How to create some convexity when making a strop

[kohalajohn]

Slash McCoy has talked about this, so I'm hoping he'll give his two cents.

I'm about to make my first strop. In talks with Tony Miller, I've come to desire a small amount of convexity.

Slash has said that the advantage of using three screws is that if one's strop starts to cup, one can every so slightly open up the two outside screws, while keeping the middle one tight.

If that can reverse a cupping, perhaps it can be used to induce slight convexing right at the build time?

Ideas appreciated.

 

[Doc226]

Barber ends-when you grab the strop it naturally tends to have a convexity

 

[Alum of Potash]

Barber ends-when you grab the strop it naturally tends to have a convexity

Depends how you grab it though. You have to grab it so that the cup is convex, since you can also grab it so that the cup is concave.

 

[kohalajohn]

Yes to that. Although the natural grip, with the back of the hand facing up, automatically induces convexity.

I just wonder if how I set my chicago screws will have an effect.

Maybe this is real simple. I just put a D ring and three chicago screws on the top and leave the bottom alone, just a barber end. Slide my hand down from the top, to give it a tiny bit of oil from the hand. And the slide down undoes any tendency to cup. And at the bottom, my barber end grip forces a slight convexity.

 

[Alum of Potash]

Yes to that. Although the natural grip, with the back of the hand facing up, automatically induces convexity.

Sorry to belabor the point, but not necessarily. I recently watched an expert grabbing the bottom of his 3"+ wide strop like a barber's end with the back of the hand facing up, ignoring the D-rings entirely, and yet he was gripping it in such a way that the bottom of the strop had a concave bias. I asked him about this, and he replied that, yes, he had grabbed it in the wrong way, and that introducing a convex bias would have been better, but that it didn't matter in the end as the stropping area was further up and unaffected (which more or less was true in this case).

 

[Doc226]

If you stand to the side, grab the bottom end of the strop (barber ends) with the palm facing down so that knickers face the ceiling I don’t think you can do anything but convex the strop.


Sent from my iPhone using Tapatalk

 

[kohalajohn]

Doc if my knickers are facing the ceiling, that means I'm doing something even more fun than stropping.

 

[kohalajohn]

But seriously.

The barber end technique is not bad. I've done it, just grabbing the strop above the bottom D ring. Yes, I can see you can do the squeeze wrong and accidentally cup it, but if you think about it, it's pretty easy to induce convexity with your grip.

The problem is that you get huge convexity at the bottom half and nothing at all in the top half.

I want to recreate what Tony Miller does. Somewhere, and I can't find it now, Tony Miller said he makes his strops with a tiny amount of convexity built into them. At the time I thought the leather itself was somehow carved or shaved that way. But now I'm suspecting that there's some clever technique with how you fold over the ends and tighten them down with three chicago screws.

If that's right, then I'd love to do it. If nothing else, it would permanently block the dreaded cupping.

 

[bluesman 7]

I remember convexing the top D-ring on one of my strops. Hasn't been much of an issue for me for a while. I usually grab the bottom as a barber end regardless of how the strop terminates.

 

[bluesman 7]

Ok I just shaved and paid attention. I grab the strop with my thumb on top and my index finger forming an arc under the strop.

 

[Alum of Potash]

I want to recreate what Tony Miller does. Somewhere, and I can't find it now, Tony Miller said he makes his strops with a tiny amount of convexity built into them. At the time I thought the leather itself was somehow carved or shaved that way. But now I'm suspecting that there's some clever technique with how you fold over the ends and tighten them down with three chicago screws.

As I recall, Tony Miller's strops have a decorative line incised along the lengths of the strop. I wonder if that might not help to relieve the strop from cupping. Similarly, there are some old-style barber's end strops with a diamond-back incised patterning on the backside. Perhaps this too was to relieve the strop from cupping?

 

[stone and strop]

As I recall, Tony Miller's strops have a decorative line incised along the lengths of the strop. I wonder if that might not help to relieve the strop from cupping. Similarly, there are some old-style barber's end strops with a diamond-back incised patterning on the backside. Perhaps this too was to relieve the strop from cupping?

Alan I believe this incising was exactly for this reason. It will always lay perfectly flat. On the front it says "makes it extra soft"
This also gives the strop a very supple feeling.
Back

Front

 

[Alum of Potash]

Thanks Paul.

 

[mrlandpirate]

I force a bow across the width by pressing both edges with my thumb and finger tips and slowly run my hand down the strop once or twice. Every day or two keeps it where it needs to be. I prefer a very slightly convex surface myself.

this was from Tony Miller on another strop thread

 

[Clay S]

But seriously.

The barber end technique is not bad. I've done it, just grabbing the strop above the bottom D ring. Yes, I can see you can do the squeeze wrong and accidentally cup it, but if you think about it, it's pretty easy to induce convexity with your grip.

The problem is that you get huge convexity at the bottom half and nothing at all in the top half.

I want to recreate what Tony Miller does. Somewhere, and I can't find it now, Tony Miller said he makes his strops with a tiny amount of convexity built into them. At the time I thought the leather itself was somehow carved or shaved that way. But now I'm suspecting that there's some clever technique with how you fold over the ends and tighten them down with three chicago screws.

If that's right, then I'd love to do it. If nothing else, it would permanently block the dreaded cupping.

Bending a "D" ring where the straight part actually bends inward slightly would create more tension in the center, which would force a curve. Bending the "D" ring between the Arcs ( Backwards, as closely as I can emulate, "CI", between the letters is where it is bent)would force it to go one way or the other. Make two of these rings. for each end, forcing the leather the same way.

 

[bluesman 7]

I bent the top and bottom of the D towards the back side of the strop. Bend would be horizontal in orientation shown.

 

[Clay S]

I bent the top and bottom of the D towards the back side of the strop. Bend would be horizontal in orientation shown.

Sounds like that might do it as well. I'm just trying to imagine the reaction to the bending. Haven't tried it.

 

[kohalajohn]

Clay and Bluesman, I'm not clear on visualizing what you're describing.

If you lay the D flat on table. And you bend the straight part so that it is convex. That is, the straight part now has a belly that is pointing up toward the ceiling.

Is that what you mean?

Clay and Slash talk about pulling the middle of the strop tighter. Clay by bending the straight part toward the curve. Slash by slightly filing out the two outside screw holes, leaving the middle screw tight.

But I dont see how making the center more taught would cause convexity. That could just as easily cause the center of the strop to flex downward. Maybe if you also slid a cupped hand down it every morning, to induce convexity, the tighness of the center would ensure that convexity would remain in place.....?

 

[bluesman 7]

Clay and Bluesman, I'm not clear on visualizing what you're describing.

If you lay the D flat on table. And you bend the straight part so that it is convex. That is, the straight part now has a belly that is pointing up toward the ceiling.

Is that what you mean?

Yes that is what I did. I don't even remember which of my strops I did this on, I'll have to see if I can find it. As I remember it did work, though I never repeated it on any other strops.

 

[Clay S]

Clay and Bluesman, I'm not clear on visualizing what you're describing.

If you lay the D flat on table. And you bend the straight part so that it is convex. That is, the straight part now has a belly that is pointing up toward the ceiling.

Is that what you mean?

Clay and Slash talk about pulling the middle of the strop tighter. Clay by bending the straight part toward the curve. Slash by slightly filing out the two outside screw holes, leaving the middle screw tight.

But I dont see how making the center more taught would cause convexity. That could just as easily cause the center of the strop to flex downward. Maybe if you also slid a cupped hand down it every morning, to induce convexity, the tighness of the center would ensure that convexity would remain in place.....?

Below is how I am talking about bending the straight part. The dotted line is where I would bend the "D", if it where lying flat, toward the ceiling. Then when pulled, the two legs of the "D" would try to go upward, the center would remain in the same place


A paperclip I tried to bend like I want: