Step1
Wash the hide with dish soap, rinse well, then gently squeeze (do not wring) out excess water. Soak the hide in one gallon of water mixed with one cup of salt for an hour or so.
Step2
Mix one cup salt with two cups fireplace ash. Remove the pelt from the salt water, squeeze out the water, then lay it fur-side down and spread the salt/ash mixture all over the skin side until the mixture gets crumbly.
Step3
Fold the pelt lengthwise with the fur side out, then roll it up and place it in a gallon-sized freezer bag. Put it in the refrigerator for two weeks.
Step4
Remove the hide from the refrigerator, shake off the excess salt and ash, and place it fur side down on a solid surface. Scrape off the salt and ash with a dull knife--you'll also be scraping away a thin membrane covering the skin.
Step5
Mix 2 lbs. of salt with two gallons of water in the five gallon bucket and stir well. Then add the 8 oz., battery acid--be sure to put on your gloves and goggles first. Add the hide, stir again, then weight it down with a brick and let it sit in a warm room for a week.
Step6
Check to see if the hide is tanned by making a small slit in the thickest part with a sharp knife. If the tanning solution has penetrated all of the way and the color is uniform, the tanning is done. If not, let it sit another three days, then check again. Repeat as necessary.
Step7
Remove the hide from the tanning solution, wash it in a mild soap solution, then squeeze out the excess water. Nail the hide to a board and let it sit until almost dry and stiff but not hard. If it does get too dry (hard), re-wet it with water from a spray bottle.
Step8
Work the hide over a chair back, clothesline, or something similar. Pull it back and forth (with the skin side down) until it is entirely dry and soft.
Step9
Toss the softened hide in a clothes dryer with a few tennis balls or sneakers. Let it tumble around on the fluff (no heat) cycle for half an hour so it gets even softer and the fur fluffs up.
Step10
Use a wire brush to scrape away any bumps on the underside of the hide.