Hey darling what are we going to have for lunch? It smells funny in here. Oh not much, I’m just cooking some leather…
As you may know we are using warm and cold water in the treatment of leather. But did you know that we are cooking it as well? For instance shoemakers are placing patent leather in boiling water to get it around a heel.
What actually happens when cooking leather? The leather will soak up more water than it does with cold water. The leather goes a little thicker. It also shrinks a bit. The hot water does in seconds what time will do as well, but just very fast. So leather literally dies and gets as hard as a “rock”. Well not really, but it gets really hard.
I found an article of a guy making armor. Read it here.
Obviously this isn’t what I’m making. The leather I have been using for my test is veg tanned 2 to 3 oz. leather. Actually I started this test by mistake and with boiling water. That would be 100°C. If you are a Fahrenheit child, refer to this chart please.
The leather I put in boiling water has become noodles in a hurry. It shrunk and curled up faster than I could notice. The after all result was a leather that one could use to drive in a nail. It has become extremely hard and increased thickness by 50%.
This got me curious and I thought I should play around a bit with it to see what I can do with this. The result was a test series of 2 to 3 oz. leathers, placed in water for a very short time at various degrees. It was more of a short dip than actual soaking. The heat penetrates the leather faster than you might want to. The hotter it gets the faster it goes.
From what I knew of my boiling water experience I started at 75°C and went down to 60°C. I stopped at 60°C because the standard tab water is at around 45° to 55°C and for hospitals and such at 60°C. Since I’m usually using tab water for all my tooling projects I knew what to expect below these 60°C. So there was no point to go any lower. I stopped at 92°C. This is when the leather went to become noodles again. One other thing you’ll notice it that the hotter it gets the darker the leather turns.
As you can see I took pictures of the exact temperature when I dipped the leather into the water. Please note that I never waited until all bubbles disappeared.
About 2 to 3 hours later, some of the pieces have been dry others weren’t.
To save you some reading and me some writing I made this short video. And you’ll see pretty much what happens with the leathers.
After all of this testing I had to put it into practice and made a phone case for my daughter’s smartphone.
I dipped the leather into 85°C hot water for the blink of an eye. As you can see, it is holding its shape quite well and no discoloring is noticeable.
Do you have any experience with heat and water treatment of leather? Please let me know. I’m very interested in your experience and what or how you use it for. Did this info help you? You’re very welcome.