Sounds like Tubari needs to work on their "Tanning Solution", maybe a bit too strong on their Alkalies.
(Bruce, they might look better if you were to have them Sheared.)
Doug
Beaver hats were fashioned from felt made from the thick underfur. Hats made of beaver fur were more water resistant than ones made of other materials, because the fur was adapted to being wet and dried repeatedly. Unfortunately, the process required the use of mercury, which is a toxic substance that affects the nervous system. Hatmakers often developed mental problems, which led to use of the phrase “mad as a hatter.”
"Acids have relatively little action on the hair, when applied in dilute solutions. The scales of the cuticle or epithelium are somewhat opened, the fibre becoming slightly roughened thereby. Even at high temperatures, the hair is quite resistant to the action of dilute acids. Concentrated acids destroy the hair with the liberation or formation of ammonia, hydrogen sulphide, and various amino acids. When treated with dilute acids, the hair, especially if it is of a very woolly nature, retains considerable quantities of acid, this phenomenon being probably due to the fixation of the acid by the basic groups in the hair. Nitric acid produces a yellow coloration when applied in dilute solution for a short time. Sulphurous acid, the acid formed by the burning of sulphur, has a bleaching action on the hair.
Alkalies attack the hair, even in dilute solutions, and by longer action complete decomposition sets in, with formation of ammonia and amino-acids. Ammonium carbonate, soap, and borax are practically harmless in their effect on the hair. Sodium and potassium carbonates roughen the hair on prolonged action, even in dilute solutions. Calcium hydroxide on continued action removes sulphur from the hair, causing it to become brittle."........Principles and Practice of Fur Dressing and Fur Dyeing, by William E. Austin (Consulting Chemist to the Fur Industry) 1923