Leather Quality and Properties



Fang66 said:

liquids and gases behave differently when faced with a semi-permeable membrane.

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I'm sure that's true. And again I am not chemist so anyone who is feel free to correct me.

That said, aside from the effects of heat and/or gravity, water in both liquid and vapour states share one commonality--they both tend to abhor areas that have lesser concentrations of moisture. IOW, both water and vapour will move to spaces that are dry or drier. Liquid water...even ice...will evaporate, no heat needed--it is water trying to take over the world.

Whether that's good science or not, it is both observable and demonstrable....and practically speaking the only consideration that bears on the discussion of silicones, oils, waxes and waterproofing leather.

DWFII said:

Fang66 said:

liquids and gases behave differently when faced with a semi-permeable membrane.

Click to expand...

I'm sure that's true. And again I am not chemist so anyone who is feel free to correct me.

That said, aside from the effects of heat and/or gravity, water in both liquid and vapour states share one commonality--they both tend to abhor areas that have lesser concentrations of moisture. IOW, both water and vapour will move to spaces that are dry or drier. Liquid water...even ice...will evaporate, no heat needed--it is water trying to take over the world.

Whether that's good science or not, it is both observable and demonstrable....and practically speaking the only consideration that bears on the discussion of silicones, oils, waxes and waterproofing leather.

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"both water and vapour will move to spaces that are dry or drier"
This is true, but their ability to do so, and the rate that they do do so will vary. Even so water vapour inside a shoe will tend to condense anyway so in this context the point is mostly moot. Also for most footwear getting moisture out of the shoe is a bigger issue than stopping it getting in, I don't waterproof any of my shoes or boots, except a pair of tactical boots that I use for hiking. Then again I stay indoors when the weather is foul.

But regarding your original question, "If they are applied to keep water out, how can they help but keep water in?", many waterproofing compounds tend to mostly act by forcing water to bead up and thus roll off the surface, if you break the surface tension of the beads and allow them to sit on the surface the water will soak in, this beading action does not occur when the water transfers from the non-coated side. The water will transfer from the more moist inside to the less moist outside and then evaporate as water vapour (wicking). These waterproofing treatments will interfere with this process to a certain, but generally not significant, degree.



Fang66 said:

The water will transfer from the more moist inside to the less moist outside and then evaporate as water vapour (wicking). These waterproofing treatments will interfere with this process to a certain, but generally not significant, degree.

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I understand your explanation. I'm not sure I agree with it...or better way to say it--that's not consistent with my experiences.

I use conditioners such as Lexol and Bick4 to inhibit drying during crimping and lasting. Because if drying happens too fast, water staining can occur.

Neither of those products contain much in the way of oils, yet they still inhibit evaporation from the inside to the out.

Well... practical experience aside I'm getting out of my depth so...I'll leave it at that.

Fang66 said:

But regarding your original question, "If they are applied to keep water out, how can they help but keep water in?", many waterproofing compounds tend to mostly act by forcing water to bead up and thus roll off the surface, if you break the surface tension of the beads and allow them to sit on the surface the water will soak in, this beading action does not occur when the water transfers from the non-coated side. The water will transfer from the more moist inside to the less moist outside and then evaporate as water vapour (wicking). These waterproofing treatments will interfere with this process to a certain, but generally not significant, degree.

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Good explanation and entirely consistent with my experience.

DWFII said:

Fang66 said:

The water will transfer from the more moist inside to the less moist outside and then evaporate as water vapour (wicking). These waterproofing treatments will interfere with this process to a certain, but generally not significant, degree.

Click to expand...

I understand your explanation. I'm not sure I agree with it...or better way to say it--that's not consistent with my experiences.

I use conditioners such as Lexol and Bick4 to inhibit drying during crimping and lasting. Because if drying happens too fast, water staining can occur.

Neither of those products contain much in the way of oils, yet they still inhibit evaporation from the inside to the out.

Well... practical experience aside I'm getting out of my depth so...I'll leave it at that.

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I don't doubt that they do, especially when freshly applied, they are not however waterproofing products, or certainly not DWRs.

^Awesome first post!

So I understand how scotch grain is a form of correction, but what is it really that gives it the texture? It is a stamp on the leather, correct? Does anybody have a picture of such a method in the process?



patrickBOOTH said:

So I understand how scotch grain is a form of correction, but what is it really that gives it the texture? It is a stamp on the leather, correct? Does anybody have a picture of such a method in the process?

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It's embossed.

Rollers, plates? Don't know. Could be dependent on tannery.

The hides themselves are usually a little thicker and can be superficially scarred --the embossing will cover that.

Yeah, this is probably why it seems to be a bit more water repellant than regular calf. All of the pores are sealed up.

These are the boots I mentioned up thread. I bought them in 1994. I just put another coat of Nikwax on them, which is why the laces are out.

Is the whole of an animal made use of before their skin is made into leather? Do we eat the steak as well as harvest the leather?

Leather is a by-product of the meat industry. Tanneries don't receive carcasses of whole animals, just the skins.



Munky said:

Is the whole of an animal made use of before their skin is made into leather? Do we eat the steak as well as harvest the leather?

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In the case of farm animals, yes. Leather is a byproduct of the meat industry for things like cow, pig etc so from an ethical point of view a calf didnt die to make your wallet, it died to make your burger or stake and the wallet is a nice bonus. Exotics may be different though

Charlie

Allegedly in the past animals were raised for their hides, which is why older, vintage shoes and such were such better quality and have lasted.