Bleaching Silk
Silk is a soft, delicate fabric that needs special care. This is particularly true if you need to bleach it. Chlorine bleach weakens or disintegrates certain fabrics and cannot be used on silk. Instead, hydrogen peroxide is a readily available substitute for chlorine bleach. Use peroxide to remove color from your silk.
IMPORTANT: Do not use an aluminum pot. Hydrogen peroxide reacts as a catalyst with aluminum inhibiting the bleaching process.
Step 1
Bring a pot of water to boil on the stove. Use a pot that is large enough to hold the silk, with room for it to move, and enough water to cover the silk. Remove the water from the stove, and let it cool to 140 degrees Fahrenheit.
Step 2
Dissolve 1/2 teaspoon soda ash in the water for every pound of fabric you are bleaching. Put the silk into the pot, and wash it in the hot water. Remove the fabric, and rinse it thoroughly with water.
Step 3
Fill a stainless steel pot with 7 1/2 tablespoons soda ash, and 6 pints of 3-percent hydrogen peroxide, which can be found at drugstores. Add 1 teaspoon of a professional textile detergent, which helps remove color and prepares fabric for dyeing.
Step 4
Put the pot on the stove, and heat it until it reaches 130 F.
Step 5
Put the silk into the mixture, and stir it with a wooden spoon to ensure the peroxide reaches all the fabric. Set a plate on top of the water to keep all the silk submerged. Leave the silk for 24 hours, so it will thoroughly bleach.
Step 6
Drain the fabric, and rinse it with warm water.
Step 7
Mix 11 tablespoons of white vinegar with 1 gallon of warm water. Put the silk in the solution for 10 minutes. Stir frequently to ensure the silk is evenly covered. This neutralizes the peroxide.
Step 8
Drain the silk, and rinse it well. It is now ready for dyeing or for use.
Info obtained from https://www.hunker.com/13422747/how-to-bleach-silk