Thread: Stropping is King

[quote=PuFFaH;74586]

Because the science and theory say "it won't work" it doesn't explain why it does.

Come on it's not rocket science. It has to follow the basic rules of physics, assuming you're reality based.

I can't be persueded that stropping doesn't remove enuough material to sharpen an edge and polish at the same time. Granted it will take longer, but then I'd expect it to.

Normal leather stropping does not. Prof Verhoeven found that in his sharpening treatise. Science doesn't say it won't work. It says everything is abrasive to some extent. After all rocks are worn away by water. And you're right it would just take longer. A lot longer. Forty reps or even 80 reps on plain leather won't do it. Ten times that many might. That's based on the fact that, on the average, refreshing with a .5 strop is required after after 10 shaves, and it typically involves 20 reps. In other words after 10 shaves you need to remove as much material as 20 reps on a .5 micron strop.

I'm not saying a strop can't do it, but it would have to be abrasive enough to remove that much material. If you'e doing 40 reps each time, you would have to be abrasive enough to remove the material in 10 days (400 reps, 800 reps if you do 80 at a time). The number of reps is kind of typical, and the fact that abrasive honing or stropping is required after ten days tells you that the typical leather stop doesn't cut it, as confirmed by the profs research. Now if you did ten times that number of reps or used a machine, it might.

After finish honing with say a 8-12k hone, you could only go to something finer for the finishing steps with a strop. I base this on the leather strop wheels i use on my lathe for sharpening wood turning chisels. After grinding to the correct bevel and sharpness, I then put them across my leather hone mop. This you can see metal being removed all be it, slower.

This just goes a long with what I say. How many reps would you have to do by hand to get the same result?

I will concede that heat is produced but this is not what removes metal, it's the abrasive qualities of the leather.

Right, but the heat tells you it's being abraded much faster than by hand, where there's no heat.

I must point out that the speed is 300rpm

To get a feel for how many manual reps this would be, multiply the belt speed by the time you hold the blade in place for one side. Then divide by the length of your strop. This is a very conservative estimate of the equivalent number of manual reps.

So my point is that a plain leather strop does sharpen a razor all be it slow and finely. To use pasted strops just speeds up procees like going from 4k to 8k on a hone.

I agree, but to get the effect you're looking for with the number of reps being used, you need something more abrasive than plain leather. The abrasive quality would probably have to be the equivalent of a 500K grit, or .05 micron. I say Scott must have that on his strop. That's the only physical explanation of why he would never have to refresh his razor. The rest of us don't have the abrasive and need to refresh or do occasional honing.

Scott's approach is just an extension of refreshing. When we refresh we do a little material removal every ten days, as compared to doing a lot of material removal every few months. Scott removes a minute amout of material with every stropping, instead of removing a little every ten days.

[quote=mparker762;74645]

I can easily believe that an unpasted linen strop is some reasonable percentage as abrasive as a .5 chrome oxide paddle - if it's even 2% as abrasive then giving the razor 80 firm laps on it may be equivalent to as much as 10 light laps on CrOx, which will make a substantial difference in the quality of the edge.

I estimate it would have to be at least 10% to do it with 800 reps (80 per day for 10 days).

Well, most guys do their daily stropping with very little pressure, but these experiments seem to involve a lot of pressure; so 80 laps with a lot of pressure might equal 2-3 laps on CrOx with a lot of pressure. But most of us don't use pressure on the CrOx paddle, so maybe it's equivalent to more light laps?

I'm just guessing here as to what might be providing the sharpening affect these guys are seeing. It could also be accumulated grit on the leather strops from stropping right after honing or paddling that is providing some additional abrasive affect.

Originally Posted by PapaBull

One theory I've heard put forward by someone very experienced in metallurgy is that the oxidation and removal of the oxidation is what really causes the "fin regeneration". Fishhooks and files are two steel tools that are acid sharpened. Essentially, they're sharpened by chemically oxidizing the steel. When the oxidation is removed, a fresh layer of steel that is "chemically sharpened" is revealed.

It's plausible, but it just explains why material would need to be removed occasionally. I think we all agree on that.

As best I can tell, stropping simply polishes and refines the edge by abrasion.

Sharpening experiments done by Prof Verhoeven show that normal leather stropping after honing doesn't remove enough material to improve sharpness. I do a few reps (15-20), because I find the small amount of polishing adds smoothness.

It's generally accepted that what stropping does is to realign the fin. It's made up of micro-teeth, which get bent in all directions by shaving. Within 2 days they come back most of the way, but not all the way. Stropping just pushes them the rest of the way (stands them up), making the edge effectively thinner (sharper). After about 10 shaves, stropping no longer does it. It may be because of mico-oxidation. Refreshing may remove that oxidation, stroring the sharpness of the teeth.

[quote=mparker762;74757]

I'm just guessing here as to what might be providing the sharpening affect these guys are seeing. It could also be accumulated grit on the leather strops from stropping right after honing or paddling that is providing some additional abrasive affect.

He said he put urethane on the strop and then roughed it up with sandpaper. That could be it.

The accumulated grit wouldn't affect the leather ecause he uses linnen first. If it left enough on the linnen, why wouldn't the rest of us get the same result?

What I'm beginning to think is that we have a third form of razor maintenance: leather stropping and periodic honing, leather stropping and frequent refreshing; and just leather stropping with a slightly abrasive strop. I estimate that the third approach could be done with something like a .05 to .025 micron abrasive.

Originally Posted by Joe Lerch

I say Scott must have that on his strop. That's the only physical explanation of why he would never have to refresh his razor. The rest of us don't have the abrasive and need to refresh or do occasional honing.

Scott's approach is just an extension of refreshing. When we refresh we do a little material removal every ten days, as compared to doing a lot of material removal every few months. Scott removes a minute amout of material with every stropping, instead of removing a little every ten days.

Joe, you say there is some type of abrassive on my strop, but where did it come from?? I certainly haven't applied any paste or abrassive in the ten years I've been using it. And I've cleaned and dressed this strop many times over the years. It would seem that any paste that could have ever been on the strop would have been removed long ago or reduced to an ineffective amount.

Or, are you suggesting that horse hide cordovan strops are more abrassive than cowhide? That could be so, but I don't know.

Also, I do about 20-30 round trips on both linen and leather before each shave. Isn't this the standard number for most users?

It would be interesting to hear from others who use the Dubl-Duck strops.

Scott

Originally Posted by honedright

Or, are you suggesting that horse hide cordovan strops are more abrassive than cowhide? That could be so, but I don't know.

Or a different tanning method. I've noticed that my edges last longer since I switched to a handamerican strop, and they supposedly use leather that is tanned with a special tanning method that leaves silicates in the leather (or more silicates).

[quote=honedright;74761]

Or, are you suggesting that horse hide cordovan strops are more abrassive than cowhide? That could be so, but I don't know.

I don't know. I'm just saying the slight abrasive has to be there. You mentioned putting on some uretahne and sanding it. Maybe that's enough. The abrasiveness required for 40 reps would probably be finer than a .025 micron (notice the decimal point) abrasive.

[QUOTE] Also, I do about 20-30 round trips on both linen and leather before each shave. Isn't this the standard number for most users?/QUOTE]We had an experiment here that showed more than 60 made no difference (in terms of stropping only), and 45 seemed to be the sweet spot.

It would be interesting to hear who maintains their razor with stropping only for six months or more and what strops they use and how they're set up.

Originally Posted by honedright

Joe, you say there is some type of abrassive on my strop, but where did it come from?? I certainly haven't applied any paste or abrassive in the ten years I've been using it. And I've cleaned and dressed this strop many times over the years. It would seem that any paste that could have ever been on the strop would have been removed long ago or reduced to an ineffective amount.

Or, are you suggesting that horse hide cordovan strops are more abrassive than cowhide? That could be so, but I don't know.

Also, I do about 20-30 round trips on both linen and leather before each shave. Isn't this the standard number for most users?

It would be interesting to hear from others who use the Dubl-Duck strops.

Scott

Scott, what do you dress your strop with? THe dressing might contain some abrasive ingredient or a chemical that reacts with the leather and produces an abrasive surface on the leather.

Originally Posted by Joe Lerch

I don't know. I'm just saying the slight abrasive has to be there. You mentioned putting on some uretahne and sanding it. Maybe that's enough. The abrasiveness required for 40 reps would probably be finer than a .025 micron (notice the decimal point) abrasive.

Regarding the urethane (highlighted quote above), you're confusing strops. There is no urethane on my daily strop. My daily strop is the Dubl-Duck - no urethane, no abrassive pastes, just skill.

Originally Posted by Joe Lerch

Also, I do about 20-30 round trips on both linen and leather before each shave. Isn't this the standard number for most users?/QUOTE]We had an experiment here that showed more than 60 made no difference (in terms of stropping only), and 45 seemed to be the sweet spot.

It would be interesting to hear who maintains their razor with stropping only for six months or more and what strops they use and how they're set up.

You've already heard from one person (yours truly) "who maintains their razor with stropping only for six months or more and what strops they use and how they're set up."

Since my bringing this topic up, it seems that the above is a new concept for many. Not enough time has passed for most to put in the time and practice required to achieve the results that I've had. I think very soon though, you will start to hear from other SR users who are getting better shaves and going longer between honings now that they know it is possible.

Scott