The weather here this spring has turned to be warmer/windier/and high humidity during this time of year.It is stormy out.I have hung the 2 bobcat hides inside the house to dry quicker in lower humidity.
For hair-on flat hides to salt like beaver and such you can lay them on a surface flesh side up on a slight slant to drain fluids.Use a fine salt...Not rock salt.Massage it into flesh side well.I buy canning salt...cheap....from grocery store.
Now that they are fiint dry I made my tanning bath solutions.Be sure your hide is fleshed very good before inserting into tanning bath and even before salting.
2 pound aluminum sulphate and 4 pound pickling salt into around 3 to 4 gallons of water in each bucket.Dizzolving it in hot half ration of water first.Then adding other half of cold water to cool water off.I like stronger solutions to reduce time the hide is wet.
I put each hide into it's own bath.
I estimate around 2 to 4 days for these thinner skinned bobcats or 6 to 8 days for a single deer hide or large beaver.This all depends on how big the individual hide is.You cannot ruin it by leaving it in an extra day,or by making the bath too strong,but I would reccommend to not leave it in bath much more than a week.
A natural hide is not an even thickness thickness leather anyway but needs to be left in there till the thickest part is tanned.
A good test is to cut a strip off at a thick edge.It should show white clear through it.Any difference of translucency color needs more time.
There are products out there from taxidermy catalogs to put in bath to deter bacteria but if your worried I would use 2 tablespoons of concentrated lysol into a solution of this size. That would be around a tablespoon to every gallon of water.
Stirring it or rearranging the position of each hide 3 to 4 times a day.