can anyone explain acid rot as I have had several hides acid rot from commerial tanners that I paid big bucks for fall apart How would I prevent ths when tanning my own skins
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acid rot is caused when an acid such as sulfuric was used in the pickle stage and didnt or couldnt be rinsed out of the hide or was not fully nutralized and therefore never stoped acting whithin the skin until the fibers break down and fail. Go with an acid such as SAFTEE-ACID from Rittel's and follow the instructions and you wont have any problems. To see a complete pre-tanning session, go to www.taxidermyreference.com and go to how to links and my article on succesful tanning and this will help you. Brad
When you have a skin tanned by using Aluminium sulfate, the
sulfuric base that is in alum may never get nuetralized, if you have
complete saturation of alum in the skin and the skin dries out in the
finishing process, what can happen is any moisture or humidity can
make the sulfuric from the aluminium sulfate or the pickle active and
there for start eating or eroding fibers in the skin (weaking the
structure) Thats why in our tans they are acid free, going with
Liqua Tan or Para Tan will most definitly increase your skins life.
Some Tanneries use Alum, some say that they can completly neutralize
the skin and tan, the ones that don't well this can happen. Select
tanneries that use a good quality tan and a good quality oil, if you
need some references please contact us, Also if you need a free technical
tanning hand book emial me for one with your address.
Mark Daniels
303-666-9045
Acid rot is caused by an acid that can take it's own salt form. The classic example would be oxalic acid. This is one of the old timer's acids used for furs and leather. It's crystaline form can be dissolved in water, the water is evaporated off and the acid has resumed it's crystal (salt) form. It's the same chemical principle as dissolving table salt in water and allowing the water to evaporate. The water evaporates and salt remains, add water and once again you have salt water. But in this case, the acid salts would be picking-up atmospheric moisture and then go back in to acid solution,doing a little more damage each time. Oxalic is but one example of the group of deliquescent acids (able to absorb atmospheric moisture). To test pieces of tanned skins for retained acids, trim off a finger nail clipping size piece and put two or three drops of distilled water on the trimming. Repeat this procedure, but use a baking soda-water solution on the second piece. If acids are retained, the distilled water treated piece will be greatly swollen by contrast. Excuse me, I neglected to point out that the trimmings need to be dried for the above tests. Regarding avoidance of this situation in in-house tanning, it is actually another chapter in it's self.