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How to create some convexity when making a strop

@Clay S, I don't see how that convexes the strop at all. The strop normally attaches to the straight bar of the D.
The center of the "straight" part is tighter, because it is closer to the curved part of the "D" than the legs. Then, when the center of the curved part of the "D" is pulled, the legs will go upward. This will make a concaved Surface, then flip it over. The "D" is upside down in my photo and drawing. Just trying to explain it as shown.

The formerly straight part of the "D" closest point to the curved part should be where the line demarcating the bend of the "D" should run. I'll try to bend something with clearer, tighter radius bends, and perhaps a stretchable strap to see how it moves.
 
Here's a question for Slash McCoy. Your technique is to use a round file to very slightly widen the outer two of the three screw holes. What I like about that idea is that it seems more permanent than bending the D rings. As we pull on the strop, the D ring might eventually be pulled straight again. But hole position is permanent.

Also I suspect that the bent D ring method would induce bend at the ends but perhaps not along the whole length. Whereas the hand cupping and sliding technique covers the whole strop.

But Slash, I don't understand the mechanics of why widening holes translates into convexity. I get how your straight D ring would now pull hardest in the middle. (and wow it would be so easy to overdo this widening and ruin the strop) But a more taught middle could flip downwards into a cup. Or are you also using a your free hand to force the slack sides downward and induce convexity that way?

I am sorely tempted to try Tony Miller's method. Take a real big wide piece of leather, the width of five or six strops, wrap it into a tight circle nine inches across and leave it for a couple months until the whole leather has bowed outward, creating a permanent slight convexity.

No wonder his strops are so well liked. It's a brilliant idea for large scale manufacturers.

Hey, maybe a few of us should try that together. One of us buys a big piece, wraps it and then months later, cuts it and ships it out to three others.


Thanks
 
Oh hey, the coffee is kicking in and I just realized something. Tony Miller sells a travelling strop. It rolls up tight in a round case. We all strive to do the opposite, to keep our strops flat, but he goes the opposite way. It's because he rolls his leather up in the first place. Done right, rolling up actually helps maintain the desired convexity.
 
Here is the bent D ring.
DSCN1996.JPG
 
Ok Bluesman, so it looks like the straight part of the D is bent so it points toward the other end of the strop. Is it also bent upward?

And is there a second bent D ring at the bottom of the Strop?

And did this induce convexity all the way down the length of the Strop? Or mainly at the ends?

Also I just made my first strop. Have a look at the posting about Pete the saddlemaker
 
Better "D ring" and bends "Wrapped" wire is where the chain/swivels would be hooked. It would take a while to figure how much to bend what, and jigs instead of my hand and a Leatherman. Having one on each end should get it to go the entire length, or one end and hand cupping it on the other.

WIN_20181227_20_20_14_Pro.jpg
WIN_20181227_20_29_17_Pro.jpg
 
Ok Bluesman, so it looks like the straight part of the D is bent so it points toward the other end of the strop. Is it also bent upward?

And is there a second bent D ring at the bottom of the Strop?

And did this induce convexity all the way down the length of the Strop? Or mainly at the ends?
It is only bent upward.

The other end has a sewn on handle. I generally held it just above the handle barber end style.

If you can shape both ends convex the center follows.
 
I've just built my first strop. I didn't bend the D ring, but since I used chicago screws, I could unscrew it and bend the ring up and then reassemble it.

I'll see how it goes first.
 

Tony Miller

Speaking of horse butts…
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?

The decorative line is mainly that, decorative but the tool that creates it imparts a slight rounding of the corner which I feel is less likely to catch the razor and nick with a careless stroke. A sharp square edge looks nice too showing the full thickness of the leather but tends to nick easier in my opinion.
 
The decorative line is mainly that, decorative but the tool that creates it imparts a slight rounding of the corner which I feel is less likely to catch the razor and nick with a careless stroke. A sharp square edge looks nice too showing the full thickness of the leather but tends to nick easier in my opinion.

Thanks for the explanation Tony.
 
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