How to “harden” leather?

[John Spartan]

And I know little about leather so forgive me if this is a stupid question.
Acquired some leather for free that is quite soft and supple I think, by feel, by the use of oil…?
Have some flintlock related projects I’d like to try with it but a stiffer leather would be nicer. Doesn't have to shave wood but a little stiffer would be ideal.
Is there an easy way to do this?
EDIT: Grammar

 

[tenngun]

Warm it and then paint with bees wax.
Can make it so hard it will shatter if you want

 

[DiMarco_Mercantile]

I know that when it comes to making shoe soles, you can achieve a good hardness by soaking a piece of leather in water then pounding it with a mallet while wet. When it dries, it’s quite stiff. This may be overkill for what you’re looking for though, just thought I’d throw it out there.

 

[Trapper Scott]

Water/heat and pressure. I have had good success with wetting the leather/ soaked and applying constant pressure/working by hand and a heat gun. It will get pretty stiff. Work the leather until you achieve the proper form your after and use the heat gun to rapidly dry it. I've made several leather knife holsters using this method.

 

[John Spartan]

Perfect!
Thank you gentlemen!

 

[Flint Striker]

I’ve done it by heating the leather in the microwave for 10 - 20 seconds at a time, then rubbing in thin slivers of beeswax. In my experience, sno-seal doesn’t seem to harden leather up the same even though it contains beeswax. It takes pure beeswax hours to harden, but once it does it’s almost like kydex.

 

[Tumbledown]

Is it vegetable tanned (ie tooling leather), or chromium? If the former, you can dampen it with a sponge, then mold it by stretching and contouring while wet. It will harden somewhat as it dries, even more so if you burnish it to compress the fibers. If you soak it in near-boiling water for 30-60 seconds, it will get quite pliable, and dry to a hard shell, to the point of being brittle if overdone.

Once dry, it can be stained and finished with wax or a bit of oil (too much will soften it some.)

 

[user 48702]

There's really no way to stiffen soft leather for use as an item or product which is required to have some stiffness or body to it, such as holsters, scabbards, saddles, and you get the idea, these items need to start out as leather with moderate stiffness or temper. You can wet leather, lay it out in the sun and let it dry, or let it dry on its own. Sure it will be stiff or in most cases stiffer than what is was, but once you put it under stress, or bending it back and forth, it will be soft and supple again. It would be good to know the type of leather you have, i.e., vegetable tanned, chrome tanned or alum tanned. Each type of leather tannage is tanned toward a general range of uses, such as upholstery, bag, garment, footwear, saddlery and harness, and each tannage has its own sub-group. When I order a specific tannage, sometimes the tanning is not the correct temper and ends up being too soft with too much stretch. I was told several times, over the years if I could correct a softer tannage into a leather with more temper and reduce stretch, I would be a millionaire overnight.

I have been working with leather for over 50 years, 33 of those years professionally as a leather manufacturer, and produce a wide variety of WWI and WWII accoutrements, as well as several items for military and law enforcement. If you want to contact me via PM, I will send you my company phone number, give me a call and I'll help you any way I can. I also have contact info in my profile.

Richard

 

[John Spartan]

Based on looks alone, comparing it to my other known stuff, I think its vegetable tanned. It is thick like a good sturdy belt.
And I mightily appreciate the offer Richard but my experience level with leather is minimal, though I like to think of myself as handy, and I planned nothing fancy or taxing. My idea was to warm up with some hammerstalls then graduate to cows knees. Anything more complicated then that I think I’d better leave it to the pros!

 

[GYJ]

Once it's soft from too much oil, there is no fixing it.

 

[Brokennock]

And I know little about leather so forgive me if this is a stupid question.
Acquired some leather for free that is quite soft and supple I think, by feel, by the use of oil…?
Have some flintlock related projects I’d like to try with it but a stiffer leather would be nicer. Doesn't have to shave wood but a little stiffer would be ideal.
Is there an easy way to do this?
EDIT: Grammar

If you are more specific about what your projects are, we could possibly give you more thorough advice. What the project is might determine how stiff you need it, how to stiffen it, and when to stiffen it.
As someone else mentioned, some leathers are never going to wet mold and get stiff. Maybe a picture of what you have to work with?

 

[Brokennock]

Based on looks alone, comparing it to my other known stuff, I think its vegetable tanned. It is thick like a good sturdy belt.
And I mightily appreciate the offer Richard but my experience level with leather is minimal, though I like to think of myself as handy, and I planned nothing fancy or taxing. My idea was to warm up with some hammerstalls then graduate to cows knees. Anything more complicated then that I think I’d better leave it to the pros!

I wrote the above having missed what you said about hammer stalls and cows knees. I have a fever and I'm not thinking clearly.
Neither of those items needs to be stiff.
My hammer stalls are made with a deer skin back and a veg tan front. The deerskin is stretchy and fits over the rounded shape of the frizzen's back, and the veg tan is tough, protecting from the flint cutting through and contacting the face of the frizzen.
My cow's knees are about 4oz deerskin. Easy to fold/roll up, and stash away when not needed.

 

[John Spartan]

Once it's soft from too much oil, there is no fixing it.

Now this is interesting. Guess I always thought of leather like a more complex fabric. It may stain like fabric but oil can be, at least partially, removed and then “toughened” up by the above methods.
Well I am kind of the original “mad scientist” in these matters and not afraid to try some ideas. Keeping in mind there are degrees of everything lets see how right you are!

 

[andy52]

Ancient leather armor was shaped wet and then coated with lacquer. When I make Ridgid ball bags I wet the leather then heat it in an oven at about 250 until it's dry, it becomes pretty hard.

 

[1971fx]

Hang it in your barn for 75 years these were in a very old barn recently taken down full plow rigs with hames and collars

 

[Robby]

Heres' a few options.
https://mazeleather.com/4-ways-to-harden-leather/Good luck!!!!
Robby

 

[John Spartan]

Thanks for the additional.
I’ve found about 4 or 5 methods for removing oil from leather from the, always reliable and trustworthy, internet from easy and safe (warm water and Dawn) all the way to harsh (acetone) so we have a few things to try before hardening.

And in all this reading - and looking at my own personal leather - I now wonder if I OVER oil my leather with my usual neatsfoot. Besides losing hardness and shape is it possible for leather to be TOO oiled like a strap or something?

 

[1BadDart]

Hang it in your barn for 75 years these were in a very old barn recently taken down full plow rigs with hames and collars

The stories those could tell!

 

[B P Arn]

See post #8 again. Great info.

 

[user 48679]

And in all this reading - and looking at my own personal leather - I now wonder if I OVER oil my leather with my usual neatsfoot. Besides losing hardness and shape is it possible for leather to be TOO oiled like a strap or something?

FWIW, John, I've learned to never oil my leather goods - I just apply a renewable light coat of clear shoe polish to protect it from mold/verdigris.