Leather vs Balsa strops

[Wayne Nicklin]

Can some one explain to me when one material is more appropriate than the other in terms of stropping? So far been only using leather with various micro grits and seeing some amazing results.

[cbwx34]

Good question… on a related note, has there been any microscope pics of balsa finished edges? I’ve seen lots of leather, but can’t recall any balsa. This might add some insight.

[wickededge]

I’ll try to get some micrographs of balsa finished edges soon.

-Clay

[Ken Buzbee]

Photos would be great but I’d like a more philosophical discussion of this as well. Never tried balsa myself.

Ken

[Phil Pasteur]

Interesting, Clay posted a question about how much paste people use. I have been thinking about that a bit and doing some playing. I am still not quite ready to form an answer.
The balsa versus leather question is another that is similar. My approach has been to use the balsa strops with my finest compounds. The theory here was that the balsa would contribute less abrassiveness of its own to the process.
Check out this thread:

http://www.wickededgeusa.com/index.php?option=com_kunena&func=view&catid=5&id=2399&Itemid=63#2431

Clay took a whole bunch of pictures of the results from using numerous different abrasives. There are lots of photos, but if you look you will find some that compare balsa and leather with the same abrasives. It seems that perhaps my theory wasn’t all that accurate. Or perhaps better stated, the visual differences did not show a huge difference between the materials.

Lately I have been using 6, 3, 1, and 0.05 micron sprays on leather. I use the 0.125 and 0.1 on Kangaroo and the 0.05 and 0.025 spays on Nano Cloth.

Is this better? I am sure that it is better for shaving, but food prep or rope cutting is affected little that I can detect. Do I feel my knives are getting sharp and are mirror like, sure. Did I feel the same when using balsa, again, sure.

If someone just had to have an answer from me on what to use where, I would still tend to recommend that they use the balsa for their finer compounds. I don’t think that would be bad advice, but I tend to think that they would likely not be able to detect a huge difference in their blade either way.

I do like the way that the balsa feels running over the blade better. It is very smooth, but as Clay points out, more stiction might actually be better if one is hoping to get some part of their results from burnishing. Of course this is something that I can’t quite understand…

As with most things in the sharpening field, I would suggest that you try various combinations of compounds, leather and balsa to see what works in your system. Of course, the only way to objectively analyze your results would be to take some photmicrographs and to devise a method of testing sharpness.
OTH you might just sharpen up a few blades using the different materials and go out and use them..
🙂

Phil

[Steven Pinson]

OK, I will jump in … hold my nose.

I have been using balsa strops exclusivly and I really like them. They allow the paste to be dampened again and again. I posted in another thread about using a toothbrush to keep the strops in order. Here is a ZT0300 that I used the old ceramics (1200/1600) and a progression of paste (.5, 1.0 micron), and spray (.125 micron) with the balsa. YMMV

http://i1133.photobucket.com/albums/m599/SPIN1963/DSCN0115.jpg

http://i1133.photobucket.com/albums/m599/SPIN1963/DSCN0110.jpg

http://i1133.photobucket.com/albums/m599/SPIN1963/ZT0300_1-1.jpg

[BassLake Dan]

..

As with most things in the sharpening field, I would suggest that you try various combinations of (..whatever..) ..to see what works ..

Phil

Yep ! that’s it! The quote of the day, for sure !

At least when you are talking solutions for “cutting ability” against a particular media that the knife in question is most likely to be used against, then that’s a great quote, and it’s the real accurate answer.

However when you are talking about the holy grail quest for absolute “point edge sharpness” then maybe not… then you can look to leather to balsa to “nanocloth” to (and here is my latest toy) optically flat float glass sprayed with sub micron diamond.. in the world of sharp edges ( not “cutting ability”, there is a difference!) you can make declaratory statements about methods to get to the end objective.. only problem is once you get near your goal you have to have a means to measure the result. Problem is that no one is sure how to do that really..

[Phil Pasteur]

I think the OP asked about the philosophy of using balsa. I interpretted that as meaning where in the progression and with what abrasives. That could be way off. Unfortuantely I don’t hink that he indicated his goal. Mayb he will do that for us so that we can better try to answer his specific questions.

I have a bit of a conflict on the choices. For the most part I sharpen for function. After all I use my knives to cut things. That is what knives are in the final analysis, they are tools for cutting things.
For the 50 some years that I sharpened by hand I developed progressions that would result in the knife doing something that I needed it to do. I sharpened knived for divers with a mill bastard file, because they said my “sharp” blades weren’t useful for cutting rope and seaweed. A sharpening regime for a specific outcome.

With my getting into controlled angle “precision” sharpening I am intrigued by trying to get the “perfect” edge. Perfectly straight, perfect geometry to let it hold together at the thinnest apex possible. Oh yeah, and one that is a mirror. I also realize that this is a completely impractical pursuit. Yet I still do it!

Once we get to where the declaratory statements can be backed up by objective testing on a repeatable basis, I can stop treating them as a single persons anecdotal assertion about what works for them. These I find interesting and they give me places to start my own work, but I can’t take them as definitive.

I think we are getting closer with the ability to resolve features down to 0.25 microns as Clay’s new scope should be able to do. At least this gives us the ability to see what is going on. This, and maybe the sharpness tester that you folks are working on, may get us to the point of eventually having a cookbook for getting the perfect edge, but we aren’t there yet.

That is why I advised the OP to play a bit and see what works for him.

Phil

[Wayne Nicklin]

The reason I brought it up was there are so many choices for stopping. Balsa and leather seem to be the most predominate. Was just curious what the general community was doing. I get the give issue that leather affords and the stiffness qualities for balsa. The prevailing theories so far on this forum and a number of others is the balsa affords a better platform for the ultra fine cutting particles. But this can be a personal preferrence based on everyone have different techniques and preferrences. I think all the comments work for either medium based on experience and what that person has in stock to do the job. As some of you have stated, “what is the application?”, it is still fun to take it to the max. I make a point with my clients to discuss what kind of edge are they looking for and more importantly what are they willing to pay for. For a lot of them they have little or no working knowledge of what a blade is capable of doing. In most cases they prefer a slight tooth to the edge and so I stop between 800-1000 grit. Those that want it pushed I go to what I have available in grit size. Going to try my first balsa grit at 1 & .5 micron. Should be fun. Thanks for all the feed back.

[cbwx34]

Check out this thread:

http://www.wickededgeusa.com/index.php?option=com_kunena&func=view&catid=5&id=2399&Itemid=63#2431

I’m glad you brought this back up… I apparently didn’t read it close enough before. There’s a lot of good info in there.

[BassLake Dan]

.. I sharpened knives for divers with a mill bastard file, because they said my “sharp” blades weren’t useful for cutting rope and seaweed. A sharpening regime for a specific outcome.
…

Phil

:cheer: ;)…
here in the Sierra National forest we don’t do much diving, but we sure sharpen a bunch of chain saws ! It’s *all* done with files !

[Phil Pasteur]

I should have added…
under water… water and the speed attainable moving under it… bring a whole new dimenssion to the discussion…

Anyway, I have a hard time keeping my chain sharp…and I use the saw about 5 times per year…
Hit the dirt or sand one time… you are hosed…
No Chosera 10K need apply !!!

🙂

[Mark76]

I’ve been doing a lot of experiments in which I compared, among others, leather strops and balsa strops. You can find the results on my blog[/url].

The obvious differences between leather and balsa are that:

• leather affords more than balsa, which is very stiff
• leather has more draw (“stiction”) to it than balsa, which is very smooth

The fact that leather is less stiff than balsa makes leather more suitable for turning a multi-beveled edge into a convex edge. Clay has done a few videos on that and you can find a few posts about that on my blog.

If you don’t want to convex an edge, but simply strop a final bevel, the stiffness differences between balsa and leather are negligible as far as I have been able to observe. For example, on the WEPS, a leather strop kept the edge of the edge just as straight as a balsa strop.

You can use the fact that leather has a bit more draw to it than balsa if you wish to create a mirror edge. To create such an edge, it is more important to burnish the edge than to abrade it. The draw leather has to it aids in burnishing. However, the Wicked Edge stropping pastes already provide a lot of draw themselves. So if you use these pastes, the difference between leather and balsa in this respect becomes less important. Some of the pictures on my blog show that balsa can get an incredible amount of “stiction” if you use these pastes. Also see a recent topic by Clayon the different effects of stropping (abrading, burnishing, honing).

A less obvious difference between leather and balsa are their own abrasive qualities, i.e. their abrasive qualities when used without any stropping compound. Clay has posted some pictures (perhaps in the thread Philip referred to; I cannot find them back immediately) of the effect of a leather strop on a nearly clean edge. It appeared that leather (at least the leather used for the WEPS strops, which I think is quite smooth) has abrasive qualities of its own in the submicron range. I cannot say whether these are relevant already when you use a 1 micron compound, but when you’re at about 0.5 micron, these are almost certainly relevant.

So indeed, balsa is probably more suitable at the submicron level. However… I don’t know how effective balsa is with diamond sprays in these ranges. The space between the ligaments balsa is made of is apparently about 0.5 micron. So if you use a submicron compound, the abrasive particles may partly disappear in the “crevices” between the ligaments. Obviously, not all particles will disappear in these crevices, but this may make balsa less effective. But, as I wrote, I just don’t know. If anyone knows about any experiments in this area, I’d be happy to know.

I nowadays use a special cloth mounted on aluminium when I strop at the submicron level. This cloth is fabricated specifically to hold tiny particles in place, but not to cause any abrasion by itself. I am quite happy with the results, but cannot substantiate it with any microphotographs.

Fortunately Clay now has a 2000x microscope 🙂 .

Molecule Polishing: my blog about sharpening with the Wicked Edge

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