Low Water Immersion Dyeing is usually done using Procion MX dyes. There are also Procion H dyes but those are not what we want, since they work differently.
These dyes come in a powdered form that you mix with water for a dye concentrate you then use in various amounts to obtain the color fabric you want.
Procion MX dyes work on plant fibers by bonding to them in a chemical reaction. They actually become part of the fiber which is what makes them so colorfast. They are used on plant fibers (if you want to dye wool you use a different type of dye). They have the advantage of working at lower temperatures (70-110 degrees). Once mixed with water they are classified as non-toxic. This does NOT mean they are edible.
The chemical bond actually begins when the PH of the water reaches the appropriate level. This is done by adding Soda Ash to alter the water's PH level. A more complete explanation can be found here:
http://www.dharmatrading.com/batik/info/dye_chemistry.html
Okay, enough of the chemistry. Dyeing is messy and has some potential hazards, so you will need a variety of equipment to keep yourself safe and avoid making your life more colorful than you intend.
There are a few things that are MUSTS.
You must have a mask to wear while mixing the dye concentrates. The mask needs to be NIOSH/MSHA approved for dust and mist. Inhaling the dye powder is bad. Let me repeat that for emphasis. Inhaling the dye powder is BAD.
You must have a set of saftey goggles or glasses.
You will need measuring spoons and measuring cups. These should only be used for dyeing and never for food. These should be plastic to keep the cost low and to avoid breakage. I don't know for sure but since plastic is always recommended, metal might react with some of the dyes as well.
You need containers to hold the dye concentrates after they are mixed with water. I used old plastic water bottles because they are basically free and I can mix a good amount of the dye in them. I use the 1 liter bottles.
You will need something to do the actual dyeing of the cloth in. I have plastic buckets I use for larger amounts of cloth, but for most of my dyeing I use hefty OneZip Jumbo 2 1/2 gallon bags. The easily hold up to two yards of cloth and I reuse them so the cost is kept down. I started using them to keep the mess more contained.
You will need a container for the soda ash solution. I use a 1 gallon plastic water jug, again because they are cheap.
You will need rubber gloves. Right now I use the disposable surgeons gloves, mostly because I can manipulate better with these than the heavier rubber gloves. If you get the dye on your skin it will stain and you may be colorful for several days if you get a lot on you.
You will need a funnel or two. I just bought a set that had multiple sizes. These should be plastic.
In the next post I'll talk about the rest of the items you will need. Including the dye and other chemicals.
Please post any comments and questions!