Q: How do I protect my goods from the sediment at the bottom of my iron vat. Could you describe in more detail the ideal set-up for a basket or net that I could place in the indigo vat?
A: Yes, the sediment at the bottom of the indigo kit can bond to your piece of fabric and create what I’ll call a ‘false foundation’ upon which all future layers of indigo will bond. When finally washed out, all subsequent layers of indigo will rinse off when the sediment is eventually rinsed off.
If you get your piece into the sediment, make sure to rinse it thoroughly (you can also even use soap, scrubbing sponges or pressure from a hose to blast off the sediment) before dipping it back into the vat to layer on additional color. If the sediment contained a lot of fresh iron, it has the ability to tint your fabric yellowish/brownish where it comes in contact, even after thorough rinsing. To remove this stain, simply add a teaspoon of the citric acid powder included in the kit into a couple gallons of hot water, make sure it is dissolved and soak your pieces overnight (agitating when you remember to). Rinse your pieces until the rinse water comes clear and then resume dyeing.
To avoid all that hassle, you can get some sort of mesh bag (like an inexpensive synthetic mesh laundry sack, or even a layered piece of cheesecloth) and secure it to the rim of the vat and make sure that it only hangs about half way down the vat so that the pieces cannot go all the way to the bottom and make contact with the sediment. You can remove and rinse the bag when you replace the lid on your vat after dyeing.