Bark-tanned Sheepskin Rug
Team Extracts/Powders: When you take out a gallon of “spent bark-liquor” today, you can use that same gallon of spent liquor to extract your next 1-pound of extract. This way, you'll be circulating the slow tannins back into the game.
Day 5 of Bark-liquoring
By Day 5, our hides have taken on a lot of colour, indicating tannin absorption. They may even feel “leathery” by now.
Time to scud!
Scudding is just wet-scraping on the membrane side of a hide, when the hide is partially bark-tanned. See the video “Recording Week 4” for a live demo of scudding.
Now is a good time to cut a little piece of your sheep skin off - at the neck, the thickest part - to see how far tannins have absorbed. Cut the piece, look at it sideways, and you’ll see tannins making their way through to the centre. After looking at a piece from the neck, cut a piece from the belly (thinnest part).
At the end of Day 5, you’ve now put 5lbs of tannin extract into your bark-liquor. You may have enough tannins in the bark-liquor for the hide to finish to become leather. Or, you might need a little bit more. In the meantime, keep turning your hide every day, twice a day.
Bark-liquoring Schedule, Days 6 to 18
I recommend scudding hides every 3-5 days. For the sake of simplicity, let’s say you’re going to scud every 5 days.
That means the next (2nd) time you scud will be on Day 10. This would be Tuesday, March 4 or whatever day is Day 10 for you.
The last (3rd) time you scud would be Day 15. This would be Sunday, March 9 or whatever day is Day 15 for you.
Here’s what we’re going to do:
On Day 10, you’ll scud. You’ll cut a piece of hide off at the neck. You’ll check out the cross section and see how advanced the tanning is.
(1) If the inside of your hide is just big, bright, white ~ with a minority tannin absorption ~ then you will make a fresh extract of 1:1 bark-liquor with the remaining 5 lbs of your tannin powder. Swap out 5 gallons of spent solution for 5 gallons of this fresh extract. You now have a super-strong solution that will pressure the hide into becoming leather. (Of note: I don’t think most folks will be doing this option, because extracts are powerful :).
(2) If the inside of your hide has a thin white line ~ with a majority of tannin absorption ~ then you will make a fresh extract of 1:1 bark liquor with 2.5 lbs of your tannin powder. Swap out 2.5 gallons of spent solution for 2.5 gallons of this fresh extract. You now have a strong solution that will pressure the hide into becoming leather. You will continue to stir + track your hide until Day 15. If on Day 15, you cut a piece of hide and it looks raw on the inside, you have a back-up of 2.5 lbs tannin powder in case you need it.
Please note: the above timelines are predicated on the baseline that the hide is being stirred often + is kept warm. If the hide is not stirred or kept warm, tanning will slow down. You’ll then need to adjust accordingly, because your spent solution will be higher in tannin (because the tannins won’t have had a chance to absorb into the hide yet). Email me if you have any questions.