June 20, 2011

Alum Tanning

The alum tanning process did not successfully tan the first test strip. The test strip remained cream colored and rubbery. It was unclear whether the alum tanning process did not work or if the test strip was not properly bated. The third test strip will be used to determine which process did not work.

Vegetable Tanning

The second test strip was left in the vegetable tanning solution. This piece has become deeper in color.

Dehairing

Hair was removed from the 3rd test strip.

Soaking

The third test strip was soaked in distilled water to remove the sodium hydroxide.

Baiting
6 g of pepsin were added to 600 mL of distilled water and 18 mL of acetic acid. This solution was heated to 37°C. The third test strip was placed in this solution and the hot plate's magnetic stirrer was used to stirr the solution.

June 17, 2011

Alum Tanning
Alum tanning paste was removed from the first test strip and the final layer of tanning paste was applied. This layer will be left on for 3 days.

Vegetable Tanning

The second test strip was left in the vegetable tanning solution.

Overnight the piece of hide had changed in from cream colored to burnt orange. It had also become slightly tougher and more dimensionally stable.

Liming

The third test strip was removed from the distilled water and placed in a solution of 200 mL of distilled water and 2g of sodium hydroxide to loosen the hair from the hide.

June 16, 2011

Alum Tanning

The alum tanning paste was scraped from the first test strip and a new layer was applied.

Vegetable Tanning

300 mL of distilled water was combined with 100 mL of quercitannic acid solution obtained by soaking oak bark in distilled water. The second test strip was added to this solution. I plan to gradually increase the concentration of the solution to which this strip is exposed.

Trimming

A third test strip was cut from the large hide

Soaking 

The third test strip was placed in distilled water to remove salt and blood.

June 15, 2011

Alum Tanning

The alum tanning paste was again removed from the first test strip and another layer was applied.

Baiting
The second test strip was baited again. This time, 500 mL of distilled water was mixed with 5g of pepsin and 18 mL of acetic acid (CH₃COOH) to reduce the pH of the solution. This solution was heated to 37°C. After several hours the sample was removed from the heat and observed. The fatty layer that had been on the flesh side of the test strip seemed to be mostly removed. 

June 14, 2011

Alum Tanning

Alum tanning paste was gently scraped from the fist test strip. A new layer was applied and the strip was placed back in the beaker.


Baiting

The second test strip was placed in a solution of 500 mL of distilled water and 5 g of pepsin and heated to 37°C. After several hours it became clear that the bating process was not working so I will try again tomorrow.

June 13, 2011

Pickling 

The first test strip was removed from the bating solution and placed in a solution of CH₃COOH (acetic acid) and H₂O with a pH of 4.5 to lower the pH of the hide in preparation for tanning. To create his solution 350 mL of H₂O was mixed with 15 mL of CH₃COOH. The hide remained in this solution for 2 hours. 

Alum Tanning

90 mL of H₂O, 30 g of unbleached flour, 30 g of NaCl, 30 g of KAl(SO₄)₂^.12 H₂O (Alum),  and 15 mL of egg yolk (one egg yolk) were combined to form a paste. 

This solution was applied to the test strip.


Dehairing
The second test strip was removed from liming solution and hair was removed in the same manner as was used for the first test strip.


Soaking 

The second test strip was soaked in water to stop the liming process.


Vegetable Tannins

The oak bark pieces were removed from the solution in which they were soaking. 

June 11, 2011

Baiting
The test strip in the pepsin solution was left in solution to continue digestion of unwanted proteins.

Liming

The second test strip was placed in an NaOH solution of 200 mL of H₂O and 2 g of NaOH. The solution had a pH of 10. The test strip was left in solution overnight to loosen the hair.