Tanning the hides of animals, which is their true skin and fur that covers the inner flesh, transforms the raw hide into leather. Leather is a valuable material with uses as clothing, bedding, saddlery, footwear, and more. Also, tanning a hide into leather uses up valuable resources from a hunted animal that would otherwise go to waste. Before tanning a hide, remember to cure and clean the hide for best results and to choose a inexpensive hide to learn tanning on.
Set out a container that is not metallic and can hold more than 1 gallon of substance. Pour 1 gallon of water into the container and add 1 lb. of ammonia or potash alum.
Pour 1/2 gallon of water into a separate container, which does not need to hold as much substance. In this smaller container, add 4 oz. of washing soda -- otherwise known as crystallized sodium carbonate, and available in the laundry aisle of most stores. Also pour in 8 oz. of salt.
Pour the salt, washing soda and water mixture into the larger container that has the water and alum in it. Pour very slowly and actively stir it into the larger container with a mixing spoon. Slow pouring prevents the resulting foam from overflowing.
Add flour to the mixture and mix it in until the solution develops the consistency of a thin paste. Do this by adding small amounts of flour one at a time with a tiny splash of water and plenty of stirring to obtain a smooth solution without lumps.
Lay out the hide on a working table or a large piece of plywood and tack it down to the board so that it's spread out and lays completely flat, with the hair side facing downward.
Coat the flesh-side of the hide with the paste, using a brush or scraper knife, so the paste piles up to a thickness of 1/8 inch. Let the paste sit for a day.
Scrape the paste off of the hide the next day with a scraper knife. Reapply another coat, just as before, and let it sit for another 24-hour period. Scrape off this second coat of paste the next day and reapply a third coat. Repeat this process until you have applied three coats over as many days. Leave the final coat to sit for 3 or 4 days. Scrape the final coat off with a scraper knife at the end of the period.
Soak the hide in the tanning solution without adding any flour to the mixture, if the hide does not have fur on the other side. In this instance, let the hide sit in the solution for 2 to 5 days, entirely submerged.
Dispose of the tanning solution and rinse out the non-metal container with a hose. Fill the container with 1 gallon of water and 1 oz. of Borax. After the hide receives the tanning solution or flour paste treatment, place the hide in the water and Borax mixture to rinse it off.
Pour out the Borax mixture and refill the container with 1 gallon of clean water. Rinse the hide once again in the water.
Spread the hide on the plywood or a working table and tack it in place so that it lies flat. Use the dull side of a knife to push out the water with firm strokes, using plenty of pressure.