I mixed up a 12 gallon vat, using pre-reduced Indigo from Pro Chem, mixed with Thiox and Soda Ash. I had heard that there is far more foam with soda ash…YES, there is much more foam.
This vat, following the directions from Pro Chem, was a much deeper blue than we used in Dagmar Klos’ class. A one minute soak for the wool yarn, gave a good medium blue. Silk was almost intantaneous. Linen went deep blue very quickly.
Managing the scum was difficult. We kept removing it to the side vats…but even so, we had plenty of spots.
We only worked, maybe, 2 to 3 hours and felt like we had been hauling rocks all day.