http://www.vandykestaxidermy.com/Lutan-F-Tan-W130.aspx thats how I have always done it.Outdoor Hub mobile, the outdoor information engine
Before posting instructions from suppliers , could you please check with someone with a chemistry background as to wether you are posting the correct info ! This subject has been discussed MANY times so try using the search function !
Quoted from the breakthrough mammal taxidermy manual: "Pickled skins are too acidic to be tanned. If they were placed directly in a tanning solution, the ionized skin protein would attract the tanning chemical to rapidly resulting in a barrier, or surface tan. This is a rapid build up of chemical on the surface of the leather which prohibits complete penetration of the agent resulting in a poor tan, or no tan at all on the inside. Therefore they are neutralized in a solution of 1 oz of sodium bicarbonate (backing soda)per gallon of water."I'm sticking with the way I've been doing it, which is by van dyke's instructions. I come out with a white colored leather skin, no slippage, smell, rot or anything else that would indicate that's it' not tanned.