For The Love of Bucking! (also, case hardening)
I went on quite an adventure this year into the putrid and the foul, and have come out with an entirely new appreciation for the bucking step in vegetable tanning hair-off hides.
(For the purpose of this article, the term “bucking” refers to the practice of soaking a hide in an alkaline solution such as wood ash and water, until the hide swells, then scraping off the hair and epidermis, and rinsing the hide in fresh water for 1-3 days afterwards to return it to neutral pH)
Wild Roots community and the tanning culture at large here in Western North Carolina introduced me to some particularly foul practices of hide tanning which I had, in other parts of the country and as a traveler, not yet encountered so up close. Things like stream rotting deer hides to slip the hair before vegetable tanning, rotting hides by hanging them in the shade to slip their hair before tanning, tanning hides in fairly weak solution such that they remain foul smelling the whole way through the process, and just all around having a lot of mysterious buckets of nightmarish liquids and solids clustered around the landscape.
I had certainly dealt with the putrid before, but not on the scale of deer hides, and after some particularly frustrating experiences last Winter of hides over-bucking in wood ash solutions, this Spring I pondered if letting hair slip by rot may be an easier, more natural way to go, which would reduce my need for wood ash or store bought lye (which I haven’t used since my first years of making buckskin and don’t even remember how). Also, my community’s very shoddy freezer failed, and one of my landmates asked me to help him sort through the mountain of now very foul deer hides and small furs he had stored in there. Of course I said yes!
As an aside, I never recommend storing large amounts of hides in freezers, as freezers inevitably fail, which always results in a nightmare. My deer hides, heavily salted and stored in a bin in the cool root cellar, suffered no problems or setbacks this year.
First I bought a pair of rubber gloves and extra isopropyl alcohol. I put one of my salted deer hides and one small hide from an immature buck we had recently picked up as roadkill into the stream to hair rot them. Wearing the rubber gloves, two of the enormous buck hides from the freezer, which smelled like sewage, I thawed and simply scraped the slickly slipping hair off right away. The skin of those hides seemed strong. They didn’t tear, and the grain looked good, so I had high hopes that they would tan nicely and make good leather. I was bound to the idea of saving that freezer full. I also pulled out a slightly foul possum from the freezer to further rot in a bucket of water because the hair was still quite stubborn.
I worked for several months on those deer hides. I fed them tannins constantly, using whatever I had--hemlock, wax myrtle, smooth sumac, winged sumac, black walnut husks--tending fire after fire, being tied to them like children, as is always the case for me. All four hides turned out, in the material sense, as failures.
As of a month ago, I’ve gone back to my old method of bucking hides in an alkaline solution, and am loving and appreciating it more than ever. Here’s why:
1. It is so difficult to get all the hair to slip from a hide evenly when stream rotting it. Often the thinner areas of the hide will slip hair first, while the neck and spine simply refuse to let go of hair at all, at least not before the grain on the edges of the hide is rotting. Sometimes the hair will slip from a hide in nonsensical patchy ways--a little here and a little there, which also makes it difficult to evenly scrape off the epidermis. In order to preserve the grain on the thinner areas of the hide, I and others resort to submerging the hide in weak tannin solution before the hair has slipped from the neck, in order to begin preserving (tanning) the grain on the thinner areas of the hide while still encouraging some bacterial decay in the thicker areas of the skin--essentially, rotting the hide a little bit while tanning it, and pulling off the remaining areas of hair as I go. I don’t find this to be an ideal way to tan.
2. Handling hides which have decayed enough for the majority of the hair to slip is a real health risk. I perpetually feel my immune system being over-taxed. I don’t like wearing rubber gloves all the time and having to buy new ones as the old ones quickly wear holes. I don’t like the tanning solutions to be bacteria filled. I’m a taster when it comes to tanning liquids. Tasting daily is how I keep an intimate understanding of the tanning progress of each hide, and how I know when and how much to strengthen the solutions. When tanning rotted hides, this is mostly guess work, and I tend to err on the side of letting hides sit in solution longer, until it is likely that nearly all of the tannins have been absorbed, before replacing it with fresh stronger solution, because I can’t bear to waste tannins. Also, with these rotted hides, I usually desire to dump the used tanning liquids altogether, rather than use them for boiling more plant material, because I’m wary of their possible bacterial activity. And pouring out solutions like that just really doesn’t feel right to me as a tanner. Once these hides are far enough along in tanning that they seem more sterile, I begin tasting the solutions again, but only after boiling a cup or so of it first. And even still, tasting these solutions seems to me to be an unnecessary hazard. Paranoia always exists in the back of my mind, despite the rigor of my cleanliness practices.
3. Hides which have not been bucked and rinsed prior to tanning really do behave very differently from hides which have been bucked. I was truly amazed at this. For one, the non-bucked (aka stream rotted) hides tanned much more slowly than bucked hides. The non-bucked hides also had a different texture and feel than bucked hides: the skin felt fuller and more mucousy than bucked hides. These non-bucked hides, throughout their weeks and months of tanning were therefore also very difficult to wring out. I had to hang them up and squeeze out liquid rather than simply twist out liquid like a cotton shirt. I attribute all of this to the hides being full of all of their naturally occurring mucous, which in the process of bucking and rinsing are normally stripped from around the protein fibers of the skin, leaving them naked and ready to bind with tannins.
4. It was a very different experience for me judging the completeness of non-bucked (stream rotted) hides in their tanning solution versus hides which had been bucked. Expecting it to behave like every other deer hide I had before vegetable tanned in the past (all of which had been bucked first), I totally misjudged the completeness of the first non-bucked hide I took out of solution to soften. The hide seemed done by all my observations, and had been in solution for over two months, which is longer than I typically ever need to tan hides which have been bucked first. After oiling and softening, this hide felt like half-tan. It was tough and stiff, very much like there was still raw hide in its center. It was certainly not supple leather, and I was heartbroken by this, given all the labor and care I had put into that hide.
5. Stream-rotting hides has not been, in my own experience, a faster, smoother, or less materials dependent way to tan than bucking hides. In fact, in my experience, taking these hides through the process of tanning took more time and more labor than tanning bucked hides, with much less consistent outcomes.
6. When hides rot the grain layer of the skin quickly begins to break down and become weak. Even if the grain looks good before you put the hide in tannin solution, you may find that patches continue to peel off or slough away during the hide’s early weeks in solution. From the two large freezer rotted hides, I ended up scraping off large areas of grain mid-way through tanning, because the grain was so patchy and/or loose. I rathered to have a consistent grain-off vegetable tanned leather than an incredibly patchy, some grain on some grain off hide.
7. It is a new theory of mine that non-bucked hides may be more susceptible to case hardening than bucked hides. I case hardened a hide! After years of tanning heaps of small fur hides, small hair-off leathers, and a fair number of vegetable tanned deer hides, I had come to the conclusion that case hardening was a myth in hides thinner than cow, because I never experienced any signs of this mysterious pitfall and have always kept my tanning solutions incredibly strong (even when tanning deer hides). Well, now I know it’s real. The small, immature car-hit deer hide I stream rotted prior to tanning case hardened within the first week, and I actually suspect the first few days of tanning. The outer fibers tanned and shriveled together dramatically, and the inner fibers remained mushy rawhide...for months afterwards, as the hide continued to sit in strong solution with no change or advancing of tanning. This theory is a loose one. The other important factor to this hide is that I tanned it with Sea Grape (Coccoloba uvifera) bark. Though I have experimented (successfully) with this bark in tanning some small hides before, this was my first attempt with a deer sized hide (I had been patiently waiting for a small deer hide in order to use the precious bags of this bark I had painstakingly harvested last year in South Florida after hurricanes took many trees down). Sea grape bark is incredibly tannic, and this solution may have been the most tannic solution I had ever yet made. Not by a long shot. But by a little. So, this hide may have case hardened because I finally reached just above the threshold of what tannic strength of solution is acceptable in tanning hides. But it is quite suspicious to me that the first and only time I’ve experienced case hardening is on a non-bucked (aka mucous filled) hide. I can easily imagine how the mucous barrier surrounding the skin’s protein fibers could have some effect on tannins not being able to pass freely into the deeper layers of fibers and somehow compound into a hard crust. The jury is still out on this new piece of learning.
8. Did I mention that these non-bucked hides tan slowly? Scudding hides (aka, removing them from solution frequently to scrape them, which squeegees out liquid) which never made any sense to me before makes a lot of sense to me now as a necessary part of tanning non-bucked hides. I suspect that scraping these hides from time to time may help to press out mucous from the hide as it slowly releases from the fibers and to encourage new tannins to be flushing through the hide. This is not a step that I would ideally like to do on a regular basis when tanning large hair-off hides. It seems to me to be an enormous extension of time and labor. Thus, those two enormous freezer rotted hides are still currently in solution. I think it’s been over three months, and honestly most of the time I try to forget they are still over there in their buckets. They don’t seem even close to being done, and frankly I’m tired of tending to them. When I cut cross sections of the skin at the neck, the inner fibers feel slimy and deteriorating, and very much untanned (but not case hardened!). I will probably keep throwing tannins at these hides from time to time, but if they do turn out as anything, I don’t expect them to be done in under a total of six months (keep in mind that I’m used to tanning deer hides within one month, or two at maximum).
To sum up, let me re-iterate some of the practical benefits of bucking hides in an alkaline solution:
Soaking in an alkaline solution keeps hides fairly sterile, or at least more-so than leaving them in a stream. These hides, even after rinsing, have less bacterial activity, and thus have less potential to be health hazards. Well bucked and rinsed hides, once submerged in strong tannin solution, are clean enough by my standards that I taste their tanning solutions daily without concern (as long as I keep the solutions strong).
Bucking & rinsing removes much of the mucous from a hide. A hide’s protein based fibers, once cleaned of mucous, accept and bind with tannins quickly and readily, which means that these hides tan faster, without the need for continuous scraping (aka scudding).
Free from mucous, bucked hides are easy to wring out, like a sponge or a cotton shirt. You can squeeze and twist out much of the liquid in these hides by hand, which encourages fresh tannins through the skin fibers and thus even faster tanning.
And lastly, bucking a hide causes the hair to slip from all parts of the hide fairly evenly and predictably. This makes it easy to remove all the hair and epidermis from a hide in one act of scraping, and leave a perfect or nearly perfect grain.
Bucking is not just about removing hair from a hide. It affects the tanning process on many levels (both vegetable tanning and brain tanning for that matter!), all of which are worth appreciating!
<3 <3 <3
~Victoria, August 2018, Sodom Laurel NC