Van Dyke Supply Co. is a company that I get supplies from. One of the products that I get from there is Citric Acid for pickling hides. Below is a description of the product and how it works.
Pickling Crystals (Chromium Sulfate)
(Citric Acid) Environmentally Friendly
Substitute Oxalic Sulfate or Formic Acid for Citric when tanning with Tannium (Chromium sulfate)
Prior to pickling
- It is highly advisable to flesh and salt the flesh side of hair on skins for 12 to 24 hours. Salting removes skin moisture and sets the hair. Wash skin(s) thoroughly after the salting period, prior to placing in pickling solution.
- Dissolve 3 oz pickling crystal, volume measure, and 1-pound of salt for ever gallon of hot water. Always remember to let the pickle solution cool to room temperature before placing the skin into it! Use a minimum of 5 gallons of pickle solution to pickle an average full shoulder deer cape. Use a minimum of 2 gallons pickle solution for a fox skin. Minimum pickle time for a deer cape is 72 hours. Pickling for and then refreshing the skin and returning it to the pickle for an additional 24-48 hours would assure a thoroughly pickled cape. Deer back hides may require 6-8 gallons of pickling solution depending upon the size of the hide. A good test to ensure your skin is pickled is as follows: squeeze hide between thumbnail and fore finger. The indention you make should remain in the skin. Continue pickling the skin if indention disappears. Do the indention test on several areas of the skin to ensure the entire skin area is pickle.
Neutralizing Pickled Skins
- Low pH of acid pickle in most cases ensures the killing of bacteria that causes hair slippage! However if the pH is too low prior to tanning, most tanning chemicals will rapidly fix to the skins surface with little or no penetration. The interior of the skin will become stiff on drying as a result of grain collapse. Neutralize pickled skin prior to tanning by using 1 oz of sodium bicarbonate (baking soda) per 1 gallon of water. Use a minimum of 1 gallon water for a fox skin, 2 to4 gallons for deer cape and back hides. Now the crucial part of neutralizing is the amount of time the skin is in the neutralizing solution. A good starting point would be to neutralize a fox skin for 5 minutes, remove and rinse. A deer cape for 10 to 15 minutes, remove and rinse. Over neutralizing pickled skins can result in slow and unfixing penetration of tannins. Neutralizing time again can and will vary depending upon amount of time pickling, kind of acid used and thickness of the skin. It is still always best to neutralize for a short interval! After neutralizing, rinse skin thoroughly and place in tanning solution. Neutralize used pickling solution be adding predissolved sodium bicarbonate into warm water and adding to pickle solution. Test with litmus paper. Solution should be neutral at a pH of 7. Start by using 1 oz if sodium bicarbonate per 5 gallon of used pickle. After neutralizing to a pH of 7 you may discard the solution. Use litmus paper foe testing pickles and tanning solutions.