Bark Tanning: Preparing the Hide

Bark Tanning: page 3

Fleshing & De-hairing

Please Note: These instructions assume that you understand basic tanning processes. If you don't, you should get one of the Recommended Books, or take a class.

Contents
Intro & History
Tannins & Tannin Sources
Hide Preparation
Making the Bark Solution
Soaking
Currying
Softening & Finishing

As in any type of tanning, it is preferable to use hides that have been stored frozen or wet-salted, or are fresh. Dried out hides are harder to re-hydrate and get good penetration by the buck and the bark liquor. For more, see the Storing Hides Tutorial.
Fleshing: Flesh as you would for brain tanning. Be careful not to damage the grain. You do not need to get every last bit of membrane off at first. Some people find it easier to membrane the hide after it has been soaked in the tannin for a few days.
Bucking/Liming: After fleshing, soak the skin in an alkaline solution of hydrated lime, wood-ash lye or commercial lye (see the book Deerskins into Buckskins for thorough directions) until the hair slips super easily. Limed hides, especially if they are limed for extended period of times, tend to come out somewhat less stretchy than bucked hides. This phenomenon has historically been exploited to create firmer leathers. If you don't want a firmer leather, you are better off bucking. See more below under 'Rinsing'.
Bucking or liming takes longer than it does to simply prepare a hide for brain tanning. Early on, the hair will pull out of the hide fairly easily, but you want it to be so easy that you can just push the hair out rubbing your hand over the hide. Deer hair slips more easily than many other types of hides.
You do not have to do this step though it is a classic part of the bark tanning process. The alternative, which some native people's do, is to let the hide "sweat" by letting it decay enough that the hair slips, but that the grain and hide are not marred. If you don't soak the hides in one of these alkaline solutions, it will take longer for the tannins to penetrate the hide and you will need to use more of them. This is because the alkali clean out a mucus that controls the movement of molecules through the hide.
De-hairing: To remove the hair it is best to use a wooden bar with a dull edge, or something similar. It should be more rounded than what you would use to scrape a brain tan, as you do not want to cut or mar the grain. You do want to remove the epidermis though, which is the dark pigmented layer just below the hair. Sometimes it'll just brush off with the hair, other times you'll need to make a conscious effort to remove it. The epidermis contains the pigment and is a darkish gray/black, especially in the summer. If patches of hair will not slip easily, return the hide to the alkaline solution.
Rinsing: When all of the hair and epidermis has been removed, rinse the alkali out of the hide by soaking it in running water for 12 to 72 hours (until all signs of swollen-ness are gone). Lime will leave some calcium in the hide, that to fully remove involves further processes that I prefer to gloss over here. These processes were employed when a limed hide was intended to come out more pliable and historically involved soaking the hide in fermenting materials such as hen or dog dung (known as bating), beer dregs, or fermenting grains (known as drenching). In brain tanning, one does notice that limed hides tend to come out less stretchy than bucked hides, particularly if the hide soaked in the lime for an extended period of time (more than three weeks) See Ancient Skins, Parchments and Leathers, for more on bating and drenching.