On Leather Hardening... [using Boiling Water/Heat-gun/Oven]

Ever wondered about different ways to harden leather? Well, I have, so I decided to try a few different ways, do you want to learn what I did? Watch this video to find out
Caution, if you don't like math/science, I am sorry, you may have to skip bits ;)
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Credit:
Lamellar armor [image] en.wikipedia.org/wiki/Lamella...
Latent heat formula [image] angelica11a.wordpress.com/phy...
thermal conductivity coefficient [Data] www.sciencedirect.com/topics/...
stuff is used under fair use, no infringement is intended
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Links:
Living Anachronism video on making Witcher armor: • Witcher Leather Armor ...
Living Anachronism video on making Witcher armor “Did I ruin it?”: • Leather Armor Hardenin...
Gloves I used for experiment 4: www.screwfix.com/p/uci-aquate...
[Links are for information, I make no money from them]
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Chapters:
0:00 Introduction
1:46 Ex 1: Boil hardening sample
5:01 Ex 2: Heat-gun hardening sample
15:30 Ex 3: Oven hardening sample
22:04 Ex 4: Boil hardening full piece
30:37 Conclusion
37:42 Bloopers
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Music:
Tavern Brawl by Alexander Nakarada ft. Kevin MacLeod | www.serpentsoundstudios.com
incompetech.com
Music promoted by www.free-stock-music.com
Attribution 4.0 International (CC BY 4.0)
creativecommons.org/licenses/...
Fluffing a Duck by Kevin MacLeod is licensed under a Creative Commons Attribution 4.0 license. creativecommons.org/licenses/...
Source: incompetech.com/music/royalty-...
Artist: incompetech.com/
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#fantasy #dwarf #leather #leather-work #hardening #craft #experiment #science #armor

[@jonanderson3050]

I love this long format style where you really dig into your process and the choices you make. More please! Also; "I can't recommend these gloves but I absolutely recommend these gloves." Love it!

[@IodoDwarvenRanger]

Glad you like the video :)

[@paulhelberg5269]

I so appreciate your diligence and adherence to the scientific method. I have also experimented with hardening leather and experienced mixed results. Too hard, and the leather becomes brittle with time. I experimented with mink oil, lard and linseed oil to condition hardened leather and reduce brittleness with some success. I really enjoy your approach to DIY videos my friendly dwarven ranger.

[@IodoDwarvenRanger]

Thank you for your comment :) as for treating it to make it last etc... I don't really know yet, all my smaller hardened projects have lasted just fine treated with lots of coats of mink oil, or neatsfoot oil so I think that is the way to go, but I also think that with water hardening the sweet-spot is 90-95 degree C, the big piece feels a lot less brittle (while still being hard) and that's how hot the water was when I measured it after it had been poured into the wide tray

[@isdhound]

Excellent tests and commentary, thank you. Don't you apologize for doing the hard geeky tedious math work. We, English majors would be lost in that world!

[@IodoDwarvenRanger]

No worries!

[@HistoryOnTheLoose]

Your calculations are incontrovertible. The problem, though, arises when you introduce a variable to the experiment. Leather is a non-homogenous item. It varies depending on the location on the animal (even if mechanically altered to uniform thickness), it has a grain which will cause it to stretch disproportionately in different directions, etc. The magic you seek is not in the water or the heat, but in the leather itself. Boiling the fibers, removing the oils from the tanning process, "cooking" the fibers to completely alter their state forever - that is what is causing the hardening. Cuir bouilli, French for boiled leather, armor was used for centuries. Placing your boiled wet panels in press forms, negative and positive, until dry will result in the product you seek. GREAT video. Totally satisfied the geek within.

[@chshrkt]

My brother and I made hardened leather armor pieces years ago for his kids and we used a large kettle (~20L) and tongs to fish out the soggy leather. We had metal salad bowls (to approximate simple helms), and some tree branches for the vambraces and greaves to wet form them. We only had regular leather gloves and some pieces of wood to shape them, but overall they came out great and his 8 and 9 year old kids loved them. :)

[@IodoDwarvenRanger]

Thx for your comment, That is awesome!

[@TexasJack1886]

"now that I've done some experiments, and some maths, and some thinking, and some research, I don't understand it at all anymore- science does that" LOL loved that bit. I know exactly what you mean especially in the field of interest I work in 😂 In any case I certainly appreciate all the work, thermodynamics, and worst of all WAITING you had to go through to make this video a reality and for the sake of good science. This one must have been TEDIOUS to film. p.s. You are absolutely BRILLIANT :) every time i thought i was going to be able to contribute a clever fix or tip in the comments, all I had to do was keep watching another 5 seconds and see you'd already worked it out lol

[@IodoDwarvenRanger]

Thank you so much, and yep LOL it wasn't so bad to film, but it was tedious to edit, especially when my PC wouldn't render it, it was meant to be up on Friday but alas, I needed more RAM

[@TexasJack1886]

@@IodoDwarvenRanger I was going to force a joke about "RAMifications" but I've decided to try and be better than cheesey puns lol

[@IodoDwarvenRanger]

@@TexasJack1886 RAMifications LOL

[@MikaelKjell]

First of all, I think you're an amazing and interesting young person😀👍 I was searching for information on how to harden leather for a pretty simple project, but because of you I can see it will be very difficult. Thank you so much for this video😀🙏

[@middleway1885]

Cheers to your ability to keep at things and provide education and entertainment... woooh! I'm excited to see what else you create! To your health and sanity... (projects not going your way... it's OK, it's science! True science!)

[@IodoDwarvenRanger]

Thanks a lot :)

[@2OldGeeksTalking]

Interesting experiments on leather hardening. Have you ever considered making a video on fire hardened wooden spears? I have heard of a few different techniques but haven't ever tried it.

[@IodoDwarvenRanger]

Thank you for your comment :) cool, I'll add it to the ideas list

[@seawinde]

I love all the physics and equations you are putting in this video , best of luck , this is lovely

[@IodoDwarvenRanger]

Thanks a lot 😊

[@marcocavaco3150]

This is great. I am thinking of making a hardened pouch to attach to my belt, this game me not only inspiration for that, but I will proceed with a bigger insight on the matter. Thanks Iodo!

[@IodoDwarvenRanger]

thank you for your comment, for a pouch I would suggest using 50-60 degree C water because you will need it to have a little bit of flexibility

[@DimlitKight]

This was an awesome and enlightening experiment! Keep up the great work!

[@IodoDwarvenRanger]

Thanks, will do!

[@LuxisAlukard]

I doubt that I'll ever make anything from harden leather, but this video was such fun, I enjoyed it!

[@IodoDwarvenRanger]

Thank you :)

[@another3997]

Very good experiments. The consensus amongst experienced leather hardeners seems to be that boiling the leather causes it to become very hard, but also brittle, which isn't good for armour. You would have to do some impact testing to see which provides better protection from both blunt and sharp objects. Put the leather on something roughly as squidgy as a human abdomen, get your hammer out and hit it repeatedly, then stab it with a nice, sharp, pointy thing. 😉

[@IodoDwarvenRanger]

Thanks :) and I was thinking of doing exactly that some time

[@TwoHelmetsDC]

I use beeswax to harden leather: waterproofs it and hardens it in a way that the leather doesn't become brittle. Melt a large block of beeswax down (I get from a local apiary) and then submerge the finished piece in the melted wax. Very little shrink. It would be difficult to do something as large as body armor, but it works well for drinking tankards and vambraces.

[@IodoDwarvenRanger]

I have read about that method, I might give it a go sometime, thanks for the tip ;)

[@taylorsteiner9273]

Very cool video Iodo!

[@IodoDwarvenRanger]

Thank you very much!

[@neoaliphant]

Interesting scientific processes, good video

[@IodoDwarvenRanger]

Thank you!

[@parasocialdaddy]

33:43 In my experience leather shrinks, holds dyes, and stretches at different rates based on where the leather is cut from as it's a natural material. When making belts, harnesses, saddle seats I use as close to the spine of the animal as possible. The neck and belly will have stretch marks and generally be more spongy and flexible in it's tanned state. My assumption then is that these differences translate to hardening processes in different ways. (Uneven shrinkage, softer final product, etc.) Lovely video ☺️

[@IodoDwarvenRanger]

Thank you for your comment :) I did wonder but because I only usually get pre-cut rectangles or off-cuts from factories etc... I don't usually get a choice in this, or even get to find out what part of the hide I have so I didn't have a way to put that to the test, but it's very interesting to know so thank you tanning is definitely a part of it though, because out of the two sources I use for leather one of them consistently hardens easily and the other one needs a lot more heat. However all the different pieces shrink seemingly random different amounts, so I guess that must be because of where on the hide it comes from?

[@parasocialdaddy]

@@IodoDwarvenRanger yes. If you continue, purchasing a 'side' will get you 22-28 square feet, but you can opt for 'shoulder', 'back' or 'butt' for the firmest pieces for less pricey options. 'belly' is often very inexpensive, but more irregular.. think handbags. Researching leather cuts with some of the above quoted terms should get you down the rabbit hole if you're looking to do more!

[@IodoDwarvenRanger]

@@parasocialdaddy thanks for the information, I'll keep it in mind ;)

[@dlema3155]

You can also bake the leather on wood without it burning. I use bits of 2x4 lumber to prop up items in the shapes i need them. Also, it needs 24 hr rest after baking before it's set. Try to handle as little as possible in that time, but you can fix small shaping issues. Awesome video overall! Keep it up.

[@IodoDwarvenRanger]

thanks for the advice :)

[@AdamUnpronounceable]

Really loving how each video you do is better and better. Do you have a PO Box at all for a fan to send you some gear? I have some audio equipment from some experimentation in KZbin myself and I feel like it gathering dust is a waste and perhaps you'd have use for it.

[@IodoDwarvenRanger]

no PO box, sorry, I've thought about it but I don't have space for people to send me things, and your offer is kind but I also lack the technical ability to use something like that

[@globalmarauder8682]

I love your content!I think you will need some kind of water proofing.... especially if you're going to use it in a humid climate. I suggest to try the Same thing with rawhide, shaping it is easier while saturated with water (it doesn't need an oven to dry and it's way harder if you use the ticker parts).... might be less pleasant esthetically. Peace.

[@IodoDwarvenRanger]

Thanks for your comment, and for the sub :) yep, If I made this piece into armor I would dye it, then treat it with neatsfoot oil or wax, but I really only made it to see if boil-hardening a larger piece was possible, I didn't intend to actually make it into something, but I might, I don't know yet

[@afternoobtea914]

Very interesting video and I do like the math.

[@IodoDwarvenRanger]

LOL, Thanks :)

[@jonathanmurray2986]

Question then a comment. Q: Is your durometer for Shore A or Shore D? C: Heat in physics is not the same as temperature, it means the amount of energy being transfered, so in your equation that you marked through, the original definition was correct, but so was your correction.

[@lukedaniel7669]

I speculate that 'hardening' and 'shrinkage' are synonymous in this context? That is the more it shrinks the harder it is, as the leather fibres will get closer together therefore much less flexibility, and the natural variation in the individual fibres would explain the uneven shrinkage. I think boil hardening a large piece would be perfectly feasible in a workshop setting, you would need a former set up ready and a large cauldron. It's been used in wooden boatbuilding for donkey's years. I wonder whether 100 degrees is actually the optimum temperature or just that without any measuring equipment it is a temperature that water can be held at for an arbitrarily long time (if it's boiling at standard pressure it's at 100 degrees)?

[@IodoDwarvenRanger]

cool thoughts, thanks for your comment :) as for optimum temperature, I have used everything between 40 and 100 degrees C for hardening, the hotter the leather gets the harder the leather, but it is more brittle and shrinks more, so depending on how hard I want it I pick the temperature, I don't have any real way of measuring, it's sort of by guess work

[@paulkopacz5051]

Very interesting tests. I think the dry hot air hardening achieved a kind of "Case hardening" or surface hardening such as you would get in mild steel if you add carbon to the surface but the interior of the steel would stay pliable and soft. I wonder if you were to place your boiled leather between two flat slabs of stone and allowed to dry that way if it would not curl, sort of a form for the leather plate. Also, can you cut the leather easily after you harden it so that you can just cut the size you need from a larger piece?

[@IodoDwarvenRanger]

Thank you for you're comment :) yep, I was going to call it Case hardening in my video, then I thought that not many people would know what I meant and the ones who did might criticize the use of steel terminology for leather in response to your second point, probably not, because the curl happens in the water, it's almost like the edges actually swell (or maybe the top shrinks more than the rough side, I'm not sure), I don't think it could be pressed back flat but it didn't stop me wet-forming that big piece into the shape I wanted

[@DIRKMCGURDIGAN]

I've never had any luck water hardening leather. Every time I've used water the leather was hard, but way too brittle for what I needed it for. In my shop we wax harden everything, which doesn't cause shrinkage (unless you leave it in the wax for way too long) and it doesn't dry the leather out the waybwater hardening does, so you don't end up with the brittleness.

[@IodoDwarvenRanger]

a few years ago a friend of mine did some (very unscientific) cut tests on wax hardened leather with a sharp katana, and it seemed to slice more easily because the leather fibers were lubricated, I would test this but I don't have the equipment to wax harden leather so water hardened it is ;) I find that I have to use neatsfoot or mink oil to prevent it from becoming brittle

[@DIRKMCGURDIGAN]

@@IodoDwarvenRanger As long as you replace the natural oils that are boiled out of the leather it should keep from getting too brittle. For cutting, I suppose it depends on the wax used? Most of the armor we make is for defending against blunt swords, so it doesn't come up often. The waxed stuff I have done cutting against was considerably harder to cut.

[@IodoDwarvenRanger]

@@DIRKMCGURDIGAN interesting, thanks a lot, maybe I will see if I can try wax hardened leather

[@czerniana]

I know htis is an old video, but what would your suggestion be for the method if one were making tablet weaving cards. Do you still have these samples? One year later is one harder than the other? Did they gain or lose any flexibility? Would be interesting to know =)

[@FritsvanDoorn]

Very interesting. I was thinking how brittle the leather was now. I mean, does it break when it is hit by a hammer? And the other thing is that I think that my oven is not big enough to have my armor as I am a large Dutch guy. 🤣🤣🤣 but thumbs up 👍👍👍

[@IodoDwarvenRanger]

Thank you for your comment :) "does it break when it is hit by a hammer?" - that I don't know yet, maybe I will do some tests, as with anything the harder it is the more brittle it seems to become, if you wanted to make sure it couldn't break you could harden it in 80 degree C water, it wouldn't be brittle but it would be hard enough to absorb some impact (purely theoretical) yep, that is why I think Lameller armor is not only more historically accurate, but more practical to make, I don't think I would fit a whole torso armor my size in my oven, Kramer did it but his oven looks to be a good 6'' taller inside than mine

[@MrJonboy002]

​@@IodoDwarvenRanger Agreed, I also remember the harder it is = more brittle. I overcooked a test piece and it cracked when I drilled it. I believe that you would use both (or more, like waxed) methods, depending on the context. With your Lamellar example, one could do a super hard chest section to take a hit (which would most likely crack/break) and replace them later (if your still alive). Then you might have the bottom row, toward the hips, be more flexible, for movement. There's also a place for non-hardening, or even doing areas of a single piece that may transition to different hardness'. "Right tool/process/material for the job". Awesome job figuring out the science and math!

[@IodoDwarvenRanger]

@@MrJonboy002 Hardening different pieces to different amounts is a cool idea that makes a lot of sense, interesting

[@DanOReilly46]

I’ve tried baking with many different temps and times and I can’t get any real results.

[@IodoDwarvenRanger]

in my experience just dunking it in hot water works, however it will shrink, Kramer over on Living Anachronism managed to perfect the baking technique tho, and he got better results than me

[@chiefkikyerass7188]

Why not just use a steam machine?..