Hi Boco. Using your tanning method for the first time. I have a hair off deer hide, several rats, otters, small beaver and coons currently in various stages. Nothing has been completely fished yet. During this process I ran into a couple of things.

When mixing the tanning solution (6 gallons), my ph would initially be around 3. I would then mix another half gallon of salt/washing soda and add it. I then had to do another. It took a bit before I could get the ph up to 4. With adding additional water/salt/washing soda, is there a point where I would need to add more Aluminum Sulphate?

In your instructions you said:
. Don't over oil the thin parts. How do you know if it is over-oiled? What happens?
. I had muskrats in the tanning with some otter/coon. I took them out at 3 days, leaving the others in yet. What happens if you keep hides in the tanning solution too long? Do they get damaged?

Aluminum sulfate,salt and water make acid.
The washing soda buffers it and brings the ph up.(weakens the acid)
Just keep checking with the ph strips if you want and adjust.Sounds like you did that.
Tanning should be between 4 and 5.
Overoiling will leave the leather oily and clammy,hard to rectify over oiling without using a solvent.
A little overoiling of the leather or oil in the fur can be rectified by washing and or drumming with a little solvent added to the media in the drum.
I keep different concentrations of tanning oil thinned with water on hand=75-25 oil to water for thicker hides 50-50 for medium hides and 25-75 for thin skins.
Adding some thinned oil after initial oiling is better than over oiling.

Unlike a pickle solution which can hold skins for a long long time (as long as the ph remains between 1 and 2),the skin could be negatively affected if left too long in a tan,
3-4 days should be no problem

I would reccommend tanning one or two hides at a time until you develop your tanning skills.
Too many at one time especially different species doesnt usually work out to good when you are learning.

Thanx Boco.

I've been hobby tanning now for several years. Probably only have 40 or so various hides under my belt, though. Was using ez-100 and my results ranged from excellent to not so good. Saw how good yours came out and figured I'd try your method. My initial round consisted of a hair-off deer hide, done and came out excellent, and 3 small coons which are being scrunched and are about 98% dry are looking good too.

I am looking at the rats I pulled out the other day. Just starting the scrunching process. Not sure about them. Out of all the hides I've done, my rats just never come out white and soft. Most end up a bit on the papery side. Just not sure what I'm doing wrong with them. Do you do anything different with muskrats? Any special tips?

All my coons and otters come out good. Beaver are pretty good, still need to work on my hide thinning. Muskrats not so good.

Rats can be tricky I think some get papery cause they dry too fast.
I have used dishsoap as an initial lube on rats and rolled them up leather to leather for several days and let them mostly dry that way.(takes a few days)
Then wash,tack out and give them a oiling with the thin oil ratio.

Thanx. I'll give that a try. The rats I'm working on now are slowly drying and the dry spots are coming out white using your method. I'll know more tomorrow.

Thank You for sharing all of your knowledge. It is very much appreciated.

No problem,happy to help.
Cats are pretty easy to tan as long as you shave down the thick leather in the neck shoulder area.