Originally Posted by
David Weaver
On a properly honed edge, stropping removes the wire edge (which can sometimes be a set of several long pieces, and other times just a bunch of ragged bits - meaning it can sometimes show up visibly, but if you're not looking for it it often doesn't, and sometimes you might just think it's a contaminant on your strop if it comes off and is sitting on it. It can look like a very thin hairlike piece).
Stropping on a tool and razor is a bit different for two reasons, first you are expecting perfection out of a razor edge (or as close as can be achieved), and second, the final bevel on a razor edge is about 17 or 18 degrees, and you really don't want it to be steeper or thicker than it has to be. 17 or 18 degrees is fragile, and if a razor isn't up to par quality-wise, sometimes stropping will damage the edge a little bit and you just never quite get the edge you want out of it. On a razor like that, the new trick (old trick?) on razor forums is to put electrical tape on the spine or a razor for finish honing because it makes the edge a bit steeper. I have seen people say "this edge wouldn't settle down until i used four pieces of electrical tape", meaning four layers thick.
On a tool, your final bevel is somewhere between 25 and 35 degrees most of the time, and the fragility of the edge doesn't exist. You're stropping briskly or otherwise to remove any trash that's left on the edge after honing to try to reveal the thinnest part of the edge. It is still important that an unloaded strop of this type is clean, as little bits of metal or grit can nick the edges. It's not hard to keep a strop clean if you pay attention to what you're doing, but it's hard to keep it clean if you just keep it laying face up out in the open all the time.
It's not critical that you keep a tool edge at a specific angle on the strop, I personally like to keep an edge somewhere close to the bevel and strop back and front. I think that gives the most step-up in sharpness from whatever you've gone to and from. The thicker the wire edge, the more pressure you need (if you do some harsh brisk stropping off of a soft arkansas, you can get an edge that's stepped up well and will shave hair despite a coarse stone, but if you do the same thing coming off of a finely settled translucent arkansas, you may not be very happy with the results). Anyway, that translates to stropping off of a coarser stone should be a little more brisk, but the briskness doesn't do anything to help off of a finer stone and a little bit more touch is helpful.
I like a bare leather strop smooth side out and with a little bit of oil on it so that I can see whether there are lines on the strop - if there are and they disappear, I know I've refined the edge and all I have to do is shave hair on my arm to test it and it's easily proved. If the lines don't want to come out and there are a lot of them, I probably have a very coarse wire edge and didn't finsh as well as I thought (this is only the kind of thing that happens when you prepare a new iron and you didn't get it as flat as you think - and it is specifically why you want to have a flat iron back for the last fraction of the edge - so that you can work the wire edge thinner before stropping.
Razor stropping is done on a hanging strop because the pressure on the edge should be somewhat minimal, but you still need the whole edge to be contacted by the strop. A settled in razor strop will reflect an image, it is miles more carefully prepared than a tooling strop. Most new strops are not well conditioned, and will be improved with a couple of thousand razor strokes on them. I'd imagine the old ones were probably like that, though, too. Use makes them better, and much care to leave them hanging in an area where they won't get dirty. The razor is carefully stropped with the spine on the strop *never* leaving the strop when the razor is moving. the razor is flipped back and forth with the spine staying on the strop. Lifting the back can ruin the edge, and the term for it is "rolling the edge", at least that's how I've seen it. Stropping without lifting the spine of a razor is a basic skill needed to shave with a straight razor, and beginners are sometimes rough on razors and strops.
there is no substitute for a razor strop, an edge is never finished as well as it is with good horse leather on anything else, and another nice skill to have with razors is to always work with a stropped edge and hone only to thin the thickness of the edge, never working all of the way to it. Over time a very strong, polished and very keen but smooth edge develops.
I'm not referencing any compounds in the above, because they are more honing than stropping.
As far as the leather goes, for anyone looking to strop a lot of things (it's really a nice skill to have, to be able to use bare leather with good effect), vegetable tanned cowhide can be had all over the place cheaply, and horse butt strips and other scraps of it can also be had a lot more cheaply than they can be had from woodworking or razor retailers. Just search them on ebay and look for a piece that looks relatively clear. If your shop strop gets dirty, which it inevitably will even just with metal swarf that it cleans off of an edge, you can scrape it with a card scraper and re-oil it. You can also sand a strop, but risk sandpaper contamination (though that should be something you could brush out). I use cow leather in the shop most of the time and horse leather exclusively for razors. Nothing else is as good as horse leather (either cordovan or broken in horse butt) for razors. 8/9 ounce veg leather is what I like in the shop, and if I can get horse butt in that weight, I like it, but sometimes it's not available in anything other than lighter weights. It has a woody feel when it's glued to wood.
Shaving strops for me are hanging (can get good edge contact without much pressure), 100% and all of my tooling strops are glued to scrap wood (just use hide glue or whatever and clamp the strop to another piece of wood to get it nicely adhered) because stropping is a firmer thing in the shop and a firmer substrate is nice.
One has to ask what's so great about stropping in the shop if you can just get an ultrafine stone and avoid it, and I'd say the ease of using a single stone or two stones where the geometry of the edge is protected more than it would be if you used a whole bunch of stones. You can use an ultrafine stone in place of a strop, though, and just use it sparingly so that it's just polishing the edge (and not worrying about mirror polishing a whole lot of metal). I just like the leather better.
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