Here is the indigo vat I made. I ordered some pre reduced indigo from ProChem in Fall River MA. I already had the thiox and the soda ash. I mixed it according to the directions from ProChem. The bubbly stuff is called the flower. It has a lot of concentrated indigo in it so I skim that off before dunking in the bound pieces and put it aside in a covered tupperware. When I have finished working with my vat, I will put the flower back on top.
Indigo oxidizes when the air hits it. The pieces come out a very light chartreuse green and then before your eyes turn deep indigo blue once oxygen gets to it. So you want to keep air out of the vat. Don’t let stuff float and squeeze out all you can under water (with gloves on of course!) Have something nearby you can drop the work on. I used a boot thing I got from a discount store.