July 22, 2011

Baiting
The large test strips were baited for the 4th day at 37 C. After 2 hours two of the large test strips were removed from the baiting solution and one was left in the solution to continue baiting. The removed test strips were placed in distilled water to soak.

Vegetable tanning-
Staghorn Sumac

Fragrant Sumac

Sumac solutions of different concentrations were made from each of the two sumac species solutions as follows:

15%: 30 mL of sumac tannin solution was combined with 170 mL of water.
20%: 40 mL of sumac tannin solution was combined with 160 mL of water.
25%: 50 mL of sumac tannin solution was combined with 150 mL of water.
30%: 60 mL of sumac tannin solution was combined with 140 mL of water.
50%: 100 mL of sumac tannin solution was combined with 100 mL of water.
100%: 200 mL of sumac tannin solution was combined with 0 mL of water.
The baited hide pieces were cut into 10 pieces approximately 2''x3". One piece was added to each different solution. These pieces will help to determine the proper concentration for tanning with these sumac species.

Vegetable Tanning- Oak bark
The remaining test strips in the oak bark solutions were left in the solution to continue tanning.

The test strip that had been tanned in the 100% oak bark solution was oiled with olive oil and left to dry.

July 21, 2011

Baiting
The pepsin solution was reheated to 37 C to continue to bait the large pieces of hide. The solution was stirred using the magnetic hot plate stirrer.

Vegetable Tanning
The test strips being tanned in different concentrations of oak bark solution were left to continue tanning.

July 20, 2011

Baiting
The pepsin solution with the test strips was heated to 37 C and stirred with a magnetic stirrer.

Alum Tanning
The piece of hide in the alum tanning solution was removed from the solution, rinsed, and left to dry. It is unclear whether the alum tanning process worked. The hide appears to be more opaque and slightly more dimensionally stable, however it does not appear to have leather-like qualities.

Vegetable Tanning
The piece of hide that was in the 100% oak bark tannin solution was removed from the solution, rinsed and left to dry. The pieces of hide in other concentrations were left in solution to continue tanning.

July 19, 2011

Baiting

The large pieces of hide were removed from the distilled water and placed in a baiting solution of 3000 mL of distilled water, 30 g of pepsin, and 30 mL of acetic acid. This solution was heated to 37 C.

Alum Tanning
The test strip was left in the alum tanning solution.

Vegetable Tanning- Oak Bark
The pieces of hide being vegetable tanned were left in solution to continue tanning.

July 18, 2011

Dehairing
The hair was removed from the large pieces of hide. These pieces were put in distilled water to remove NaOH from their surface.

Alum Tanning
The test strip in the alum tanning solution was left in solution to continue tanning.

Vegetable Tanning- Oak bark
The test strips in different concentrations of oak bark solution were left to continue tanning.

July 15, 2011

Alum Tanning
The half of the third test strip was left in the alum tanning solution

Vegetable Tanning
Oak
Oak bark tannin solutions were remade to provide more tannic acid for each test strip.
10%- 20 mL of oak bark solution was mixed with 180 mL of distilled water.
15%- 30 mL of oak bark solution was mixed with 170 mL of distilled water.
20%- 40 mL of oak bark solution was mixed with 160 mL of distilled water.
25%- 50 mL of oak bark solution was mixed with 150 mL of distilled water.
50%- 100 mL of oak bark solution was mixed with 100 mL of distilled water.
100%- 200 mL of oak bark solution was mixed with 0 mL of distilled water.
The test strips were returned to their corresponding tannin solution.

Liming
The large test strips were moved from the distilled water to a solution of 3000 mL of distilled water and 30 g of NaOH

July 14, 2011

Soaking

Three large pieces of hide were cut for test strips and soaked in distilled water. They will be used for tanning with sumac leaves

Alum Tanning
No Change

Vegetable Tanning
No Change

July 13, 2011

Vegetable Tanning
Sumac:
Today we met with Dr. Frett of UD's school of Agriculture and Natural Resources to discuss natural dyes he is growing. We got to see Japanese Indigo (Polygonum tintorium) and Goldenrod (Solidago). He also gave us two types of sumac, Fragrant Sumac (Rhus aromatica) and Staghorn Sumac (Rhus typhina), that can be used for vegetable tanning. I removed the leaves from some of the sumac and soaked each sumac species' leaves separately in distilled water.

Rhus aromatica:

Rhus typhina:

Oak
The various concentrations of oak bark tannin were left to continue the tanning process.

Alum Tanning
The piece of hide in the alum tanning solution was left to continue tanning.

July 12, 2011

Vegetable Tanning
To test the concentration at which goat hide will be best tanned with oak bark, I used the oak bark solution created yesterday. I prepared solutions ranging in concentration from 10%-100% oak bark solution as follows:

10%- 20 mL of oak bark solution and 180 mL of distilled water.
15%- 30 mL of oak bark solution and 170 mL of distilled water.
20%- 40 mL of oak bark solution and 160 mL of distilled water.
25%- 50 mL of oak bark solution and 150 mL of distilled water.
50%- 100 mL of oak bark solution and 100 mL of distilled water.
100%- 200 mL of oak bark solution and 0 mL of distilled water.
To each of these solutions a piece of the large test strips were added.

Alum Tanning
The half of the third test strip in the alum tanning solution was left in solution to continue tanning.

July 11, 2011

Baiting

The large test strips were baited for the third time in the pepsin solution at 37 C. After several hours the fat had been removed from the pieces of hide and they were removed from the solution.

Soaking
The large test pieces were put in distilled water to remove the excess pepsin solution.

Debarking

Bark was removed from the oak branches using a draw knife to be used as a vegetable tannin. This bark was placed in distilled water to extract the tannins.

Alum Tanning
The piece of hide in the alum solution was left in solution to continue the tanning process.

July 9, 2011

Baiting
The large test strips were baited in the pepsin solution for 4 hours at 37 C.

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.

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.

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.

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.

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.

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.