Tony and other strop mavens,
Have you ever tried to use the flesh side of the leather as a precursor to finishing on the grain side? I'm curious if it will work at all like the linen member of the strop combo.:thinking:
Bruce
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Tony and other strop mavens,
Have you ever tried to use the flesh side of the leather as a precursor to finishing on the grain side? I'm curious if it will work at all like the linen member of the strop combo.:thinking:
Bruce
Depends on the hide and the tanning process used blah blah. I would say that it is used by some for a pre-finish strop like linen but I prefer it for it's ability to hold pastes better.
PuFF
I have a vintage Russian leather strop in great condition. It strops on both sides. One side is a "sharpen" side with a small diamond pattern cut into the hide. The other a "finish". It works great. I'm not for sure if this is how it is supposed to be used. I read this from Hand American's site (http://www.handamerican.com/leatheri...ian%20Style%29).
I'm still waiting to hear other's experiences, if any with the same type of strop.
I have used the flesh side quite often on my own strops and have occasionally offered them for sale. I was thinking of releasing some again as my current supply of Latigo hide would lend itself well for this use. The back must be reasonably firm and of even texture. Not all hides will work, or all sections of each hide. When the surface is right it makes a fine substitute for linen.
In my first year of business one of my most popular sellers was my "Tri Strop". It comprised of leather from an Illinois #127, leather from an Illinois #827 (which is reversed, flesh side leather) and an Illinois Linen all held in a swivel loop. It was very popular but I could not get consistantly good pieces to use. I made my own for a while as special orders and once past the post vacation rush will have a version again.
While the reverse side also works well with pastes I'm not a huge fan of pasted hanging strops as many types of natural leather are prone to cupping and applying water based pastes could make it happen even easier than it does already.
Tony
Tony, any good info on these old Russian's with the diamond pattern on the back (- linen)?
-Brian
Brian,
I have one myself with the same diamond pattern but know nothing abiout the "why" of the design.
I did just reply in another thread about texture in strops....effective or marketing?
The raised nibbs, bumps, pebbles, cuts, etc....do have the effect of slowing or interfering with the razors movement across the strop making it feel like there is more resisitance or draw. But, all of the nibbs, bumps, etc... reduce the contact area between razor and leather so they should effectively reduce the friction between razor and steel. I guess it's a toss up whther the effect of the bumps is canceled out by the reduced area or not.
When we buy or restore a strop we are concerned with having a flat, smooth, 100% contact patch across the entire blade, when we speak of texture strops we are reducing this contact patch by maybe 50% or more depending on the nature of the textured surface.
As a stretch on this idea does a bald tire have more friction against the road or less? If less why does a drag racer choose a slick tire? On a lapstrake constructed boat (boards lapped clapboard fashion), does it have more friction or less in the water than a smooth hulled boat? Sitting still it has more surface area as every ridge contacts water, at speed the water passes over the ridges leaving a wake of bubbles in the lapps reducing contact and friction. How about a golf ball with all the dimples?
Any thoughts? ( I obviously had plenty of time to think crazy thoughts while on vacation but not enough time to come to any conclusions <g>)
Tony
I lightly rub the flesh sides with a pumice stone before using them. I did this to the strop I bought from Damon, member on this forum and the the wapeinica strop which I bought off of ebay. I cut the linen side off cause it curled up on the edges , smoothed out the flesh side with a stone and it's now a right decent strop.
Ernest
[quote=Tony Miller;120261]Brian,
I have one myself with the same diamond pattern but know nothing abiout the "why" of the design.
As a stretch on this idea does a bald tire have more friction against the road or less? If less why does a drag racer choose a slick tire? On a lapstrake constructed boat (boards lapped clapboard fashion), does it have more friction or less in the water than a smooth hulled boat? Sitting still it has more surface area as every ridge contacts water, at speed the water passes over the ridges leaving a wake of bubbles in the lapps reducing contact and friction. How about a golf ball with all the dimples?
Any thoughts? ( I obviously had plenty of time to think crazy thoughts while on vacation but not enough time to come to any conclusions <g>)
Tony[/quote
At last, a boat analogy :) Problem is I can't elaborate on that ,Tony said it all. :nj
PuFF
Puff,
I thought of you when I typed that one! I was a real wooden boat fiend way back in the day.
Tony
Hmmmm... You got me thinking. To quote Hand American,
"This gave the leather a robust red color and a distinctive minty odor. In addition, if the tannery found that the finished hide was too smooth to be effective as a strop, patterns were embossed in the grain to increase the drag of the hide. A diamond pattern similar to ours was often used."
The Russian I have has this diamond pattern, but each little diamond summit has a bit of an unfinished look/feel to it. Just a tad unfinished by comparison to the finished side.
I'm thinking that the overall effect on the blade by comparison would be like the difference between course and fine sandpaper. The patterned side does have more drag than the finished side. It might also have served to reduce stropping time (for the barber)?
BTH88,
A good example of a "modern" Russian strop would be the Illinois #827. On this one the working side is the reverse, flesh side of the beast and the back side is filled with small ridges left by an embossing/rolling process used to compress the leather. The front looks like compressed terrycloth. On a good example it works very well, on others it deteriorates into a wolley mess then a pumice stone can be used to get the texture desired.
Dovo and jemico both make a Russian strop that is a reddish color but no indication of other differences. Jemico did make a very small pebble grain model, also a deep red in color that was very hard surfaced and quite effective.
Tony
My homemade oak tanned cowhide strop works on both the finished and unfinished sides really well. To Tony's point, the unfinished side actually strops "faster" than the finished side (less resistence and smoother). This is probably due to both the smooth leather having more contact area and I also added a thin dressing of mink oil which adds drag. I enjoy using both sides and haven't yet figured out what finishing qualities are added by the separate sides.
Dewey
I think the "faster" you mentioned is the real advantage of the reverse side. I have found it makes a nice substitute for linen. I think Chris Moss on SMF is a big fan of preliminary stropping on rough leather and finishing on smooth leather and his suggestions spurred me to look at offereing my rough leather once again.
Tony
Golf Balls and Dimples:
In the early days of golf in Scotland, golfers discovered that their old golf balls went farther than the new, smooth ones. The beat-up balls reacted differently to the forces they encountered while flying through the air. It wasn't long before golfers were intentionally pitting their brand-new balls to improve their games. By 1905, golf balls were being manufactured with dimples, as they have been ever since.
Why dimples?
All flying objects are subject to the forces of lift and drag. An airplane produces lift when the air flowing over its wings creates lower pressure than the air below, causing the plane to rise. At the same time, the plane's forward motion creates drag or resistance. A golf ball can produce lift in a similar fashion. For example, if a struck ball has backspin, which changes the flow of the air around the ball, it produces lift, a force that is perpendicular to its flight path. This is a result of high pressure being created at the bottom of the airborne ball relative to its top, and the lift is a consequence of these differences in pressure. At the same time, the struck ball also experiences drag, a retarding force that acts in the direction opposite to the direction of its flight path. Part of the drag force is due to the flow not being able to stay attached to the surface and come together on the back side of the ball. This separated flow forms a low-pressure wake behind the ball, and the difference between these pressures and the higher ones found on the front of the ball produce what is termed pressure drag.
The other part of the drag force experienced by the ball is due to skin friction, a tendency to pull the air nearest its surface along with it. It's just air rubbing on an object, which retards its motion. Skin friction depends largely on the pattern of airflow in the boundary layer very close to the surface of the ball. If the flow is smooth, or laminar, it has lower skin friction, but is less able to stay attached to the rear surface of the ball. A turbulent boundary layer, however, although having more skin friction, is better able to stay attached to the back of the ball. That is where the dimples come in.
Putting the dimples on a golf ball forces the boundary layer to transition from a laminar one to a turbulent one. The greater mixing of air in the turbulent boundary layer allows passing air to cling to the flying ball a little bit longer before it separates which in turn narrows the ball's wake, the region of low-pressure air created behind it. A smaller wake means less air pressure pulling on the back of a golf ball as it sails toward the green. In effect it's a positive trade-off: The ball pays a skin friction penalty, but gains a pressure drag advantage. The difference is huge in terms of the distance a golf ball can be driven. Dimpled balls can travel nearly twice as far as smooth ones.
<<<<In effect it's a positive trade-off: The ball pays a skin friction penalty, but gains a pressure drag advantage.>>>>
Much like the textured vs. smooth strop tradeoff, more friction, less surface contact vs. less sensation of friction, more surface contact. What we don't know though is the effect.
Thanks for the golf ball details. I know I have read that in the past but didn't remember where.
Tony
The analogy doesn't hold up because when we consider air we're treating it as a fluid (oh, how I hated fluid dynamics :) ) and you can't say the metal of a blade does (no laminar and turbulent flow with a blade iirc. :) ) act like a fluid.
Tyres gripping in the case of racing slicks rely on them burning out and melting the surface of the tires which isn't exactly going to happen with our strops and razors either afaik. :)
The inner flesh side of the bits of leather I have are all a little rough for my taste, except for splits of course but then that's never been touching the flesh so to speak.
Murph,
The analogies were more to get people thinking about the differences.
Any thoughts on the textured strop surfaces increasing effectiveness or reducing it in regards to stropping. I know thw texture affects surface contact, reducing that but does the illusion of more resistance really pan out in practice?
Tony