Bark Tanning Hides
If you happen to pick up "The Book of Buckskinning 7 on page 222 there is a most excellent article by Mark Odle on the process. If you can get your hands on a copy it is worth it to understand what is happening in each step. First off my comments: Brain tan is not leather it ...is ruffed up greased skin. A lot of folks think it is the leather of the 18th Century , well they are wrong. Bark tan is real leather . Now brain tan takes intensive work over a period of a few days. I can say Bark tan is probably as intensive but the work is spread out for months so I say it is a lot easier.
( In a nutshell version) If your like me the easiest to obtain hide is deer.
The hide is removed from the animal carefully and laid out on a fleshing beam or a log. The flesh side is scraped with a dull knife to remove any traces of flesh, blood and fat. ( this is a lot of work) I sometimes spread this out over a few days going at it for about an hour at a time. If it is cold just roll the hide up and it will keep a good while. If it is going to be longer then sprinkle the hide with canning salt ( 100 % pure sodium chloride) to help it stay fresh. Sometimes I will do a quick job of scraping in the winter and preserve with salt until the weather gets warmer and more comfortable.
Once the hide has been thoroughly scraped, wash it off. it will now be very soft. Then get a large plastic tub or garbage can. Put in about 15 gallons of water and about a 4 lb bag of hydrated lime (Garden Centers have this). Stir well and place the hide in the liquid and turn often for about two or three days just until the hair starts slipping off the hide. At this point bring it back out to the fleshing beam and very carefully start scraping the hair side. Be careful not to cut the hide because now there is not the cushion of hair between the hide and the beam. It may not all come off easily so throw it back in the lime water for another day.
Then try again. After all the hair is removed carefully scrape both sides of the hide to remove any lime deposits.
Rinse hide in a plastic tub for about 6 to 8 changes of water. Your hide now will be swollen and very rubbery and somewhat firm
Now for the bating process (you love this)
get yourself about 5 gallon pail of chicken manure (fresh cow manure will work also).
Mix with enough water to make a medium slurry and immerse the hide in it turning constantly for about 20 minutes then let it sit for a few days turning every so often. You will know when it is done when the hide goes back to the original soft feel.
Now alternates I have used are - a very scummy top of a pool cover were dozens of birds used to bathe and drink & defecate in the period from when the weather was warm enough for no ice and of course before swimming season. Now this worked great (took 5 days) but didn't go over well with the family especially when the neighbors called and said somebody had drowned & was floating on top of the pool!
Also you can buy at the grocery store 1/2 gallon of buttermilk and a box of pure bran. Mix the two and put the hide in this along with about 5 gallons of water and mix often for about 5 days (personally this smells worse than the manure)!. So after the hide is bated and soft, rinse very well at least a dozen changes of water and again carefully scrape the both sides of the hide until it is clean & smooth
After the bating process the hide is now soft again and very clean and light colored no traces of any connecting tissues on it anywhere.
While you were doing all those previous steps you should also be doing another before this stage. Making the bark liquor. If you are very lucky to obtain a bushel or two of fresh "white oak" bark you are set. For me this is tough to get but I like it the best because it produces a nice brown leather. Up here in North East PA, the tree of choice has always been hemlock (produces a russet colored leather) In any case get as much as you can get (Fresh- not the garden center variety). Saw mills are good to check in the late winter. The fresher the bark the better. Now the fresh bark can dry in a container but what you don't want is the stuff that has been laying around getting wet and loosing potency. I put my bark through a shredder although years ago before said machine, I cut it all up in tiny pieces by hand! I get a large porcelain canning pot and pack it with bark and fill with water and bring to a boil (I have done this in the house when the wife is away- may be better to do outside). Boil for about an hour let sit for a few hours, drain off liquor in a clean plastic container. Fill up with water again, boil again, cool and drain of into another plastic container. I will do this three times with each batch of bark. for each pot of bark you produce a first concentrated batch of liquor, a second weaker batch and a third weakest batch. Dump out the bark (you can use it for mulch now) Fill the pot up with fresh bark and repeat boiling for three more batches. What you are looking for is at least 5 to 10 gallons each of three concentrations of bark liquor for one deer hide. I store each batch in a 5 gallon cleaned spackle buckets with lids put on to keep them clean. You most concentrated batchs should somwhat sirupy.
Ok now to go back. The bated hide after thorough rinsing and final scraping is place into the weakest bath of cool bark liquor. Stir constantly for about ten minutes. You need to have a plastic tub big enough so the hide is somewhat loose. Don't cram it into a 5 gallon pail. Plastic garbage cans or rubbermaid tubs work well. ( Keep in mind to be period correct with this you would need wooden tubs or vats). In this solution the hide resides with as much turning as possible (every few hours for the first few days. Then a few times a day for the next 4 to 6 weeks). The vat should retain a nice "earthy" smell never like sulfur. If that starts to happen add some white vinegar 1 qt to 5 gallons bark solution.
You can see where this is going. 4 to 6 weeks in the weakest concentration then 6 weeks in the next stronger then finally after about 10 to 12 weeks into the strongest bath. By this time you can be down to one good mixing and turning a day. Warm weather is your friend here. If you had good bark and did your prep well there is good leather in 6 months although you can leave in longer. I have gone up to a year. During this time it is always a good idea to have made up an even stronger batch of liquor by boiling pots of fresh bark draining the concentrated liquor and use this as the liquid to boil a fresh batch. This way you have a super concentrated batch which I add to the final vat the hide is in from time to time to keep it strong.
When it is leather, it is taken out of the vat and rinsed may times (12 or more changes) in clean water. Then the hide is place on a firm hard surface and use a piece of smooth hard wood to squeegee out eexcess water. But do not let the hide dry. Make up a batch of 100% pure neat's foot oil & a small piece of beeswax and heat up until the wax goes into solution (be careful it is flammable) when cool enough to touch, rub this into the hair side of the hide as thoroughly as possible. You can even use the piece of wood to press it in and expel the excess water. This is called currying the hide. When you are certain you have it well oiled flip it over and let the flesh side face up and let the hide slowly start to dry.... do not rush. You want this to take place over about two days. During this time every once in awhile pick it up and work the leather by pulling & stretching. I mount a piece of maple wood in a vice. So that it protrudes,( I have the edges rounded over somewhat) I will pull & stretch the leather (flesh side toward the wood) to break it in and make it soft. Keep doing this a few times until dry. At this point dampen it down again with a with cloth or spray bottle. Warm your oil up again and rub the flesh side with the oil to give it an overall light coat. twist pull and strech it all the while. If you do this for awhile the leather will dry while you are working it and it will stay pliable.
Now you have 18th c leather!