Quote Originally Posted by mparker762 View Post
I used to think so. AFAIK I'm one of the guys that started this idea that pastes weaken the edge, and if you look back in the archives I came up with a variety of elaborate theories to explain this. But I've since reevaluated that theory in light of some experimentation and no longer believe it's valid. Sometime back around the time of the "Grand Chronik Review" I took a couple of old razors and did hundreds of laps with them on a variety of pastes (diamond, Dovo Black, and chrome oxide) and substrates (leather-on-wood, bare wood, vellum-on-wood, and hanging linen and leather) and never really demonstrated to my satisfaction that high levels of pasted stropping actually degraded the edge. What I did find was that too much paste was bad, and too much pressure was bad, and on a pasted hanger too much slack was bad. But I never did find that hundreds or even thousands of laps on pasted strops were bad. One of the razors I sent out in the Chronik Review had over five hundred laps on chrome oxide on a hanging strop, and if the recipient noticed any problems he didn't deem it worth mentioning. My 7/8 W&B Concave grind had close to 800 laps on a variety of pastes, finishing up on the Dovo Black paste, and the only lasting effect was that it's too sharp to shave with comfortably.

The only link I really found between pasted stropping and edge deterioration was that as the paste loads up with swarf then the draw tends to increase, which tends to cause you to increase pressure, which then which harms the edge. But this is an effect that occurs with unpasted strops as well (I can't stand high-draw strops like latigo for this reason). But absent that, I found that I could strop an edge on paste for many hundreds of laps and the edge remained sharp as ever. Using a non-compressible substrate like bare hardwood or vellum-on-tile makes this much more clear, since they're more resistant to pressure (with a full hollow, increasing pressure flexes the blade more than the substrate, which actually lifts the edge away from the paste)

The pasted hangers and even to some extent the leather-covered paddles all tended to cause some degree of arching in the bevels, but as long as you used consistent tension and consistent (and very light) pressure on the razor, this doesn't really cause any problems. If you think about it a slightly arched bevel is similar to a double or triple bevel - only continuous instead of stepwise. The problem comes in with a very heavily arched bevel which makes the final angle at the edge too steep. The knife sharpening guys have been doing the multi-bevel thing for years and from what I've read believe the multi-bevel edge is inferior to the smoothly arched edge, and the only reason to use a multi-bevel edge is because of the difficulty of achieving this on a knife without a continuous slack belt sharpening system.
Thanks so much for your interesting reply. That is the most valid explanation ever read about the matter.