You have to use hydrated lime, or pickling lime, garden lime wont work. add around 12-15 cups in 12-15 gallon of water, it usually takes 4-7 days. Be sure to stir hides at least once a day or more if possible, just reach in and pull on the hair if it pulls easily it is ready to go. after removing the hair it is time to,
Rinsing / Neutralizing
Putting the hide in running water for two or three days is the easiest way to neutralize it.
If you are only doing a hide or two and you don't have access to a free source of running water so you can rinse for a couple of days, just get a box of baking soda and a bottle of vinegar.
Put enough water in a barrel to easily cover your hide with lots of room to stir it around. Put a double hand full of baking soda in for each 5 gals of water (don't worry you can't use too much). Put your hide in there for 8 hours. Dump that and do it again. The hide should look totally un-swollen now (if not, then do it one more time). Now rinse it in a bucket of plain water for an hour or so.
Now, put enough water to cover your hide in the barrel again and add 1/3 cup of vinegar for each 5 gals. of water and soak your hide in that for 1/2 hour to overnight, then your rawhide is ready.
I like to put it on stretching frame stretch tight and then scrape both sides, it will loosen so re-stretch and repeat until desired thickness is achieved.