Hardened leather

[carver]

Weavers sell a pour on product to harden soft leather like belly . I haven't used it but have seen it in their catalog . Maybe give them a call and talk about it there is usually somebody around who can give accurate answers . Hot water will make it stiffer on a temporary basis but if it isn't immobilized it will eventually become limber . I have done that on some holsters . I was told by an old timer to dip it in boiling water but have been afraid to try that . But he insisted it wouldn't hurt the leather . I tried drying a piece of scrap in the oven at 300 degrees and it burnt the leather and caused it crack . I only left it in about 5 minutes .I have sandwiched kydex between layers of leather to stiffen up notebooks I made and it worked much better than the traditionally used cardboard .

[Mattsbagger]

6 hours ago, carver said:

Weavers sell a pour on product to harden soft leather like belly . I haven't used it but have seen it in their catalog . Maybe give them a call and talk about it there is usually somebody around who can give accurate answers . Hot water will make it stiffer on a temporary basis but if it isn't immobilized it will eventually become limber . I have done that on some holsters . I was told by an old timer to dip it in boiling water but have been afraid to try that . But he insisted it wouldn't hurt the leather . I tried drying a piece of scrap in the oven at 300 degrees and it burnt the leather and caused it crack . I only left it in about 5 minutes .I have sandwiched kydex between layers of leather to stiffen up notebooks I made and it worked much better than the traditionally used cardboard .

When I first started I put a mag carrier in boiling water. It is petrified. I have it hanging on my bench as reminder not to do that again.lol That being said. If it needs to stay hard as a rock and not ever flex again it will work. I also basically soaked it in Neetsfoot oil and it never softened.

[bikermutt07]

I think the boiling water water trick is for filled items. I saw a thread about midival water containers. They were filling them with beads or something to retain the shape before boiling. After they were emptying them and dipping in hot beeswax. I think?

 

Edited January 14, 2018 by bikermutt07

[DJole]

I have been playing with boiled leather for a few months now, after spending lots of time researching and reviewing instructions and videos from the internet. Marc Carlson's link (listed above) is a very good starting place. 
Here is what I have found:

(1) Boiling water (100 C/ 212 F) is NOT what you want. It cooks the leather too hot and too fast, and you'll have all kinds of warping and shrinking and brittleness problems. There is a big difference between shaping wet leather and shaping "boiled" leather -- you really only need to "boil" it if you absolutely want or need a large degree of hardness or rigidness (like armor, for example). Most pouches or sheathes don't need that much hardness or rigidity, so merely soaking in warm or cold water and then shaping them is fine. So whenever I mention "boiling" here, I don't actually mean "boiling," but rather nearly boiling, at the temperature that is best.  (Carlson discusses wax vs. water as what cuir boulli is, so I refer the reader to him on that discussion.)
(2) So what is the best temperature? It depends on two factors: the hide itself and the thickness. You will need to use test bits from the hide to find the best results.  If you don't, you'll waste a nice big piece of leather.  I have one piece of shoulder leather here which I have discovered reaches my desired results at 170 F, for about 20 seconds. The thicker belly pieces I have been using need 180 degrees, for about the same length of time, to reach the hardness I want. I use a BBQ fork that has a temperature gauge to check the water temperature.
This is difficult, because you won't KNOW if the temperature and time is right,  until after the leather is dry, which can take hours.  190 and above turns the leather into brittle cardboard. 
(3) It takes some practice to observe the leather in the water,  watching it bubble and curl, and know when to take it out. I have read some say to soak the leather for 10 minutes or so before putting it into the pan of hot water, and others say you don't need to do this. I'm not entirely sure yet which directions yield the most consistent results.
(4) Any tooling done prior to boiling is not going to look good -- cut lines swell and get hard edges; shapes warp and twist. The simpler the tooling or design, the less likely it is going to be mangled by boiling. I suspect that most historical boiled leather goods with patterns were embossed, rather than tooled. Tooling after boiling may work, but it would be difficult for 3 dimensional shapes, unless you have a rigid form or mould for them. And this leads us to...
(5) using some kind of rigid form to tightly hold the leather in a shape as it dries is great for boxes, pouches, and even knifes or shears. I did this for my leather shears -- wrapped them in plastic, then shaped the wet leather around them. Many people do this for knives, gun magazines, and so on. . 
(6) dyeing prior to water hardening is going to work better, unless you are using a water-soluble dye (like the Eco-flo dyes). Afterwards, you'll need to decide how to treat the leather-- it's only rigid, not waterproof. Water will spot and stain it. 
(7) it is also possible to soak the project and then dry it carefully in the oven, at a low heat. You need to test it (what heat? how long?), and WATCH it. I've only done this once,  so I know it works, but I don't know yet how to get beautiful, smooth, non-warped pieces using this process yet. (Again, I bet that keeping the leather around a form as this is done is the way to go. )