The way its finished can produce different types of thin, drapey, thick or stiff leather depending on what you want. If the hide is showing only a white line and you've got even color on the surface you can pour strong first boil at high solution in there and tan the rest of the way through without worrying about case hardening. As the hide tans, absorption will slow, now you can rinse the hides and prepare solution with the stronger first boil. Keep agitating and removing depleted solution/adding tannin over several days. If it starts to look like weak tea, it needs more tannin. Color is not a great indicator, but the solution will lighten and get milky as the tannic acid absorbs into the hide. If you see bacterial film on the solution or yeast bloom in the vat, your solution is way too weak. You have to keep the tannins in fairly high solution, they will be absorbing quickly. ![]() Mechanical help is needed to allow access to every inch of hide, it will not soak in on its own and this is how you can wind up with light blotches. Put your hides in the second boil/water and agitate them, stretch them stir them. Take note of how the stronger tannin has an astringent quality and will pucker your mouth like biting an unripe persimmon and will be very saturated with color. Take the second boil and add 50 to 100% volume water, this will be your first solution. The first boil will be stronger, save it back. What I learned in an online course is that you can usually gather 2 boils of liquor off of a pot of bark. I've heard all sort of percentage values, but there is no real way to guage the strength. When you scud clean water out of the hides and they no longer leave the rinse water dirty, you're ready for tannins. This not only cleans the hide but stretches it and opens the grain to prepare it to both absorb and adsorb the tannin and let it bond to the keratin. Scudding is basically squeezing the undesirable liquid (lime, dirt, fat, membrane, hair roots) out of the hide with a dull blade. Once bucked and all hair is slipped, you should rinse thoroughly for several days in several changes of water and scud on the flesh and grain side (flesh is the side facing the muscle membrane, the side you see when the animal is living is the grain side). It will only suspend so much in water before some lime drops out and falls to the bottom of the bucking container where as lye is pretty much infinitely soluble in water and can get much higher PH solution. The hides must be bucked, it has been the advice from every tanner I've heard to use lime because it is impossible to get the PH too high with lime. Veg tan requires small effort every day or more to produce quality leather. I have several gallons of shredded willow waiting to be simmered and an 8 gallon stainless flame safe stock pot to do it in. There is material you can read on what properties different barks yield available online in various places. Any oak, sumac (except the poison kind obviously), walnut, birch, chestnut, tea leaves and even fir have tannins among thousands of others desirable in small scale vegetable tan. Historic tanneries would often mix tanning media to get a desired property or color also. ![]() He uses an oak species actually called tan oak because it produces such beautiful leather and has a very thick tannin rich bark. I saw a mention of Skillcult in your tanning thread, he is where I got a good deal of my information.
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