tooth.

When I use paper under film, I full wet it out. Get the paper soaking wet. Then lay it out flat on the granite plate (or what have you), put the film down on that, give it a quick squeegee with the edge of my hand, and then hone away.

Perhaps if your paper isn't wet enough, the film isn't staying "suctioned " down well enough, and this is causing it to rise up in front of the edge while honing, creating a bevel angle that is way too steep for effective cutting/shaving?

Go back a few got levels to correct the edge and then try finishing with soaking wet paper underneath.

I always wondered if wet paper under film doesn't effect the edge so much as a result of the angle change, as because it allows the film a degree of give, so undetectable rocking of the razor on the surface of the film when attempting low-pressure passes compresses the paper, rather than honing a wave into the bevel, creating a foil edge.

SliceOfLife said:

... so undetectable rocking of the razor on the surface of the film when attempting low-pressure passes compresses the paper, rather than honing a wave into the bevel, creating a foil edge.

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English is my first language, but I don't understand what you mean.

Since you're not exerting heavy downward pressure on the razor, the limits of how steady ones hands are will be tested. At extremely high grits like this, a wobbling effect from this (which is too minute for us to notice) causes the extreme of the edge to flex up and down at points as it moves along on the hone, creating a ripple-shaped foil edge (exactly like we saw in Fuzzy's SEM images of a paper-less Film edge). At lower and less regular grits, as well as on softer stones and slurried stones this is less of an issue unless you are having exaggerated movement on the hones, as this edge will be sheered off before it will flex. This seems to me far more likely to explain the way this solves the foil edges people are experiencing, rather than the fraction of a degree increase in final angle.

I determine the setback based on the floating-over-the-arm-hair test. The razor barely lops off hairs after the picopaper treatment.

bluesman 7 said:

Because that's what they found works for them. I've found what works for me. Now you need to find what works for you. I think subtle differences in honing technique make an exact recipe at the finishing stage elusive. I go from the 1um over glossy newsprint directly to clean hemp and leather strops.

I just had another thought. When you said "My problem is this: whenever I attempt to use the 1u film with picopaper underneath, my edge suffers greatly in sharpness." How did you determine the set back at this point? If it was by HHT, you might be getting fooled by a toothy edge reading better on HHT before the pico-paper stage removed the tooth.

Click to expand...

Thank you for the suggestions, Seraphim.

I will go and re-hone the razor starting from 3u and onwards.

Should the razor be as sharp as a Feather DE blade coming from the 1u film? If that's the case, then I'm definitely nowhere near that level of sharpness.

Seraphim said:

When I use paper under film, I full wet it out. Get the paper soaking wet. Then lay it out flat on the granite plate (or what have you), put the film down on that, give it a quick squeegee with the edge of my hand, and then hone away.

Perhaps if your paper isn't wet enough, the film isn't staying "suctioned " down well enough, and this is causing it to rise up in front of the edge while honing, creating a bevel angle that is way too steep for effective cutting/shaving?

Go back a few got levels to correct the edge and then try finishing with soaking wet paper underneath.

Click to expand...

SliceOfLife,

Do you have links to Fuzzy's pics? I haven't been able to locate them despite having seen them in the not-so-distant past.

Thank you!

SliceOfLife said:

Since you're not exerting heavy downward pressure on the razor, the limits of how steady ones hands are will be tested. At extremely high grits like this, a wobbling effect from this (which is too minute for us to notice) causes the extreme of the edge to flex up and down at points as it moves along on the hone, creating a ripple-shaped foil edge (exactly like we saw in Fuzzy's SEM images of a paper-less Film edge). At lower and less regular grits, as well as on softer stones and slurried stones this is less of an issue unless you are having exaggerated movement on the hones, as this edge will be sheered off before it will flex. This seems to me far more likely to explain the way this solves the foil edges people are experiencing, rather than the fraction of a degree increase in final angle.

Click to expand...

I don't think it is possible to get a straight razor as sharp as a Feather DE blade, but that's just me. I don't think I would want not what sharp either. I guess that why I am find of a coticule edge.

Post 16 in here:

http://badgerandblade.com/vb/showth...icroscopic-Scratch-Depth?highlight=microscope

Yeah, that looks like the place where the images used to live. The Internet is fickle....

I do not think 0.3 micron abrasive is really de- burring anything as there should be no burr when getting to the point (no pun untended) where that level of abrasive is useful. Proper honing should have eliminated any burr, if there ever was one, long before getting to anything that fine IME.

What the S.E.M. images showed was a "V" edge formed by two very flat planes before honing with paper under film. After the paper and film, the sides of the bevel were no longer flat planes but slightly beveled and the angle right at the razor's edge was significantly increased- something like from 15 degrees to 18 or 19 degrees going entirely by memory. That leaves a stronger edge that is far less susceptible to having a foil edge. So if that is what using paper under film creates, then the number of laps would not be important and really a LOT of laps could be used- it would just push the bevel and the edge back as you continued to hone. But with film that fine, the edge isn't going to be moved much with 1,000 laps so I don't think you could really overdo that part of honing.

The only problem with that beveling and increased angle is how to 'touch that razor up' later on. How many laps to restore the edge? If you go back to, say, 1.0 micron film and no paper, the two edge planes must be honed away until they again reach the razor's edge, and the bevel put back on with the finer film with paper under it. Nothing wrong with any of that, I just think it may require more steel be removed to maintain the razor over time.

Brian

LeBourbon said:

Brian,

Is this the photostream that you were referring to? https://www.flickr.com/photos/nanofab/sets/

Seems like Fuzzy Chops took it offline.

Based on what you're saying, lapping film over picopaper should only be used to de-burr the edge, right?

If that the case, then it makes sense that many laps would be problematic.

On the other hand, why do Slash and Seraphim recommend a substantial number of laps with the paper underneath?

Click to expand...