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First time with lapping film

So, I was unhappy with *some* of my edges. What was irritating was the lack of reproducibility. same kit, same day, one edge would be great, the other 'meh'.
So I *could* have invested in $$$ worth of extra, different, stones. However I *also* would like to try out the convex hone-surface-school-church of honing, but of course I don't want to throw $$$ worth of stones at it...

So, the idea is, I'll get lapping films, and play with that, then I'm going to make myself a convex stand for it, and I can try that too, easily, without breaking the bank.

For the film proper, I have that lovely piece of stone, dead flat, very smooth. film sticks nicely to it, seems to have done a good job.

I'm very impressed with the quality of the edge I get straight out of the pink film! WAY smoother than my Norton 8K! And after the yellow film it's just perfect mirror. Seems dead easy. No lapping necessary. Just have to make sure theres a pool of water sloshing around that's all it needs it seems...

For the next convex experiment, I've for a 10mm plate of G10 that should be easy to sand to a shape, and polish, and the film ought to stick to that as well. we'll see!

So far I refreshed 3 blades, all look perfect, split hair-in-the-middle easily. I'll do a shave test tomorrow!

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rbscebu

Girls call me Makaluod
Well done. I am rather restricted in budget for whetstones so have also often relied upon lapping films for my edges.

After getting a great shaving edge from lapping films, I finish on diamond pasted balsa strops. Very occasionally I can get an edge keenness that meets or possibly slightly exceeds that of a Feather DE blade from my balsa.
 
Well for me, starting up, I don't *want* to buy stones if I don't have to, TBH... theres so many options, and so many pro-cons, so many qualities etc etc it's way more of a minefield than razors, and I'd rather buy razors :)

How 'far' will the lapping film lead me in terms of edge? I *think* (just by looking with the loupe) the edge I get are possibly 30% better 'looking' than my previous ones (on a chinese waterstone).. The balsa + abrasive look interesting, and right my alley in terms of 'reproducability' -- oh and also, price.
 
Well for me, starting up, I don't *want* to buy stones if I don't have to, TBH... theres so many options, and so many pro-cons, so many qualities etc etc it's way more of a minefield than razors, and I'd rather buy razors :)

How 'far' will the lapping film lead me in terms of edge? I *think* (just by looking with the loupe) the edge I get are possibly 30% better 'looking' than my previous ones (on a chinese waterstone).. The balsa + abrasive look interesting, and right my alley in terms of 'reproducability' -- oh and also, price.
Film and pasted balsa will get you an edge as sharp as you will ever need. The general consensus is that natural stones give an edge a little less sharp/keen, but more comfortable. I've only ever honed with film and pasted balsa so I have no direct knowledge of how they compare.

Film is nice because it's consistent and doesn't require any lapping to keep it flat. You can concentrate on learning to hone without worrying about slurries or whether an edge isn't turning out because of the stone or because of beginner technique. It didn't take me long to figure out that it's easy to hone a razor without any warp, twist, or weird spine wear. Most razors aren't like that though, and will take some honing gymnastics to get a proper edge from heel to toe. Film removes a lot of variables while you're learning.

And the price is right too.
 
“I'm very impressed with the quality of the edge I get straight out of the pink film! WAY smoother than my Norton 8K! And after the yellow film it's just perfect mirror. Seems dead easy. No lapping necessary. Just have to make sure theres a pool of water sloshing around that's all it needs it seems...”

Well, that is because, depending on the film maker, 3m, pink 1um film is about 12-16k, depending on which chart you look at. Probably twice as fine a an 8k. and Cream .5um 200 to 500K depending on maker’s claim.

“So far I refreshed 3 blades, all look perfect, split hair-in-the-middle easily. I'll do a shave test tomorrow!”

Yup, it is a good way to learn to refresh,

Long term results and cost savings depends on how many razors, you are honing, how often, the condition and if you are just touching up a razor that has been properly honed or restoring an eBay beater. You can burn through a single sheet on one razor.

Sharp is just one factor in razor honing, natural hones offer a wide range of keenness and… comfort. You can easily get too sharp.
Most guys that start with film, eventually switch to natural finishers, and synthetic stones for grunt work. It is cheaper and way more effective.

You can use both, bevel set on synthetic and finish on film. But still there are “better” shaving edges available.

Sharp is easy, enjoy.
 
I did some shaving with the 3 razors, and yes, very happy, pretty much as good or a notch better as what I've come to expect. I'm sure my expectation are far from what other people do achieve, but it's considerable improvement to what I had so, two thumbs up!
No tugging (unless it's under my neck against the grain, but heck, they all so, it's a tought area) and no irritation at all, according to Mr Alum.

So, what are my next step? pasted balsa for just that little bit more?
 
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I did some shaving with the 3 razors, and yes, very happy, pretty much as good or a notch better as what I've come to expect. I'm sure my expectation are far from what other people do achieve, but it's considerable improvement to what I had so, two thumbs up!
No tugging (unless it's under my neck against the grain, but heck, they all so, it's a tought area) and no irritation at all, according to Mr Alum.

So, what are my next step? pasted balsa for just that little bit more?
There is no harm in trying balsa. However, if the edge is smooth after the lapping film the balsa might not add much, if anything. You are effectively introducing more convexity to optimize the apex. In my opining, it is like chasing your own tail:)

If you look at the curve. The highest peak is around 40-50 micron. In this region the resistance is mostly driven by the bevel geometry. If you are able to create a smaller radius at the apex with balsa, you are mostly affecting the first part of the curve. You are also creating an edge that is less skin friendly. The "perfect" edge is the best compromise between a apex radius your skin can handle, while still being able to cut your beard with minimal tugging.

The geometry of the bevel behind the apex is just as important as the the radius at the apex.


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This is a smooth "pasted" edge. It passes the HHT fine and is popping arm hair. So why does it suck for me? The bevel has too much convexity from the soft substrate it was honed on.

IPC_2022-07-13.19.53.40.7980.jpg

This is the same edge where the convexity is replaced by a concave bevel. This gives a big difference in shaving performance. It is probably obvious from the first curve what role the geometry has.
No tape was used. Only a convex stone, followed by a flat finishing stone ( Coticule followed by Arkansas).
The apex radius is not smaller, but the thickness behind is thinner. Not by much, but more then enough.

IPC_2022-07-14.12.24.52.2350.jpg
 
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@JPO
You write " If you look at the curve. The highest peak is around 40-50 micron. In this region the resistance is mostly driven by the bevel geometry......The geometry of the bevel behind the apex is just as important as the the radius at the apex."
how do you interpret this curve to arrive at this conclusion?

I ask this question because on my side, With the same picture, I come to the conclusion : the geometry of the edge (the first 5µm) explain 95%.
It would be enriching to share our respective approaches.

My last question
Do you have a measurement or evaluation of the finished bevel part on flat stone in the second image?
Thanks
 
@JPO
You write " If you look at the curve. The highest peak is around 40-50 micron. In this region the resistance is mostly driven by the bevel geometry......The geometry of the bevel behind the apex is just as important as the the radius at the apex."
how do you interpret this curve to arrive at this conclusion?

I ask this question because on my side, With the same picture, I come to the conclusion : the geometry of the edge (the first 5µm) explain 95%.
It would be enriching to share our respective approaches.

My last question
Do you have a measurement or evaluation of the finished bevel part on flat stone in the second image?
Thanks
The included curve does not provide enough information to quantify this. It was probably not that relevant in this context. What we do know is that convexity created from using something like balsa changes the bevel angle quite allot, in this case the first 50 microns is important. The bevel angle changes the amount of energy required to complete the cut. If there was more information available one could brake it down into known factors and come to some sort of conclusion. You give up something in the pursuit of something else. It is a trade off.

I am not sure what you mean by evaluation of the last image. I took a razor with a convex bevel, that was not shaving at all. Improved the geometry without effecting the apex, and the razor shaved much better. There is allot of variables that play in here that is not easy to quantify.
 
Thanks for your reply @JPO
You are right it is just an exchange (very interesting and stimulating)

It's already a feat to find someone who accepts that the really determining part of the bevel is the first 50 µm all along the blade. This avoids chasing the gigantic shadow of the prey (the whole bevel) rather than the prey itself the first 50 µm (1mm = 1000µm)

With your last message I better understand your reasoning and your conclusion. I completely agree with you on the impact of convexification on these 50µm because it can change the angle of the edge a lot in this area and increase the energy to go through the hair. In your example between an edge that slices well or not, the difference is explained by geometry and more precisely by the convexification of the first, because you say that the apex (its thickness) has not been affected.

I totally agree with you that there are a lot of variables that are not easy to quantify and that's what I think is why we have slightly different assumptions about the contribution of the first-order factors.
Effortless cutting = apex thickness, convexification of 50 µm.
If you allow it I would add a factor at the apex which is the size and the number of micro-teeth. What makes me add this factor comes from this image of a shark tooth.
There I feel that I will end up burning on a log….

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Thanks for your reply @JPO
You are right it is just an exchange (very interesting and stimulating)

It's already a feat to find someone who accepts that the really determining part of the bevel is the first 50 µm all along the blade. This avoids chasing the gigantic shadow of the prey (the whole bevel) rather than the prey itself the first 50 µm (1mm = 1000µm)

With your last message I better understand your reasoning and your conclusion. I completely agree with you on the impact of convexification on these 50µm because it can change the angle of the edge a lot in this area and increase the energy to go through the hair. In your example between an edge that slices well or not, the difference is explained by geometry and more precisely by the convexification of the first, because you say that the apex (its thickness) has not been affected.

I totally agree with you that there are a lot of variables that are not easy to quantify and that's what I think is why we have slightly different assumptions about the contribution of the first-order factors.
Effortless cutting = apex thickness, convexification of 50 µm.
If you allow it I would add a factor at the apex which is the size and the number of micro-teeth. What makes me add this factor comes from this image of a shark tooth.
There I feel that I will end up burning on a log….

View attachment 1514208
Yes, the apex condition/teeth is also really important. It probably explains why different edges from naturel stones, like the coticule, can cut so well.
Different synthetic stones also leaves different footprints on the apex.
This could probably be covered better in a new post.
Here is one example. The Morihei synthetic stones cut the steel different then other stones from e.g. Naniwa. This stone is a mix of natural stone and synthetic.
This is a 1k edge. There is almost no deep striations along the bevel. There is also a completely different look to the apex. If this also happens all the way to my 12k Morihei, I think I know why this type of edge cuts better then a highly polished 12k Naniwa.
This stone is a little coarse in my
opinion, but it can give a indication.
Your shark teeth anologi seem quite relevant here.

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So, what are my next step? pasted balsa for just that little bit more?

While pasted balsa may improve performance beyond film, for my purposes diamond pasted balsa is primarily a convenient way to maintain and refresh a fading edge without setting up film or using my Naniwa S2 12k hone.

Daily, I strop on '200k' before linen and leather. When I decide it is needed, I do the 50k/100k/200k progression. Shave performance is my gold standard. I don't have a microscope or very many honing theories. My loupe is just useful for checking the bevel set.
 
While pasted balsa may improve performance beyond film, for my purposes diamond pasted balsa is primarily a convenient way to maintain and refresh a fading edge without setting up film or using my Naniwa S2 12k hone.

Daily, I strop on '200k' before linen and leather. When I decide it is needed, I do the 50k/100k/200k progression. Shave performance is my gold standard. I don't have a microscope or very many honing theories. My loupe is just useful for checking the bevel set.
Your face and a simple loupe is hard to beat:)
 
As you, the magnifying glass was enough for me to know if my reset is well finished and later to check that my edge will cut well or my. The microscope only serves me to understand Why and to identify the right factor. once you find the right reason you can use a lot of options to get there. Do you think disposable blade brands use natural stones and Cr3 O2 to hone their blades?
 
For the next convex experiment, I've for a 10mm plate of G10 that should be easy to sand to a shape, and polish, and the film ought to stick to that as well. we'll see!
It would be really interesting to see what you can do with this. The only problem is see is to get the film to fit over a curved surface. Is there any elasticity in these lapping films?
 
As you, the magnifying glass was enough for me to know if my reset is well finished and later to check that my edge will cut well or my. The microscope only serves me to understand Why and to identify the right factor. once you find the right reason you can use a lot of options to get there. Do you think disposable blade brands use natural stones and Cr3 O2 to hone their blades?
I have no idea how DE blades are honed.
I think these blades rely on the coating to a large extent. Once the coating wears off they are usually not that grate, in my opinion.
Palm stropping DE blades seems to help before the first use.
 
It would be really interesting to see what you can do with this. The only problem is see is to get the film to fit over a curved surface. Is there any elasticity in these lapping films?
well I assume on one axis it should be fine, if I don't make too much of a curve on the short axis, it might also work as it's a plastic film anyway, I DO assume it should flex up to a point. Only one way to find out :)
 
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Yea, no problem with film curving over the surface. Another good substrate is glass tile. Glass is easily sanded/flattened with 220.

I have the forms and may have to try and grind one when I have some time. I was going to convex a Kopa Jnat.

Film stick like glue to any smooth surface, just will not do compound curves, it is abrasive mounted to mylar.
 
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