Thread: Verhoeven Paper Question

Originally Posted by Sticky

I can and do regularly remove small burrs (on German and Swiss chipcarving tools, mostly) all the time. This is sometimes done using plain leather on a flat surface. Here's a reference by just one expert on woodcarving: How to Carve Wood: A Book of ... - Google Book Search. Oddly, I have one of the very first editions on my own bookshelf. It originally came out in 1984. I just did a quick google search on "can stropping remove a burr" and found it near the top of the list.

I have come to believe that plain leather demonstrates abrasive qualities every time I use it.

All sources I ever read, including your link, always advice to dress the leather with an abrasive compound.
But strictly spoken, everything on this planet has some abrasive qualities even a cucumber sliced lengthwise in half. Entire mountains are reshaped by mere rainfall. The big question is, have we the patience and time to wait for it?

Originally Posted by FatboySlim

Could it be this study under-represents razors as an anomaly, in order to concentrate on knife-class edge angles?

Verhoeven conducted the leather experiments on flat hones and flat leather strops, using this jig, leaving the specimen blades attached in the jig during the entire honing and stropping progression:

(picture taken from page 18 with reference to the original article at http://mse.iastate.edu/fileadmin/www...nifeShExps.pdf)
He checked his results at 3000X magnification, using an Scanning Electron Microscope, and found no discernible diminishing of 6000 grit abrasive grooves.
That is as scientifically bulletproof as it gets. Verhoeven had to change his mind about leather: "(...), it was initially thought that a clean strop would contain enough natural abrasive material to produce a marked improvement in the quality of the edge. As a result, several initial experiments were done with clean leather strops,including an experiment with alternate 3 cycles of 4 leather stropping plus a single 6000grit sharpening. In all cases the clean leather stropping proved ineffective in comparison with the dramatic improvement found with the chrome oxide loaded strop." (page 22 of same document)

For what it's worth, in my opinion, that closes the case. If stropping has an affect on an edge (and I agree it does), it clearly is not the result of any significant abrasion. The most likely explanation that remains, is proper alignment of the extremely narrow strip of erratic steel at the very tip of the edge. I advocate the use of the word "fin" for that strip. Stropping on clean leather is friction and it aligns and straightens out the fin of an edge. Stropping on paste is an entirely different thing.

Bart.