Baiting
The large test strips were baited in the pepsin solution for 4 hours at 37 C.
Saturday, July 16, 2011
Monday, July 11, 2011
July 8, 2011
Dehairing
The two large test strips were removed from the lime solution and the hair was removed from them.
Soaking
The test strips were then added to distilled water to remove excess NaOH.
Baiting
The test strips were added to a solution of 2500 mL of distilled water, 25 g of pepsin, and 40 mL of acetic acid. This solution was heated to 37 C and stirred with the magnetic stirrer on the hot plate. This process continued for 3 hours.
Alum Tanning
The alum paste was left on the test strip.
The alum solution with the other test strip was stirred to recombine the separated layers of the solution.
The two large test strips were removed from the lime solution and the hair was removed from them.
Soaking
The test strips were then added to distilled water to remove excess NaOH.
Baiting
The test strips were added to a solution of 2500 mL of distilled water, 25 g of pepsin, and 40 mL of acetic acid. This solution was heated to 37 C and stirred with the magnetic stirrer on the hot plate. This process continued for 3 hours.
Alum Tanning
The alum paste was left on the test strip.
The alum solution with the other test strip was stirred to recombine the separated layers of the solution.
July 7, 2011
Alum Tanning
The alum tanning solution was stirred because it had again separated into two layers. This test strip showed a slight change in appearance in that it was slightly less translucent.
The alum tanning paste was removed from the third test strip and a new layer was applied. This piece of hide appeared to be much more dimensionally stable than when first introduced to the alum tanning paste and was no longer shiny or translucent.
Liming
The large test strips were removed from the liming solution to remove the hair. The hides were not ready to be dehaired as the hair was not removed easily from the hide. These pieces were placed back in the liming solution and allowed to soak for another day.
The alum tanning solution was stirred because it had again separated into two layers. This test strip showed a slight change in appearance in that it was slightly less translucent.
The alum tanning paste was removed from the third test strip and a new layer was applied. This piece of hide appeared to be much more dimensionally stable than when first introduced to the alum tanning paste and was no longer shiny or translucent.
Liming
The large test strips were removed from the liming solution to remove the hair. The hides were not ready to be dehaired as the hair was not removed easily from the hide. These pieces were placed back in the liming solution and allowed to soak for another day.
July 6, 2011
Alum Tanning
The alum tanning paste was scraped from the test strip and a new layer of paste was applied.
The test strip in the alum solution was left in solution. The solution was stirred because it had separated into a clear layer on top and a cloudy layer on the bottom.
Liming
The two large test strips were added to a solution of 20 g of NaOH and 2000 mL of distilled water. This solution was left to sit over night.
The alum tanning paste was scraped from the test strip and a new layer of paste was applied.
The test strip in the alum solution was left in solution. The solution was stirred because it had separated into a clear layer on top and a cloudy layer on the bottom.
Liming
The two large test strips were added to a solution of 20 g of NaOH and 2000 mL of distilled water. This solution was left to sit over night.
July 5, 2011
Alum Tanning
56 g of alum was dissolved in 950 mL of distilled water. The resulting solution had a pH of 4. In a separate beaker, 28 g of sodium chloride and 14g of sodium carbonate were dissolved in 340 mL of distilled water. The pH of this solution was 6. Both solutions were clear. The second solution was added to the first and both were stirred together. The solution began to foam and turned milky white.
200 mL of this solution was poured into a smaller beaker. Half of the third test strip was added to this solution to be alum solution tanned.
150 mL of the alum tanning solution was added to a beaker and unbleached wheat flour was added until the solution became a paste. This paste was applied to the other half of test strip 3.
Vegetable Tanning
The second test strip was removed from the vegetable tannin solution and soaked in distilled water to remove excess tannins from the hide.
Soaking
Two large pieces of goat hide were placed in distilled water to soak.
Vegetable Tanning
Soaking
Two large pieces of goat hide were placed in distilled water to soak.
June 22, 2011
Baiting
The third test strip was again baited at 37 C. After 3 hours of baiting the test strip was removed from the pepsin solution. The hide was now extremely thin, delicate, and translucent. This test strip was then cut in two pieces. One half will be alum paste tanned and the other half will be alum solution tanned.
Pickling
Both halves of the third test strip were introduced to a solution of distilled water and acetic acid. This solution had a pH of 4. This process lowers the pH of the hide in preparation for the acidic tanning process.
Vegetable Tanning.
Although we had originally intended to gradually increase the concentration of the tanning solution to which the second test strip was exposed; the speed at which the test strip absorbed tannins from the solution was more rapid than we had expected. Therefore, we decided to keep the concentration of the tanning solution the same throughout the entire tanning process. I created a new tanning solution of the same concentration by combining 300 mL of distilled water with 100 mL of quercitannic acid solution extracted from oak bark. The second test strip was added to the new vegetable tanning solution and left to sit.
The third test strip was again baited at 37 C. After 3 hours of baiting the test strip was removed from the pepsin solution. The hide was now extremely thin, delicate, and translucent. This test strip was then cut in two pieces. One half will be alum paste tanned and the other half will be alum solution tanned.
Pickling
Both halves of the third test strip were introduced to a solution of distilled water and acetic acid. This solution had a pH of 4. This process lowers the pH of the hide in preparation for the acidic tanning process.
Vegetable Tanning.
Although we had originally intended to gradually increase the concentration of the tanning solution to which the second test strip was exposed; the speed at which the test strip absorbed tannins from the solution was more rapid than we had expected. Therefore, we decided to keep the concentration of the tanning solution the same throughout the entire tanning process. I created a new tanning solution of the same concentration by combining 300 mL of distilled water with 100 mL of quercitannic acid solution extracted from oak bark. The second test strip was added to the new vegetable tanning solution and left to sit.
June 21, 2011
Vegetable Tanning
The second test strip was left in the oak bark solution to continue the vegetable tanning process.
Baiting
The third test strip was baited in the same pepsin solution used on June 20th. The solution was heated to 37C and stirred a magnetic stirrer on a hot plate. The third test strip was baited for approximately 4 hours.
The second test strip was left in the oak bark solution to continue the vegetable tanning process.
Baiting
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