Plain Stropping - Looking for Advice

[Russell Cook]

Hi all,

I've been reading a lot about how stropping with a trailing stroke on untreated leather, newspaper, palm of a hand, denim etc can improve the edge on a tool.

I was hoping to ask 3 main questions.

1) Are the materials listed above all reasonable?

2) How important is the absolute flatness of the surface when doing this?

3) How important is the angle you strop at? My impression is that this kind of stropping is not removing material apart from the wire edge, so the hitting the perfect angle is not essential as you aren't in danger of rounding the edge.

Any tips would be great.

[John Coloccia]

My opinion in red

Hi all,

I've been reading a lot about how stropping with a trailing stroke on untreated leather, newspaper, palm of a hand, denim etc can improve the edge on a tool.

I was hoping to ask 3 main questions.

1) Are the materials listed above all reasonable?
IMHO, leather is the most reasonable

2) How important is the absolute flatness of the surface when doing this?
Completely unimportant. Obviously, it should be somewhat flat, but just a piece of plywood or MDF is PLENTY flat. I'm sure your bench is plenty flat as well. I tend to use with MDF, Mahogany or Maple to make my strops because I always seem to have an abundance of those materials around.


3) How important is the angle you strop at? My impression is that this kind of stropping is not removing material apart from the wire edge, so the hitting the perfect angle is not essential as you aren't in danger of rounding the edge.
Depends on how much pressure you're using. Yes, you can round over the edge. In practice, I take the last couple of wipes at a greater angle than the bevel, and I do so very very very lightly...maybe not even the weight of the iron. Very light Other than that, I do try to generally hit the same angle as the bevel. I don't worry about it too much. I just try to be reasonable about it. If you think about it too much you'll never learn to feel it, so just do it and experiment.

Any tips would be great.

[David Barbee]

Any medium that will hold the stropping compound and is relatively flat will work for stropping. Many favorites are leather (both smooth side up and down), cardboard, mdf, wood block, etc. Some folks prefer a harder stropping surface, some don't. Both work fine, i prefer leather. This is really something you shouldn't over think. I feel 100% positive that you will be successful your first time. My technique is really simple. Find your bevel as if your were free hand sharpening. Pull the chisel/plane iron over the strop surface but stop short of the end of the strop, then lift the chisel/plane straight up off the strop. Don't be tempted to tilt the chisel/plane up at the end of your stroke. This will round over your cutting edge.

I keep a strop on my bench when I'm doing chisel intensive work, such as chopping dovetails. I'll chop my dovetails an then strop the chisel before I begin any clean up. This keeps the chisel sharp. You will spend a lot less time at the stones if you keep your chisels stropped at the bench. When you notice that stropping isn't getting the chisels as sharp as normal, its time to go back to the stones. It generally just takes a few strokes with your medium stone to get your keen edge back.

For me, stropping took my sharpening to a whole new level. It took me my edges from sharp to super sharp and most importantly, I spend more time working and not standing in from of a waterstone pond. Gets some compound and give it a try.

David B.

[David Barnett]

I've been reading a lot about how stropping with a trailing stroke on untreated leather, newspaper, palm of a hand, denim etc can improve the edge on a tool.

I was hoping to ask 3 main questions.

1) Are the materials listed above all reasonable?

1. Yes, although some will work better or make more sense than others.

The surface roughness of human skin, from Nanotribological Characterization of Human Hair and Skin Using Atomic Force Microscopy, is measured at 80 ± 28 nm, or 0.59 ± 0.2 μm. The silica content of skin, such as the human palm, varies individually and with age. Less dry, somewhat dubious but perhaps more entertaining is Human Skin Strops — A Gruesome Traffic Carried on by Impecunious Operators in the Dissecting Room:

"It is also well known that a razor can be nicely finished on the palm of the hand. This fact led to the use of small crude strops made of bits of flesh, secured in the dissecting-room. The possibilities of this human flesh strop appealed so forcibly to the practical mind of one of the students that he began experiments which resulted in the introduction very quietly on the market of a razor strop made of human flesh."

Paper and other pressed fiber materials such as felt, can make effective strops. The fibers of papers moulded and couched by hand, that is, papers with the less aligned fibers from the mouldman's "shake" of the mould* to lock the longer fibers, seem better than machine mould made and continuously formed (Kraft, etc.) papers, at least to me.

Linen has long been used those who favor it for straight razors.

Leather, treated and untreated, works well, with horse butt held in high regard.

There are other stropping surfaces, of course, but these are the ones you mentioned.

I'll leave it to others to address 2 and 3.

*Papermaking: The History and Technique of an Ancient Craft, Dard Hunter.

[Chris Griggs]

I'm one of those weirdo's who, as Dave W puts it "has an aversion to leather". Though I have used some scraps of leather I had around in the past its not something I have/use anymore so can't really speak for that.

What I can say is I've tried a number of non-leather mediums, and of them my favorite is my palm. Paper/newspaper works ok, as does a pant leg but for bare stropping without compound my palm is unquestionably my preference. With compound, I like balsa as a medium the best. I also have one of those Wood Is Good synthetic urethane strops that works with compound (not bare), and its what I use in the shop but I like balsa better (which is what I use for my razor compounds)

[and...no I'm not telling you or anyone else not to use leather, I'm not preacher. Just sharing my experience :-)]

[Stuart Tierney]

Hi Russell,

Very quickly as my time is limited...

(Always!)

1; All of the materials are completely reasonable, I've used them all and they all work. I am tending to use my palm more often, for which you can blade Dave Weaver.

2; My palm is NOT flat, and if it was, I'd be worried. Flat is not so important, but it's nice if you can get it.

3; Very slight angle, nothing more. This kind of 'stropping' is merely making sure the slip of metal at the very edge is pointing in the right direction, and any remnants of wire edge/feathering are teased away from it. Maybe there is a very slight abrasion going on, but mostly it's simply to make sure everything is pointing where it should be and nothing that'll degrade or damage the edge is in place.

If you need compound to bring up the edge, that's something else entirely. Most folks I see are using a loaded strop of some kind, and it's a completely different animal to simply cleaning up an already good edge by effectively 'wiping' it against something.

I'll not go into stropping with abrasive compounds on the strop. I'll go so far as to say that I do not do so unless the edge is an unusual shape.

Stu.

[Bruce Mack]

I also will not use leather. MDF or the Wood Is Good strop, each with chromium oxide, work for me. The urethane seems better for curved carving gouges.

[David Weaver]

Hi Russell,

for which you can blade Dave Weaver.

Ouch!

palm strop is excellent for a fine edge, it does what you need it to do.

Any leather is nice, I personally like the smooth side out on anything that I've used because it makes it a lot easier to keep the leather clean, and clean is important.

The worse the edge (e.g., if you come off of a washita stone, leather > than palm only because the edge isn't ready for the palm yet) the better leather fares vs. palm. On an edge of that level, it really makes no difference leather out or in, but on a smoother quality edge where smoother finishes the surface of the wood, a clean smooth side is better. (no shavers strop their razors last step with anything but smooth, and the smoother the surface the better the edge - freshly made horween shell is tops of everything I've ever used, but it is not durable. The leather is, but the surface treatment is not, and it's above woodworking price).

Pressure of stropping can also vary with edge finish. A properly sharpened fine stoned edge (trans ark, fine waterstone, etc) needs a very clean strop and little pressure. There isn't much to remove, but the edge will still be improved. Maybe not practically for woodworking, but the sharpness will be better.

Sorry to impose my ridiculous thoughts. In the last two years, I have paid a lot of attention to various strop materials trying to get around paying a lot for a designer leather strop. In the end, I did buy a shell of horween, a couple of horse butt strips (which is a lot of leather) and veg tanned cowhide, and then a kanayama shell cordovan strop (no clue where their shell comes from, it was a lot different than horween)

8 or 9 ounce veg tanned smooth cowhide is good as any for tools (well, horse butt is a little better esp. if you're going to use goop) and it's cheap. Horsebutt once broken in is arguably better, but it was a month of stropping before my horse butt strop's strong silica actually stopped decreasing the sharpness of the razor after honing. Horse butt often has wrinkles and such in it, and sometimes veg. tanned cowhide isn't as smooth as people say it is. If it's coarse, just oil it up pretty good so it doesn't hurt the edge too much.

Whatever anyone does, if you use any strop as an improvement to a fine stone, keep it clean. Any particles, even on soft leather, will ding a chunk right out of an edge or scratch it up. store it in a drawer or take it out of the wood shop when not in use, whatever.

One other thing for the newbies, a very sharp edge will shave hair easily (as in one pass and everything is gone without much pressure and regardless of cutting angle) on both sides. you can only do that if the wire edge or remaining particles are off of the cutting edge, and you weren't too rough with final stropping (otherwise heavy handed stropping will just point the edge one way or another).

If you use a "tweener" sharpening stone, like a hard arkansas or even a black or trans ark, notice that you can strop an edge on your palm quickly and actually bend the particles around and choose which side shaves the best. There's no reason to have a razor quality (both sides shave easily) in the shop.

[Jonathan McCullough]

I really like the idea of having a urethane strop. Seems like it would be uniform and take chromium powder nicely.

[Chris Griggs]

I really like the idea of having a urethane strop. Seems like it would be uniform and take chromium powder nicely.

Its okay. The one problem I had with it is the thin piece of wood it was attached to cupped pretty badly. Now it certainly doesn't need to be dead flat but the cupping was bad enough on mine that I noticed it. As in it polished a tiny back bevel on a couple of my chisels...nothing major that couldn't be honed right out but not ideal. So anyway, I peeled the urethane off the handled piece of wood, and now I just set it on my bench which is flat enough. I'll probably glue it down to a piece of walnut, that has already acclimated and moved a little after being planed flat and just make sure I glue it to the side the is slightly convex as opposed to slightly concave (or just stick it to some mdf)

I also don't think it works that well with dry abrasive, so when I sprinkle CrOx on it I add a couple drop of mineral oil or water and sorta paint it all over...and yes this gives it a nice uniform coating.

Anyway, I do find it to be nicer and more uniform than just MDF, but realy mdf or balsa do the same thing. The urethane is fairly firm which is nice...i like a bit of firmness when I'm using compounds as it helps avoid rounding over. I'd really like to fine something slick, hard, and non abrasive to apply my CrOx to so I can take strokes in both directions and use it like and ultra fine stone.

(to Dave's point about contamination...I keep mine wrapped up in a paper towel when not in use. You definitely do not want loose grit that is floating around you basement workshop to contaminate your final step in the honing process)

[george wilson]

I'd think that after the human skin got dried out,it'd be no better than normal leathers. I haven't gotten weird enough to want to try it!!

I think David Weaver is likely the strop expert here. I have used a cowhide leather strop,smooth side out,most of my career. Lately,I have made an MDF strop with chromium oxide on it. It works well,too. Somehow,I'm more concerned about dust in the shop getting on the rigid surface of the MDF that I was about dust on the leather. I blow them off,but I guess I think the dust would tend to sink into the leather as a blade passed over it,as opposed to getting ground into the edge on the rigid MDF strop. Maybe I'm paranoid!! The leather strop with some Simichrome or CrO has served me quite well.

[Tony Shea]

Interesting. I knew there were some geeks (including myself) about sharpening, but stropping past the point CrOx seems a bit obsessive when you're in the shop. Even when dealing with pine I can't imagine needing my edge that sharp. Don't get me wrong, I am very OCD about getting my edge just about perfect but going past a compound and strop should be limited to those honing something other than woodworking tools.

I'm not sure what everyone else does for a living or how hard they work their hands, but I think stropping on my palm is a step backwards even compared to my 8000 stone. David W. talks about contamination and avoiding it, well there just isn't any avoiding it on my palms. Just today I have been crawling around in an interstitial crawl space above a laboratory running conduit for temperature control wires. Just the crawling on my hands has contaminated them for at least a week after I am no longer up there. Metal shavings, wood splinters, fiber glass duct insulation, and probably worst of all the hard calluses that feel like a piece of 120 grit sandpaper. Just saying.

But in all seriousness I truly think stropping on something without compound is probably not needed when dealing with woodworking tools.

[paul cottingham]

I have two strops I use regularly, a horsebutt one and a maple one. I charge them both with green rouge, and they work great. Don't ask why I have two, I don't really know myself. :-)
i have been using them with pressure, cause a well know woodworking personality does it that way. I'll have to try it more gently as well.

[Chris Griggs]

But in all seriousness I truly think stropping on something without compound is probably not needed when dealing with woodworking tools.

Think of it more as being two different things. Bare stropping doesn't really take things past the point of compound so much as it takes the edge you have and maximizes it by aligning the edge and removing any remaining burr.

Stropping with compound I really just think of as honing on a very very fine stone, especially on a really hard surface.

Your hands are definitely dirtier than mine.... I spend all day at a keyboard, working with databases, spreadsheets, and statistical software...doesn't exactly get my hands dirty.

[David Barnett]

I also have one of those Wood Is Good synthetic urethane strops that works with compound (not bare), and its what I use in the shop but I like balsa better (which is what I use for my razor compounds).

I've tried all manner of strops, and while urethanes do work, I've found promising non-leather alternatives in both the bookbinding and shoe industries. Clarino™, a dense nylon-polypropylene based microporous leather simulant from Kuraray, is versatile and worth consideration. I have strops made from samples, sueded and natural, and it can be used neat or charged.

So many materials, so little time. Me? I love parchments, vellums and horse butt.