Posts filed under leatherworking

Ground Shots Podcast Interview on Bark Tanning With Kelly Moody

I sat down with Kelly Moody and traveling podcaster to discuss bark tanning. Kelly is a tanner herself and we get into specifics about tanning with tannic acid and some related stuff. It was fun and maybe we’ll do the same with some other topics when she comes back through sometime. This was my first podcast guest spot.

https://www.ofsedgeandsalt.com/ground-shots-podcast

The Worst, Common Bark Tanning Mistake

On the road from raw skin to leather, there are many potential mishaps. Skins and plant liquors are potential food for bacteria, yeasts and fungus and growing the wrong ones, or too many, or for too long, can damage or blemish a hide. When dealing with natural materials, we typically have a sizeable degree of variability to contend with. It is very likely that home tanners are dealing with materials and quantities they aren’t familiar with.

One cluster of mistakes that all lead to similar results or scenarios stands out as the worst common error. Put most simply it is, that the hide is left for too long, in solutions that are too weak. This can come about in various ways and have differing effects, but it is super common. In this video, I lay out the typical scenarios and try to offer an approach to prevent them. This is an important video for anyone starting out in bark tanning, because this general area of understanding is so often lacking in the beginning. Nearly everyone seems to make these same mistakes, I know I did, and they need to be headed off intentionally.

Because there are so many variables in natural tanning, it is impossible to accurately quantify all of this. I can’t give out step by step instructions with times and quantities. It just doesn’t work very well that way with all the variables involved, not the least of which is tannin content by species, individual trees and condition of materials. What I can give is a general approach to this problem that will allow you to adapt to new materials and unknowns. That essentially involves observation and understanding the typical way things go as far as the hide tanning rapidly at first, then requiring a high enough level of tannin in the liquor to preserve the skin as it finishes tanning. Also, that some color in the liquor is not necessarily indicative that is has any tanning power left. There is a measuring device called a barkometer, but I don’t own one and find that I can judge when to add tannin by observing the liquor and behavior of the skin. Bullet points are…

*Always look at the liquor, before, after and during, just always; any time you add liquor or check the skin, or have a new batch of liquor. Pick it up in your hand and look at the color and density. All materials are different in color and how much tannin v.s. other coloring matter they contain, so you are making comparisons mostly with fresh, v.s. used and partially used samples of whatever you happen to be working with.

This fresh, strong bark liquor has a bright look and high color density

This fresh, strong bark liquor has a bright look and high color density

This solution, while retaining some color, has no tanning power left, or not enough to matter.  It will grow bacterial scum on top and the hide will decay slowly, because it is just starting to tan.  All color is not indicative of effective tannin.  With a wll prepared skin in new starter solutions, this phenomenon can happen in one day.  Unless you add a lot of tannin quickly, (which is sometimes okay) it will keep happening, but eventually it will slow way down and the solution can be left for long periods of time unattended.

This solution, while retaining some color, has no tanning power left, or not enough to matter. It will grow bacterial scum on top and the hide will decay slowly, because it is just starting to tan. All color is not indicative of effective tannin. With a wll prepared skin in new starter solutions, this phenomenon can happen in one day. Unless you add a lot of tannin quickly, (which is sometimes okay) it will keep happening, but eventually it will slow way down and the solution can be left for long periods of time unattended.

*Understand that in the beginning, hides typically take up tannin very fast.

*If the skin is left for any length of time, the liquor needs to have enough excess tannin to adequately preserve it, and also to insure that tanning continues to progress.

*Be prepared to gather/prepare/add more tanning material as needed. Thoughts such as you used a “lot” or it “should” be enough are not really relevant. It’s either doing the job, or you need more. Sometimes that is a lot if the materials are not very rich in tannin, or it is something that is just hard to gather in enough mass.

*A healthy tan can smell quite strong and in a way unpleasant. I would characterize it as unpleasant, but kind of intriguing and not just flat out disgusting or vile. It is an odd smell that will cling to your skin for a time after touching it. While an element is unpleasant, there should also be a large measure of fermentation to the smell. All of that is normal. It shouldn’t just smell putrid or flat out offensive in the way that rotten food, a dead animal or an outhouse does. Some growth of stuff on the surface can be normal.

*Typically, tanning will progress very rapidly at first, then slow down a lot as the core of the hide slowly tans. Keep the solution rising in strength if anything during this initial phase, then leave it strong enough to maintain a healthy tan as it finishes. Common ways to fail at this objective are: Using low tannin materials, not using enough material, putting the hide in and leaving it without strengthening the tan, Judging by how much it seems like you’ve used instead of by how tanning is progressing (or not), and what the liquor is doing.

*A fairly reliable approach is to cook the material twice. Use the second cook liquor to start the hide, with some water add as necessary to cover the skin well. observe the liquor before putting the hide in. Add the stronger first cook liquor over the several days as you see the liquor depleting and the hide tanning. If you run out and it still seems to be drawing down the liquor, make more. I also talk in the video about dumping some of the liquor to bring the water level down and the tannin level up to get a solution you can leave the skin in. When it is no longer rapidly depleting, you can get the strength up and attend it less frequently. This approach gets most of the tannin out of the material, prevents any possibility of tanning the skin too rapidly in the beginning, is continually adaptable, and encourages familiarity with our materials and their tanning potential.

That is the quicky version, but it should be enough to avoid this worst common problem in bark tanning.

I’ll link two video playlists here. One is a lot of useful general tanning videos and the other is my strops from scratch series, which follows the tanning of a deer skin with oak bark.

Bark Tannned Leather Clinic With Zack, Vegetable Tanning

graomomg booaoe.jpg

Zack Hribar came over to show me his first batch of bark tanned leather.  We shot an informal video talking about them and vegetable tanning options, troubleshooting the hides, stories and that sort of thing.  It was fun.  Zack is an enthusiastic new bark tanner, check him out on instagram as z._hriack_bar

Finishing the Oak Bark Tanned Deer Leather

Cute  and  practical, just how I like 'em!

Cute and practical, just how I like 'em!

Last winter I started a project oak bark tanning a deer skin to make leather for the axe strop project.  The project follows the collecting and processing of materials to build pocket sized sharpening strops as prizes for people who completed the Axe Cordwood Challenge.  I'm making everything I need for the strops and decided to show the whole tanning process and everything else in a series of videos.  Almost 6 months ago, I laid the prepared skin away to tan in oak bark.  It sat in there about 4 months longer than it needed to, but I took it out and finished it this week, and it looks like it turned out pretty decent.

The leather is perhaps a little light and spongy, "Empty", as they say in the tanning trade.  Emptiness results from the loss of structural proteins in the skin by chemical or bacterial action.  It isn't much of a surprise considering that I over-limed it to start with, and that it sat in a weak vegetable tanning (plant based) solution for 4 months longer than it needed to.  Those are actually the type of things that a tanner might do on purpose to a hide in order to make the finished leather soft and pliable.  That's not what I was planning though.  I would prefer a rather firm and weighty leather for this project, but that is not even the nature of deer to start with.  Deer skin, at least our deer skin here in the Western U.S. has an open, coarse-fibered, low density character that lends itself well to softened leathers.  It would have been better to move it through the process faster with shorter liming time.  But, a process that uses somewhat preservative solutions like lime and tannin, begs for procrastination.  Add that I have to make videos of it all and it's a perfect storm for not getting things done in a timely manner.  It will probably work fine for the project, but I haven't assessed it closely yet.  If it doesn't work out, I have plenty of other skins I've tanned over the years that are suitable and I got to show the process start to finish, with some of the warts and mistakes that any home tanner is likely to experience.

The next steps will be making the wooden paddles, making glue and putting it all together into the finished product.  I only need a small amount of leather for the project.  Seven brave and industrious individuals chopped one cord or more of firewood for the cordwood challenge using axes only and will receive a finished strop and a leather patch when they are made.  The balance of the leather will be stowed away with the rest of my leather cache, to wait for a suitable project.

Original Illustrations From My Book, Buckskin, The Ancient Art of Braintanning

In the 90's I wrote a book with the my partner at Paleotechnics and Wife at the time, Tamara Wilder.  We need to reprint and were sorting through the original copies so I made a quick video showing some of them.  We have a few copies of the book available on http://www.paleotechnics.com but I took it off of Amazon until we reprint, though some sellers may still have a few strays for a while and there will be the inevitable copies selling for hundreds of dollars claiming that it's out of print.  Which, I guess it almost is now.  Hopefully we'll have it back in print soon.

Axe Strops #5, Rinsing, Drenching and Bark Preparation

In this segment we repeatedly rinse and scrape the skin to remove lime and unwanted gunk, then soak the skin in an acid drench made from fermented bran and water.  Oak bark is prepared by chopping and cooked to make the tanning solution.

Pocket Axe Strop Production Part 1, Introduction, Liming Hides and Selecting Wood

This is part 1 of my project to build up Pocket axe strops from scratch as incentive/rewards for the Axe Cordwood Challenge.  I may also sell some on the website depending on numerous factors.  For those who don't know, a strop is a device for polishing or refining a sharpened edge.  it is the last step in many sharpening sequences and can also be used to touch up edges, especially if polishing compound is used.  It usually involves leather, which my design of course does, but the act of stropping can also be done on wood or even cloth.  In this project, I'm building strops from the ground up, which involves, tanning, glue making and working up some wood from it's raw log-like state.  There should be no materials used in these strops that were not processed by me here on the homestead, down to the lime and fat used in preparing the leather.  The project will span an undetermined number of videos, as well as a short version of making an easy high quality hide glue from scraps that most hunters or butchers of animals typically throw away.  Almost anyone who is not me should learn a lot from this series and I hope to learn some stuff too! ;)  Feel free to vote on names for the pocket strop or think of new ones... Stropet, Pocket Strop-It, Pixie Paddle (the woods are a dangerous place full of mischievious pixies!).