Stropping

[SliceOfLife]

Ok, I actually HAD some 6lb test in the garage. 0.23mm

It's bigger than the test media, but fits. I'm thinking heavier test would be better though, as it's getting REALLY low results (One of my razors passes @ 9grams). Might try to find some 25lb test or something along those lines.

On the 6lb line:
1200 grit finish ~14.5* razor stropped @ 148g.
8000 grit finish ~14.5* razor stropped @ 108g.


Aaaand... fishing line chips them too.


Any idea's?

 

[RayClem]

I got the PT50A, but the media is the same between all three anyway. The difference is which media/fixtures are included (all 3 can use all both, but you must buy one or the other aftermarket for the B and C, the A comes with both). I only used the spool so far, but I believe the clips are the same media, it's just preloaded and at a consistent tension.

I don't saw on the device... you can't really because you have the blade in the gelatinous pivot-holder. Sawing would destroy that. I was saying I had to saw with my teeth to get through the media... meaning it's probably WAY too durable for testing a shaving razor (try biting though a piece of hair, it isn't hard).



I've bought light monofilament fishing line to try that. It'll be here tomorrow. Until then I might actually see if my hair is long enough to get into both clips and use that just to get practice with it. Edit: Hair is probably a no go... not strong enough for the tension screws. I think the lightest possible monofiliment fishing line is gonna be our answer.

I posted a picture in the other thread of the chips. These aren't little chips. On all but one razor they are pretty easy to see naked eye... ~1/5-1/4 the bevel deep. These are SERIOUS chips. This media is NOT suitable for a straight razor.

I know the guy on the RefinedShave.com web site tested DE razor blades. I presume he used the media that same with the device and was getting values from 32 grams up to 69 grams. I know that DE blades have a less acute bevel angle (somewhere around 20-22 degrees, if I remember correctly) whereas straight razors are typically in the 15-18 degree range. I believe Gold Dollar razor bevel angles are in a range similar to DE blades, so perhaps they would be the best test subjects to start. Damaging the edge of a GD would not be as tragic as damaging one of your best razors. The refinedshave tests tests ranged from a low of 32 on a new Feather blades to as high as 69 on a used Treat carbon blade.

 

[SliceOfLife]

I know the guy on the RefinedShave.com web site tested DE razor blades. I presume he used the media that same with the device and was getting values from 32 grams up to . I know that DE blades have a less acute bevel angle (somewhere around 20-22 degrees, if I remember correctly) whereas straight razors are typically in the 15-18 degree range. I believe Gold Dollar razor bevel angles are in a range similar to DE blades, so perhaps they would be the best test subjects to start. Damaging the edge of a GD would not be as tragic as damaging one of your best razors. The refinedshave tests tests ranged from a low of 32 on a new Feather blades to as high as 69 on a used Treat carbon blade.

Manufacturer responded to my email asking about other media options saying what I’m seeing is from a rounding of the edge. Thinking maybe it’s an issue of either the fulcrum having too much space for a hollow razor (lets it hit the media @ an angle) or my trying to go too slow rattling the edge around in the middle of the media. Hopefully I’ll have time tomorrow night to test a bit more thoroughly and see if I can’t resolve this. Thinking about a brace in the fulcrum to hold the razor tight (the way it would a thick knife). That should resolve both issues

 

[Chan Eil Whiskers]

Ok, I actually HAD some 6lb test in the garage. 0.23mm

It's bigger than the test media, but fits. I'm thinking heavier test would be better though, as it's getting REALLY low results (One of my razors passes @ 9grams). Might try to find some 25lb test or something along those lines.

On the 6lb line:
1200 grit finish ~14.5* razor stropped @ 148g.
8000 grit finish ~14.5* razor stropped @ 108g.


Aaaand... fishing line chips them too.


Any idea's?

Yes.

One of us should get in touch with Sharpening Supplies (or whatever vendor we used) and/or the folks at Edge On Up. Since I typed that sentence I've sent the following email to Edge On Up.

Good afternoon,

I have just received one of your testers, the PT50A, which I ordered from Sharpening Supplies.

Several of my friends on the Badger and Blade forum have also ordered the instrument. However, one of them has today reported on the forum that the test media is consistently producing chips in the edges of his straight razors.

I am bringing this to your attention for obvious reasons and also to find out what you think we might do to allow us to use the devices we've purchased to determine the sharpness of our razors?

Is there another media option, or what?

I'm going to hold off on using my instrument on my straight razors (which I bought it to test) while awaiting your response.

Thank you in advance.

Sincerely,

Jim

I'll let you know when I know more.

Obviously, this is a problem.

Happy shaves,

Jim

 

[RayClem]

Manufacturer responded to my email asking about other media options saying what I’m seeing is from a rounding of the edge. Thinking maybe it’s an issue of either the fulcrum having too much space for a hollow razor (lets it hit the media @ an angle) or my trying to go too slow rattling the edge around in the middle of the media. Hopefully I’ll have time tomorrow night to test a bit more thoroughly and see if I can’t resolve this. Thinking about a brace in the fulcrum to hold the razor tight (the way it would a thick knife). That should resolve both issues

I hope you can figure it out, for your sake and for others on the forum. I have a high degree of scientific curiosity and am toying with the idea of purchasing one of the testers. The problem with using a non standard media is that you cannot compare your test results with those of others, although internal comparisons of one edge to another would still be valid.

 

[stone and strop]

I would think thread ( a large spool) would be best, then based on DE blades for comparative purposes.
It doesn't have to be a tough medium. If the numbers are low with DE' they are comparable to "known" sharpness.

 

[RayClem]

I had another thought since some folks were saying the were getting extremely low test values. Even those of us who typically shave with straight razors generally have a few DE or SE blades in our dens. If you have some DE blades, test them and see how your results compare to those of refinedshave.com for similar blades. Perhaps those who are getting extremely low test values are honing their edges such that they are extremely sharp. If you are using high grit hones or pasted strops, you may well be achieving that level.

 

[RumpleBearskin]

Silly question, but should someone try to duplicate the prior DE results to verify them, develop appropriate technique on the apparatus, and verify that the media performs as was originally anticipated?

 

[RayClem]

Silly question, but should someone try to duplicate the prior DE results to verify them, develop appropriate technique on the apparatus, and verify that the media performs as was originally anticipated?

I worked in the paper industry. There were industry standards for many paper properties. There were industry standards for testing methods and equipment. The way we confirmed the validity of our testing was to do round-robin tests were similar samples were sent to a variety of labs for testing. Then all the results were compared to make sure each lab was within range. Thus, duplicating prior results seems to be a reasonable idea.

If enough of us purchase the testers, we could purchase several 100 packs of DE blades and distribute them to everyone owning a tester and then compare the test results for uniformity. Then sometime later we could send another batch of blades from the same pack. While that would be useful to the community as a whole, for personal use as long as you know what range of test values work for you, that is all that is needed.

 

[SliceOfLife]

Yeah if I keep getting chips using the fulcrum I’m gonna buy some de blades again to see if they survive it.

 

[SliceOfLife]

If I can do it without infuriating my wife I’ll try to get 30mins when I get home in a few hrs testing on it. Make sure I set it up level and cut clean.

 

[Chan Eil Whiskers]

View attachment 979316
Yes.

One of us should get in touch with Sharpening Supplies (or whatever vendor we used) and/or the folks at Edge On Up. Since I typed that sentence I've sent the following email to Edge On Up.



I'll let you know when I know more.

Obviously, this is a problem.

Happy shaves,

Jim

Edge On Up has replied to me as follows:

I think that I have been in contact with the individual you are referring to. It's not as if this issue is unknown to us. BESS test media is constructed of a blend of 100% polymers (plastics). It is inconceivable to us that a polymer fiber could chip steel and, in fact, the picture provided to us by this gentleman does not indicate chipping. It indicates crushing and rolling. Now this effect is possible if the edge is very weak. This phenomena is not only observable on straight edge razors but knives as well but is easily correctable. I don't think that anyone intends to create an edge that is incapable of push cutting a polymer thread that is .009" in diameter without damaging the edge.

I'm attaching a picture that you may find interesting. It shows a brand new biopsy punch that we tested. The punch was constructed of 304 stainless (crappy stuff) and so poorly sharpened and deburred that our test media clearly dented the edge. Out of the package it tested 1400. Once sharpened correctly and deburred it measured 160 with no denting.

We have straight razor users who sharpen in 20 -30 BESS range with no denting. We have microtome users who are in the 10 BESS range with no denting. DE razor blades are all in the 28 - 50 range and no denting.


I appreciate your bringing this to us,

I don't seem to be able to attach the photo. Sorry.

I will, tomorrow or Saturday, have some time to mess around with various blades. I remain uncertain about what is going on here, but somewhat reassured because of Mr. Brubacher's response.

Happy shaves,

Jim

 

[SliceOfLife]

Yeah he sent me the same picture. It’s a foil edge. That’s not my problem, but functionally if I had the angle wrong enough, the results could be similar. I can’t imagine I’d be pushing that far off 90*, but I was hurrying and my desk is a mess, so I can’t say 100% that I didn’t. I’m thinking practically though if that was the problem then I will need to modify the fulcrum so it holds the razors straighter to prevent it in future. I’ll update around midnight if I have time tonight

 

[Chan Eil Whiskers]

Yeah he sent me the same picture. It’s a foil edge. That’s not my problem, but functionally if I had the angle wrong enough, the results could be similar. I can’t imagine I’d be pushing that far off 90*, but I was hurrying and my desk is a mess, so I can’t say 100% that I didn’t. I’m thinking practically though if that was the problem then I will need to modify the fulcrum so it holds the razors straighter to prevent it in future. I’ll update around midnight if I have time tonight

Thanks. I'll look out for updates in the morning.

 

[SliceOfLife]

I’m going to have to try one of my heaviest grind razors. Just took 8 razors to it. If I don’t use the fulcrum I get <30 grams every time and no damage. Using it I get 50+, and huge chunks of the edge destroyed. I think it has to do with the design involving a rocking cutting motion that razors aren’t suited for. I’m wondering if heavier ground razors will handle it better.

 

[bluesman 7]

In their demo videos they only use the fulcrum block as a hand rest when testing DE blades.

 

[Chan Eil Whiskers]

In their demo videos they only use the fulcrum block as a hand rest when testing DE blades.

Yes. Their video show several options and make it clear there's no need to use the fulcrum unless it suits you.

 

[SliceOfLife]

Lol, yeah I got up this morning and looked for razors in the 19 degree range... and damned if natural selection hasn't taken them. 16 degrees is about the heaviest grind I could find among the 60 or so razors I've still got kicking around. So I honed up and 16 degree blade, and before I started, I read the whole manual instead of the quick start guide...

And is says basically the fulcrum is only designed for use with knives and for other things, it may be best to freehand (what I'm doing exactly) or build a special fixture for lowering the blade (what I've suggested would be best).

Still curious exactly the problem, and I'm pretty convinced it's this:

The blade is rotating downward with the toe stationary in the jelly material in the fulcrum. This means that the point of edge that contacts the media must move outward because it's traveling an arc length on a circle, not a straight path (we call this a rocking or rolling cut instead of a push cut). This creates a sawing motion microscopically... and this is why the overly heavy stropping is so good. It's actually DULLING the razor by removing the excessively thin microscopic teeth that a lighter stropping merely aligns (and generally will be gradually removed over dozens of uses + strops), the same teeth that snag in the media when it's moved in a sawing motion and basically do a lemmings off a cliff scenario, plowing out the big "chip" in the edge. So very heavy stropping, rounds up the edge, which still passes @ very low readings because it's still highly polished and relatively thin (compared to knives and DE blades), while making the razor less likely to crumble at the edge as a result of the sawing motion the fulcrum creates.

Problem is, I like a thin razor and I've got a houseful of 13 and 14 degree ones, also I like my strops and don't trust that I won't nick one if I go hog wild on pressure. The result is the edges can't handle that sawing action.

Went ahead and tested the 16 degree razor and it held up even with the fulcrum.
24g without and 21g with the fulcrum, no chips under 400x from either.

Sad part is every 13-15 degree razor I've tried doesn't survive the fulcrum test... and that is MOST of what I own, but at least it seems without the fulcrum we're good.

I've gotten results as low as 8g with the freehand tests and included media just grabbing random razors off my desk.

 

[SliceOfLife]

Damn, I knew I should have watched that video.

 

[SliceOfLife]

Ok, going through my entire collection using this thing. Found 10 razors so far that struggle (<100) with the push cut method... One of the Herders I just bought (the other one works great... not surprisingly, the one working great had REALLY HARD steel, and the one that's having problems didn't) and then a LOT that have been sitting. Going to have to determine if it's a soft steel issue, a corrosion issue, or just that I never put a decent edge on each of them. At least a couple are recently honed, so for them I suspect it's just that the steel is too soft. I'll try removing some depth and see if it's just exterior steel on one when I have time. Still got about 20 more razors to go through, but I gotta head off to work now.

Most of the rest of my collection is in the single digits to 20, with an occasional 50-70 (8k finish or unstropped I'm guessing).