Acid rot

Submitted by Terri on 9/6/05 at 2:32 PM. ( )

I'm trying to understand what acid rot is and why it happens. So far I have come up with, hides that have been tanned with Alum and dried but not mounted will rot if left exposed to air.

If not rehydrated will they eventually fall apart like the ones that have been rehydrated?

Will hides that have been wet tanned with Alum and mounted right away have this trouble with acid rot?

Thanks in advance for your help.


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Terri, I read your post the other day.

This response submitted by Glen Conley on 9/6/05 at 3:04 PM. ( )

The answers you are looking for are not quite as simple as can be explained in a sentence or two, or in a paragraph or two. There are more variables than most want to acknowledge.

First thing you will need to do is to get a grasp of what skin structure is, down to and including the molecular level, as that is indeed what we are working with and looking at here.

I have hours worth of reading and micro photography available on If you are a person capable of conceptual thinking, you will be able to sort out a lot of your own answers.

One of the things I have not touched on in any of those articles is hygroscopic properties of chemicals, and the nature of various acids to either convert, or to take their own form as a salt, that will give you another group of leads to run down.

As soon as possible, I am going to get George Roof and Bill Yox involved in a simple little project. They didn't know that until now. The idea for this one did come off your previous post. We'll see if we can't sort out some fact from BS. Either that, or I will be proven wrong in my thinking.


This response submitted by Terri on 9/6/05 at 3:27 PM. ( )

Thanks Glen. I will do some reading on your website.

Hope to get a better understanding of the whole tanning process.

I appreciate you help.



This response submitted by David Patton on 9/6/05 at 5:01 PM. ( )

Please keep us posted on the results of the project. I have a suspicion that the results will confirm my thoughts on acid rot...incomplete neutralization from the tannery. I know this one has been beaten all about the head and shoulders with several competing ideas on the subject. I also know that it hits home to tanneries that make a living from the aluminum sulphate type tans. So, it will be interesting to see what your project uncovers.

BTW, you can get an alum tan without using the sulphates. That eliminates the humidity/sulphuric acid theory. Just thought people might want to chew on that one a little.


acid rot

This response submitted by ej on 9/6/05 at 11:14 PM. ( [] )

may it not be possible to get the leather too neutralized. too base? most tans work at 4 ph. and we go up to 5 when ending the tan, going into the fat liquoring.


This response submitted by oldshaver on 9/7/05 at 8:09 PM. ( )

Just let a un-disolved hunk of soda come in contact with a skin overnight, and see what happens. The area affected, will fall appart in your hands . In my opinion, a ph too high, is far worse on a skin, than one too low.

high ph

This response submitted by ej on 9/7/05 at 10:10 PM. ( [] )

your right old spice. but i did not say to do that.


This response submitted by os on 9/8/05 at 7:00 PM. ( )

I know you didnt.

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