So I'd like to make a leather belt sheaf for my new knife
http://slinging.org/forum/YaBB.pl?num=1381591178

But I've only got soft leather. Plus I'd prefer to stitch this one so hardened leather is essential.
Presumably there's a process for hardening leather.

Is it as simply as wetting the leather and then drying it out ? or is it more complex than that.

Also can I make the sheaf and then harden it as one piece or do I have to harden it first and then use it ? (ie: will it shrink noticeably)

First of all make a wooden copy of the blade with the same measures.
Then boil some water and add large salt with the proportion of 1 spoon each glass of water. Once it boils drop the water on the leather using a spoon. When the sheath darkens put the wooden blade inside and let it dry in a ventilated, shaded place.
Put salt in abundance and wait for the sheath to gain its original color.
This is my recipe, it worked well on my leather but it could need slightly changes with different leather, so test it on a waste before trying it on the sheath  :)
Greetings,
Mauro.

And I was wrong, it's better if the wooden blade is slightly smaller than the steel one, like 1mm smaller.
Greetings,
Mauro.

salt - even with stainless steel I wouldn't want to have a salt impregnated sheaf.
problem is if it gets wet - you have an electrolytic reaction which probably bypasses stainless steel's anti-oxidation protection.

Even stainless steel rusts in salt water.

Anyone got a no-salt alternative ?
Like the wooden model for forming though, I'll make one of those :thumb:

Oh yeah I do have a temperature adjustable excalibur dehydrator. I was thinking I could dry anything off in that pretty quick.

Is there any disadvantage to 'cooking' the leather beyond a certain temperature ? 

Wax. You can dip it in boiling wax. It fills in the pores of the leather without drying it out like I imagine salt water would. Also if you get your hands on some thin plastic sheeting use it to line the inside of the sheath. It will protect the leather from the blade and stiffen it up too :)

Or simply hot water, not even boiling. It will harden your leather while keeping it supple. When the leather stop bubbling, get it out of the water and let it dry on shape.
Then, you can waterproof it however you want.

That kind of leather will not 'harden' per se and any kind of process proposed here will not last. If you want stiff use rawhide or a rawhide split in the construction or better yet use a 6-8 oz oak tanned leather. Oak tanned leather once cased and worked will retain its shape. Stiffness in leather is dependant on the type of tanning process and thickness.

I have found that to stiffen and render more durable deerhide, take a block of bees-wax, and rub it onto both sides. then take a small alcohol burner(i made one by filling a 9mm shell with rubbing alcohol) and gently heat the leather enough to melt the wax and let it soak in. It doesn't look super pretty, but man, it works!

squirrelslinger wrote on Oct 24^th, 2013 at 5:00pm:

I have found that to stiffen and render more durable deerhide, take a block of bees-wax, and rub it onto both sides. then take a small alcohol burner(i made one by filling a 9mm shell with rubbing alcohol) and gently heat the leather enough to melt the wax and let it soak in. It doesn't look super pretty, but man, it works!

Until you're somplace warm then it get's soft again.

nope, it doesn't soften if you heat it to 100 degrees, nor does it soften in water.
It does soften at 150 though
it easily becomes like wet leather at 190

Ya on second thought, do what Pikaru says if this is something you want to keep C.A.
You could get a scrap of leather and experiment with it too. See how you like the results for yourself

cuir boulli is a technique of hardening leather that goes back to at least the Middle Ages
good tutorial at
www.jeanturner.co.uk/static-contents/tutorials/CuirBoulliTechnique.pdf

Now that I think about it, none of my blades got rusty by being sheathed on a leather sheath hardened with water and salt.
But you could prevent the blade from getting rusty by lining the interior of the sheath with raw natural wool.
Also smoothing the blade with pumice keep it rust-free  :)
And I only forge recycled iron!
Greetings,
Mauro.

Once i've read that only vegetable tanned leather can be boil hardened.

Quote:

1. The Technique of Water-Hardening Leather. Vegetable tanned leather is initially soaked in water for long enough to wet it through completely. This takes approximately 10 minutes. If the soaked leather is then placed in a pot of water which has been pre-heated to 180 ̊ C, it will begin to change in shape and texture. After approximately 60 seconds, the leather dark ens, goes limp and begins to curl up. If extracted at that stage, it will have shrunk a bit, thickened slightly, and still be able to be stretched, such as a sheet of rubber. At this stage - it is possible to stretch and form the leather into required shapes. After a minute or two, the stretchiness goes away, however, the leather will still be fairly flexible. After air-drying for a few hours, the leather becomes increasingly stiff, thickens slightly and becomes harder. The longer the period of time that the leather is left in hot water, the more it shrinks, the darker it gets, the thicker it becomes, and the harder the finished product is. Sufficient time in hot water will render leather into something which resembles wood, however, as with most natural things, the process does have a tr ade-off, in that the ha rder the leather, the more brittle it becomes. In the case of actual armour, it is likely that the leather would have been hardened to the maximum, and replaced after every battle. For purposes of re- enactment or the making of object d-art - it is desirable to harden the leather without detracting from it’s strength. Approximately 30 seconds of immersion is usually sufficient to harden leather to a suitable state - where the leather is hardened but still flexible - and results in a shrinkage of approximately 1/8 th the original size (i.e. the finished article will be 7/8 th the size of the original) and an increase in thickness of approximately 25%. Due to the fact that the process is very temperat ure sensitive, it is advised that an accurate thermometer is used. To a certain extent, the finished product will also be dependant on the leather itself, and experimentation with scrap leather is recommended. While being guided by the clock, allow yourself to learn how the different types of leather behave and work according to the changes you observe during th e process as it proceeds in order to achieve the end result you desire. The Cuir Bouilli process can be considerably shortened by the use of boiling water. Thirty seconds of immersion in boiling water will result in a shrinkage to 7/8 th of the original size and 40 seconds immersion in boiling water results in a shrinkage to 2/3 rd of the original size and approximately doubles the thickness of the original leather. The use of boiling water has the advantag e of speed and removes the need for a thermometer, however it does hold two distinct disadvantages, viz. the process is harder to control, and secondly, the hotter water result s in a less uniform hardening process. Patchy softness or brittleness can caus e surface cracks to develop over a period of time, and makes the lower temperature process more desirable when producing items intended for long-term use or as items of art/functionality.

so how do I know if my leather has been vegetable tanned or not - and what kind of vegetable tans leather ?

seem simple enough - except for the part where it says to heat water to 180C - this isn't actually possible water only get to 100 and then it turns to steam :-)
So we'll just substitute - 'boiling water' for that part, I think.
Actually she probably meant 80c - hence the later reference to a thermometer and boiling water being much quicker.

anyway seems simple enough to try a few scraps of the leather I have and see what happens. Sounds like what I'm after though.

C'mon C_A, that's 180 Fahrenheit. Water boils at 212 degrees in that system, so boiling would be a bit too hot. The equivalent Celsius would be 82.

yeah but given that fahrenheit was based on a bucket full of ice, water and salt and mrs fahrenheits armpit temperature.

I'd rather stick to celsius - makes a lot more sense :-)
And it does say C not f in the article.

And as the components I'm waiting for haven't arrived yet and work is very slow this week - I've got some time, so play this afternoon. So I'll test the leather I've got and see what happens :-) 

Curious Aardvark wrote on Oct 30^th, 2013 at 8:51am:

yeah but given that fahrenheit was based on a bucket full of ice, water and salt and mrs fahrenheits armpit temperature. I'd rather stick to celsius - makes a lot more sense :-) And it does say C not f in the article. And as the components I'm waiting for haven't arrived yet and work is very slow this week - I've got some time, so play this afternoon. So I'll test the leather I've got and see what happens :-)

Not about to argue over which system makes sense. Ours is handy, as a 100 degree day is very hot. If the article said it was 180 Celsius they must have had the leather in a pressure cooker or they meant Fahrenheit.

Curious Aardvark wrote on Oct 30^th, 2013 at 8:51am:

yeah but given that fahrenheit was based on a bucket full of ice, water and salt and mrs fahrenheits armpit temperature.

Both Fahrenheit and Celsius were based on the freezing and boiling points of water. The scale you're talking about was never adopted.

When I tried boiling leather, I kept it simple. If bubbles were coming up in the water, and it was hotter than hell, it was boiling. When the leather curled, it was time to pull it out and shape it.

But I'm kind of remedial that way. :D

Well I've just bought a water bath fr sous vide cooking experiments (really really want to make scotch eggs with liquid yolk centres).

So i now have a reasonable sized container of water that i can accurately set to any temperature :-)
http://www.amazon.co.uk/Zyon-Premium-Sous-Water-Cooker/dp/B010671LE0/ref=sr_1_1?ie=UTF8&qid=1452600037&sr=8-1&keywords=sous+vide

lol it's gone up by £4 since i bought mine a few days ago  :-)

So I'll probably have ago at the leather hardening thing fairly soon :-)


Quote:

Both Fahrenheit and Celsius were based on the freezing and boiling points of water. The scale you're talking about was never adopted.

oh really ?
How do you account for the fact that 100f is the body temp of a hot (metabolically) woman then.
Or the fact that every single account of fahrenheit states that it's based on his wifes armpit temperature :-)
Or indeed why 0 fahrenheit is NOT the freezing point of water but a good bit lower.

There's no way it's based on anything as sensible as the freezing and boiling of water. If it were - we'd call it the celsius system :whistle:

I've gained a bit of experience in this matter since last time I read this thread. So yes, Pikaru was right you need veg tan leather to mold and case it. Another name for it is tooling leather.
So you can submerge you tooling leather til it doesn't bubble and then formxit with you're fingers around your knife. You can use a smooth handled brush or something similar to help you gain definition. That part is called boning.
Wrap your knife in a few layers of seran wrap to keep it dry.
The hotter your water, the harder your leather will "case". Essentially, the really hot water changes the actual chemical composition of the leather by melting the collagens in the leather.
And it doesn't have to be super hot to retain its shape.
I'll do a quick video tonight for ya