Leather Quality and Properties

[DWFII]



Interesting. I thought I saw a photo that had blades that twisted along a cylinder. Of course those are blades and not a "grit", so my use of the word "grinding" might not be accurate.

That's a possibility. I vaguely remember seeing a machine like that in a big warehouse of shoe machinery in LA...I was buying a sewing machine.

But you're right--a cutting or even scraping action is quite different from a grinding action.

 

[Equus Leather]



Interesting. I thought I saw a photo that had blades that twisted along a cylinder. Of course those are blades and not a "grit", so my use of the word "grinding" might not be accurate.

I think you might be thinking of a skiver that has a bell knife. It's still using one knife but it's curved because it's principally designed to thin a tapering narrow section of an edge

Charlie

 

[DWFII]



I think you might be thinking of a skiver that has a bell knife. It's still using one knife but it's curved because it's principally designed to thin a tapering narrow section of an edge

Charlie,

I have two Bell skivers myself.

But I'm sure you know that the bell skiver is a little bit of a Johnnie-come-lately. The Amazeen (Carter?) skiver was invented in the early to mid 19th century. and rather than have a cylindrical knife the knife was a flat spinning disc.

I had an opportunity to buy one of these (I wish I had) early on in my career but I was looking for a working machine and this one was too much of a gamble.

That said, skiving machines are seldom good stand-ins for splitting machines. I have used my Fortuna for splitting...in a pinch...but the results are problematic and have to be leveled by hand.

In that warehouse I mentioned above (Melanie Machine) I was shown half a dozen splitting machines when I inquired. Most, if not all of them were band knife based.

The machine that Horns refers to may have been a fleshing machine. That said, my memory of it is very vague...maybe even a figment.

 

[Equus Leather]



Charlie,

I have two Bell skivers myself.

But I'm sure you know that the bell skiver is a little bit of a Johnnie-come-lately. The Amazeen (Carter?) skiver was invented in the early to mid 19th century. and rather than have a cylindrical knife the knife was a flat spinning disc.

I had an opportunity to buy one of these (I wish I had) early on in my career but I was looking for a working machine and this one was too much of a gamble.

That said, skiving machines are seldom good stand-ins for splitting machines. I have used my Fortuna for splitting...in a pinch...but the results are problematic and have to be leveled by hand.

In that warehouse I mentioned above (Melanie Machine) I was shown half a dozen splitting machines when I inquired. Most, if not all of them were band knife based.

The machine that Horns refers to may have been a fleshing machine. That said, my memory of it is very vague...maybe even a figment.

Hi DW,

I have never come across a fleshing machine so I will take your word for it! I have also never seen a non band knife mechanised splitter, though saddlers often just use bench mounted fixed blade single roller machines for either strap splitting or taper skiving strap ends where heavier leather is being used

Charlie

 

[HORNS]

Thanks, guys. What is this machine here?

 

[traverscao]

Thanks, guys. What is this machine here?

That's for shaving the shells after currying or something.

 

[DWFII]



Hi DW,

I have never come across a fleshing machine so I will take your word for it! I have also never seen a non band knife mechanised splitter, though saddlers often just use bench mounted fixed blade single roller machines for either strap splitting or taper skiving strap ends where heavier leather is being used

Shoemakers...bespoke makers...to the extent that they use a splitting machine, use something similar to what saddlemakers use. The guy who taught me to make saddles had both--the kind the shoemakers use, with a double roller and the kind in your photo.

That said, I did find this video on Youtube that appears to function as Horns described.

 

[DWFII]

Getting back to the original discussion regarding Cordoba and cordovan, I have further communications from my particular friend. If I can get attribution and permission I will quote it but fundamentally it says that one of the earliest mentions of equine leather is from the mid 19th century: H. Dussauce, A New and Complete Treatise on the Arts of Tanning, Currying and Leather-Dressing; Comprising … Philadelphia: Henry Carey Baird, 1867 for 2nd edition. And that one of the chief uses of the butt was for making patent leather as the fine nap would allow for the even application of linseed oil based, high gloss, finishes.

Previous to that, 18th century French sources state that horse leather is of poor and uneven quality and suitable only for midsoles.

I might add that this is the problem with blogs and the Internet and knowledge that we don't have to exert ourselves to acquire (the main issue I had with this thread when it was started). Everybody has an opinion and even a right to an opinion but in such circumstances "a little knowledge is a dangerous thing."

You can read blogs expounding on this and that ...and some of them are even genuinely trying to be helpful. But like the occasional reader, they are looking for quick and easy answers...after all, they still have all the work of blogging to do after they've done their limited research.

To get the real skinny you have to do the research with an aim towards understanding not just collecting tidbits to impress friends or win at Scrabble. Sometimes this means digging, sometimes it means waiting. Sometimes it means sifting through the spurious. Sometimes it means talking to people who are intimately involved with the work or the history, etc.. Not just amateurs...god bless them.

 

[Equus Leather]



Shoemakers...bespoke makers...to the extent that they use a splitting machine, use something similar to what saddlemakers use. The guy who taught me to make saddles had both--the kind the shoemakers use, with a double roller and the kind in your photo.

That said, I did find this video on Youtube that appears to function as Horns described.

Interesting! Quit impressive being accurate enough to split a piece of paper though wether it splits leather nicely is another thing I guess

Charlie

 

[DWFII]



Interesting! Quit impressive being accurate enough to split a piece of paper though wether it splits leather nicely is another thing I guess

Charlie

Well, you know...one of the things that I have found over the years is that no matter how sharp, a straight blade being pushed through a piece of leather with the blade perpendicular to the line of force will not cut as well as the same blade turned slightly so that the blade is at an angle to the line of force. This seems to provide a rationale for the twisted blade machine in the video.

I've seen that in my splitting machines as well--if I can't get the leather lined up to go through at an angle, I will sometimes...depending on the tanning...have trouble getting it through at all.

 

[bengal-stripe]



Interesting! Quit impressive being accurate enough to split a piece of paper though wether it splits leather nicely is another thing I guess

Those digital splitters are actually amazing (my favourite toy at 'Cordwainer's College'). Depending on the model, they take a width of 40 cm (or more). You press a button to set the required thickness digitally to, let's say 1.8 mm; the leather whizzes through and comes out dead-accurate at 1.8 mm.

As Karajan said (at the launch of the CD back in 1986); "Everything else is gaslight!"

 

[DWFII]



Interesting! Quit impressive being accurate enough to split a piece of paper though wether it splits leather nicely is another thing I guess

Charlie

In the end though, beyond a certain point, dry splitting (splitting after tannage)...no matter how even or accurate...can significantly reduce the tensile strength of the leather. Nick or Skip (can't remember which of them I was talking to about this) at Horween told me that if you have a four ounce leather it is not wise to split it beyond two ounce...if that.

And 3 ounce would be safer.

 

[HORNS]

Very interesting, guys. Thanks for all the effort and information.

 

[patrickBOOTH]



patrickBOOTH, I used to suffer from the same irritating tidbit, but I managed to find a way for removing water spots on shell cordovan. Simply lift the shoe under your mouth, breath out deep, and bull the spot with a metal spoon. The warmth and moisture from your breath will affect the oils and tallow, and the pressure from the spoon will do the rest. Most spots will diminish and disappear easily. It will look and feel weird, but hey, this is Styleforum!

@VRaivio I gave this a shot last night ad discovered something. I don't think your breath has really any effect. I was able to just slightly pit the surface of the wax with my horn shoehorn and get rid of the spots. It almost seemed as if the spot "popped". After that there's obviously a scuff mark, but it polished over easily. Much easier a fix than stripping and rebuilding the finish, so thanks for this advice. It is interesting that it seems there's air or something in there that gets released almost like if you are putting an adhesive label on something and there's an air bubble that if you prick with a needle you can press it down. This brings a new theory to mind as to what these spots are on shell. Perhaps the water swells the shell and when it evaporates the wax finish remains in this swelled position and needs to be pressed back down.

 

[patrickBOOTH]



In the end though, beyond a certain point, dry splitting (splitting after tannage)...no matter how even or accurate...can significantly reduce the tensile strength of the leather. Nick or Skip (can't remember which of them I was talking to about this) at Horween told me that if you have a four ounce leather it is not wise to split it beyond two ounce...if that.

And 3 ounce would be safer.

Late to this conversation, but can leather be also split via sanding the flesh side?