battery acid tanning question

ok gang,,,,, I've tanned deer hides using battery acid....lots, ...but havn't done smaller skins........how long to leave a coon in the acid bath?? I don't wanna leave it in too long and destroy it.

I haven't tried coon with acid, but have done a bunch of muskrats and a couple mink, which I leave in the acid for 24 hours. The instructions I have for doing heavier skin, i.e., coon and beaver, say to leave them in there about 3 days. To check and see if they are completed... take a sharp scalpel knife, along the thicker part of the hide and slice a small slim strip off of the edge... if it has been in the bath long enough, the edge of the hide will be white clear through. If not it will have a thin part that is pink. I have several coon in freezer to do, but just haven't done them yet.

Garry-

What pH are you aiming for? I've used citric acid in the past.

I was under the impression that as long as you maintained the proper pH, a hide could remain in the acid indefinitely. Within reason obviously.

pH and salinity needs to be maintained. Purely acid and no salt can damage the fibers.

Is it impossible for you to get acid that is meant for tanning?

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There are many acids that can be, and are used for tanning; sulfuric being one of the most corrosive. Some of the other common acids used are; oxalic, citric, strong vinegar. Lactic acid has been used and you can't forget the original tannic acid derived from tree bark.

I like oxalic acid, it's strong but manageable.

The way you test to see if the skin has been in the pickle solution (water, acid and salt) long enough is to put an indent into a thick part of the skin with your thumb nail. If the imprint bounces right back out it's not done; the nail imprint should remain in the skin. The rinse and neutralize with baking soda and water.

BTW, keep your pH under 2.0

What pH are you neutralizing in and how long? This has been my hardest struggle. I made a batch of hats once that as I started working them my hands began tingling.

You forgot formic but it's best left alone because that crap will burn you out. Krowtanns formula is mostly a formicn acid pickle

I use about one tablespoon of baking soda per gallon of water. I rinse the skin first just to get out the excess pickle solution, wring it out then place in the neutralizing solution and keep it fairly well stirred for about 30 minutes. Then remove and rinse in clean water.

7pH is what you want to neutralize. And as said about 30 mins

Yes, and there are many things that can be used as a hammer. Lol.

There are many hammers that can be used as a hammer too.

One thing to remember, skins “tanned” with sulfuric (battery avid) will suck moisture out of the air and make your skins clammy.

technically a pickle not a tan.

The only difference between a pickle and a tan is the ph it is finished at.
Aluminum sulfate,salt and water makes sulfuric acid-if the skin remains at ph 1.5 to 2.0 it is a pickle.
You can use aluminum sulfate as a tan also-the ph needs to be raised to 4.0 to 4.5.by the addition of soda,then it is a tan and not a pickle.
Many commercial tans and some synthetic tans are "complexed" aluminum sulfate tans.There are compounds added to keep the tan fixed and not as succeptable to leaching out over time.A home tanner can do this by re tanning or combination tanning with vegetable or other things.
If a skin gets clammy in high humidity it means there are unwanted chemicals left in the leather.(not neutralized/stabilized).

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I used to do a chrome tan. Chrome tans are the most resistant to leaching out after getting wet. After being wet it doesn't stiffen up. Chrome tan doesn't create a stretchy leather though, and if you don't get the leather "broke" before it dries out you can't re-wet it very well. But chrome tan is great for things that get wet; where I trap it is common for the weather to warm up and your fur hat will get wet.

90% of leather today is chrome tanned.

I had considerd using the old " alum" tan .....but trying to find it in bulk without paying out the wazoo was the sticking point.........

Rittels safety acid works great and isn't dangerous like battery acid.

Chrome tan is good for leather but most people don't use it for fur products since it turns the leather bluish-green. It can be dyed thought, usually some shade of brown.

I was able to find a correct recipie that would give me a ph of around 1.5 using battery acid. from what I was told. "use 1/2 pound or 8 ounces of salt and 1/2 ounce by weight of battery acid or sulfuric acid you will end up with a pH of 1.2 and this is very desirable for properly charging the Hide for tanning and cleaning out the unwanted‘s ".