Caffeine: the most potent artificial intelligence drink!

Caffeine: the most potent artificial intelligence drink!
Deep in the Lair of the Perpetually Curious Fox

Saturday, 21 January 2012

Experimenting with Alum Tawing ... white tail deer hair on neck skin

Decided to give Alum Tawing a try to see how well the hair sets in. Alum (Potassium Aluminium Sulphate) is a naturally occuring salt, that has been used for food (and leather) processing, with good solubility in water and sweet-acidish taste. It also one of the more popular tanning chemical that is relatively harmless (to humans and the environment) compared to the more commercial chemical formulas on sale. Not to mention, cheap!

I loosely followed the instructions as outlined by this document by New Mexico State University on Tanning Deer Hides and small animal furs.

First, as always, get your skin/hide/fur. In this case I'm using a piece of white tail deer's neck skin, that's been preserved in the freezer without being salted first. I gotta mention that I am not too fussed if the hair comes out, as the deer was delayed in being skinned, so some degree of bacterial action on the hair follicles has happened prior to the freeze. So, without further ado, I popped it in a bucket of warm soapy water to thaw, and clean off blood, rutty smells, and excess fats. Don't soak it for too long, deer hair on skins are notorious for slipping if immersed in (especially alkaline, like soap, borax, etc) solutions. That's why "bucking" in Ca(OH)2 solution is so popular with tanners who wants the hair off without the epic scraping.

Once washed and rinsed, the skins were rolled up in a towel to dry off the excess moisture, and dry off the hair as much as possible. Once the hair side is dry (use a hair dryer if you've got one, or put it near a heater vent - don't cook the skin!) tack them onto a flat board.

There's two pieces here, one will be used for the Alum Tawing experiment, the other will be used for Tea Leaves tanning experiment (another post!).

Once nearly dry, you should be able to scrape the membrane off very easily. In my case, it's just a matter of working an "edge" of the membrane off the skin, then just pulling them off. The more stubborn bits are subjected to a sharp knife, pumice stone, or sandpaper.

See, it comes off in sheets!

Membrane bits. You can save it to make hide glue for other projects. I tend not to both for this amount, as I have a stash of dried sinewy bits for my glue source.

You know you've scraped the membrane off when the knife scrapes clean. What's left is the tight rawhidey skin.
You DON'T have to tack it to dry to scrape the membrane off. You can wet scrape it straight after washing. I just find it's more convenient to scrape it when it's dry, as well as practice run before I attempt dry scraping a whole framed deer hide for an upcoming braintanning experiment.

Once it's de-membraned, pop it in a plastic container filled with water with some alum and ordinary salt diluted in it. For a small project like this, I think 5 days is enough. If it were a whole deer hide, I'd probably leave it in the pickle solution for 7 - 10 days. Don't forget to check it daily and stir often (twice a day is plenty for a piece this small).

The reason why you should check it everyday, is so you can witness the process in which the hide turns literally white all the way through. Cut a snip through at the edge to check. Don't forget to stir! It should also NOT smell of anything!

Once the skin is struck all white throughout the whole thickness, take it out of the pickle, and rinse.

See, it's white all the way through. It also has plumped up significantly, due to the alum molecule forming crosslinkages throughout the collagen fibre network (which is the basis of tanning). However, this alum-collagen linkages are not waterproof, so if you wash it too much, the "alum tanning" is undone.
 White it's still wet from the wash, rub in the dressing.

While waiting for the oils emulsion to soak into the fibres, flip it over, and dry off the hair side thoroughly. The skin will hold plenty of moisture so you don't have to worry about it drying stiff before the hair is dry.
A plastic fork works good for fluffing it while it dries.
So far no hair slippage ....
When the hair side is dry, work it a bit to open up the fibres. Back of a chair, spoon, hand softening, whatever. This is where I notice that the project piece is shedding a whole bunch of hair. It didn't quite go bald, but the shedding is annoying. I guess I should NOT delay skinning a deer next time. The buck was hanging in the garage (it was a little bit around freezing temperature) for a couple of days before it was skinned. Bad mistake, if you want a hair on hide! (Kicks myself)

Then, hang it/pin it and let it dry a bit more, until the point where it's no longer "wet" to the touch, but still "cool" to the fingers (meaning it surface is dry, but the inner fibres still holding some moisture).
I clipped it with a folder clip, and  hung it in a warm area.

 You know when to start re-working it when you see patches of "opaque white" on the surface. 

Then give it all you got, work it with your hands, staker tool (spoon, blunt knife, deer bone), back of the chair, etc, until it is completely dry. When you think it's dry, work for another hour. And yes, it shed like crazy! Maybe for the rest of the hide (still in the freezer) I will have to remove the hair. I intend to leave to grain on, though.

So there, that's what the alum tanned hair on deer neck skin looks like. Would I do it again? Yes, but probably won't use it for making things that will see moisture. Maybe I would experiment with rubbing beeswax to make sure the surface, at least, repels water. For a beginner learning a hands on technique of tanning, I'd highly recommend it, especially if you're after a pure white leather look.

It does take a bit more work to soften, compared to the oil/soap tanned method.
Here it is compared to the tea tanned neck skin (still not struck through, will post when it's done)


  1. Excellent tutorial. Thank you for taking time to do this. Not allot of step by step out there for alum tanning and you have done a great job. I have done a beaver, one deer and working on my first fox. Your tutorial was very helpful and so far all have turned out. Hope the fox goes well. Thank.

  2. So glad this helped you out, James. Can you link to me some photos of your projects? I haven't done anything apart from deer hides (because that's one thing I have plenty off, and not scared of messing up royally).

    Will try on squirrel/coyote if I ever get my hands on them.

  3. hi! im sorry im a noob for asking this bit Really wanna try this method) if i go hunting for small game (first time) after i skinned my fresh catch can i use salt for preserving it? maybe two or three days before i can get back home to do any tanning

    1. Hey PRC5o

      Sure, make sure you flesh it well and have plenty of salt. It should dry out great. You can dry it without salt, too, but I prefer with salt if there's lots of moisture.

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