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Anyone know of a citric acid formula based on dry hide weight?

Discussion in 'Tanning' started by agua3777, Sep 7, 2016.

  1. I'm sure I read one years ago, but can't find it anywhere. I'm trying to find a formula that will give me a ballpark estimate of how much citric acid would be required in a pickle for various combinations of hides based upon total dry weight. If memory serves me it was approx 3 oz. per pound of dry hide. However, my current pickle is 3.5 oz per pound of dry hide and the ph has risen faster than I normally experience when pickling a deer, elk or coyote by itself.
    Here's what I have...
    Four raccoons weighing a total of 7.2 lbs. dry salted. I rounded up to 8 lbs. (to provide a little extra) and mixed an 8 gallon pickle @ 3oz. citric per gallon. Added an extra oz. to adjust starting ph to 1.0, giving me a total of 25 oz. at start. Salinity at 44, also required an addition 1/2 lb. salt beyond the typical 1 lb. per gallon.
    I'm 18 hrs. into this pickle and the ph has already risen to 2.0, acceptable but high enough to concern me if it hasn't stabilized. I'll monitor closely today and adjust as needed.
    My interest is founded in streamlining my tanning process, but I don't want to compromise quality for effiecency. If anyone is aware of a baseline formula or has other experience to offer, please chime in. Thanks.
     
  2. 3bears

    3bears Well-Known Member

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    I'm sorry I can't help you but I have a question. Isn't 8 gallons of pickle for 4 coons too little? I'm not a tanning expert but, when I pickle just about anything, the minimum is 5 gallons per skin or cape, not just for ease of measuring but that way the skins are not cramped and can absorb the pickle easier.
     

  3. You may be right 3bears, time/results will tell. They seem to have plenty of free space for circulation without being bunched up. I'm using a 20 gal. tub and and as far as volume is concerned I think I could have reduced it by one or two gallons without crowding them. However, they're not large coons.
     
  4. Bruce_Rittel

    Bruce_Rittel Consultant Services

    I usually base my Pickleing, and Tanning solutions on WDSW (Wet Drained skin Weight) - it's more accurate because you now have the hair, fur and Wool weight involved, as well as the flesh weight too - which can vary with its thickness (before shaving). Weigh them after they're relaxed. Based on their weight i always figure 2 qts. of solution per 1 Lb. of WDSW. That way I know that they are not overcrowded in the solution and can be stirred easily. I'd not just mix up 5 Gls. of solution - but using their WDSW base their needed solution weight.

    As an example - for 30 Lbs. of WDSW I'd mix up 15 Gls. of each mix - for my Pickle and Tan! That way you don't waste your chemicals, and the skins will have plenty of room to let the solutions penetrate and be stirred - and be successfully Tanned!

    Citric Acid I always use 3 Ozs. per 1 Gl. of Pickle. The ph should always be between 1.5 and 2.5 to remain stable - but the thicker skins seem to absorb and raise your pH, so you need to keep an eye on them - pH wise! Simply add more Citric Acid. For normal Pickling, the 3 Oz./1 Gl. works good, but Pickling a Bison skin may bump up the pH - so check it to make sure and readjust it. As I said the skin may absorb some of the Acid!
     
  5. Bruce thank you very much for your response. it's always reassuring to get an answer from an expert in the field of question. Thanks for the clarity.
     
  6. 3bears

    3bears Well-Known Member

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    2,622
    MN
    Bruce, How do you know the WDSW until after you rehydrate/relax your skins? Are you referring to using 2 separate soaks?
     
  7. Bruce_Rittel

    Bruce_Rittel Consultant Services

    Use a bathroom scale - you don't have to be scientifically exact. After a short drain, Place the WDSW skins or capes in a 5 Gl. Pail and weigh them on the scale - your weight, plus the weight of the pail and the weight of the skins or capes you have. Now subtract your weight plus the empty 5 Gl. Pail to figure out their weight. Use this weight for mixing your Pickle and Tan solutions. 2 Qts. of Water to every 1 Lb. of WDSW weight. For Static Tanning it should be accurate enough.