Vat Dying in a Washing Machine
Disclaimer: We've been selling dye for years and years. In that time, we've never heard of a case where our dyes have "ruined" a washing machine. Just as our dyes do not stick to polyester fabric, they should not stick to the plastics or to the enameled metal of your washing machine. We use our washing machine all the time for dye projects, and have never had a problem. The natural step of washing the loose dye from your dye project after you are done dyeing it, should also clean out most of the loose dye from your washing machine. Just be sure to check after any dye project is complete, that all loose dye is rinsed from the machine before the machine is used for washing clothes. Since we are not experts in all materials used in washing machine construction, we make no guarantee that using our dyes in your particular washing machine will not harm or discolor your washing machine.
Step 1. Fill your washing machine with enough warm water to cover the fabric.
Note A: These are "cold water dyes." Which in the world of dyeing, means you use warm water. 105 degrees F. is considered ideal. But these dyes work well under a fairly wide range of temperatures so don't concern yourself with getting an ideal 105-degree bath. Just remember, you are dealing with a chemical reaction. And any chemical reaction happens faster the warmer it is. Very cold water may not allow the chemical reaction to occur at all, and should not be used.
Note B: The more water you have in the washing machine, the more diluted the dye will be, and the lighter the shade will be. However, if you have so little water in the machine that the fabric cannot flow freely through the water, the color may come out uneven on the fabric. I have found that dyeing fabric in the washing machine forces you to use more dye to get deep shades than "standard" recipes call for.
Standard dye recipes are: Deep shades, 1 oz. or more dye per pound of dry fabric. Medium shades, 1/2 oz. dye per pound of dry fabric. Light shades, 1/4 oz. or less dye per pound of dry fabric.
Step 2: Add dye powder to water in washer. Shut lid to agitate and dissolve dye.
Step 3. Add fabric to be dyed to the "dye bath" in the washing machine. Shut lid and allow to agitate for about 10 minutes. Note: Pay attention to the washing machine. You do NOT want the wash cycle to end and the dye to drain out. You need to keep resetting your washing machine to the beginning of the wash cycle through out the dyeing process so the DYE DOES NOT DRAIN OUT until you are ready for it to drain out.
Step 4. If desired, add salt to machine. Adding salt to the dye bath makes the fabric dye stronger because it forces the dye out of the water and into the fabric. Salt does not set the dye. It just makes dye migrate out of the water and into the fabric. Add the desired amount of salt in 3 steps. For example, if you want to add a total of 1-cup salt, first add 1/3 cup to dye bath. Close lid and agitate for 5 minutes. Then add second 1/3 cup. Close lid and agitate for 5 more minutes. Then add final 1/3 cup salt. Close lid and agitate for another 5 minutes. Note. I am not comfortable adding huge amounts of salt to my washing machine. Standard dye recipes call for up to 100% of fabric weight in salt to be added to dye bath for deep shades. That means for example that if you were dyeing 8 pounds of fabric in your machine, you would add 8 pounds of salt to the mixture. There is no way I would pour 8 pounds of salt into my washing machine. For deep shades, I normally add 2-4 cups salt to the mixture. You decide how much salt you want to add to your washing machine. The more salt you add, the deeper the shade will be. For light shades, I don't add any salt. But I do increase the agitation time by 15 minutes during this step so the color comes out more even. (The same amount of time it would take if you were adding salt.) Remember; keep resetting your washer to the beginning of the wash cycle so the dye bath does not drain out.
Step 5. Add dye fixer to the mixture. Add dye fixer just like you added the salt, slowly, a little at a time. Standard dye recipes call for about 2 1/2 oz. dye fixer for each pound of dry fabric dyed. In a washing machine load, I would add about 8 ounces (about 3/4 cup) to even the smallest dye project because washing machines contain so much water. Add 1/4 total amount of dye fixer to dye bath. Close machine lid and allow to agitate for 5 minutes. Add the next 1/4 total amount of dye fixer. Let agitate for 5 minutes. Add last 1/2 total amount of dye fixer. Let agitate 5 minutes.
Step 6. Reset washing machine to beginning of the longest wash cycle (about 15 min.) (dye bath is still in the machine.) Now you can let the machine run and not pay attention to it until it shuts off. The machine will agitate the fabric in the dye bath for the length of the wash cycle. The dye bath will then drain out and the machine will begin to go through rinse and spin cycles. You are now finished with the dyeing part of your project. Your final task is to now wash out all the loose dye that did not fix to the fabric.
Step 7. Leave dyed fabric in the washing machine. Fill machine with warm water and wash as you normally would a load of laundry. Do not use soap on the first washing. After the fabric is washed once, leave the fabric in machine. Fill again with warm (or hot water if you wish) and wash fabric again, this time adding fabric detergent or synthrapol detergent to the wash cycle. Wash fabric as many times as you need to in order to remove all loose dye. You can tell you've washed out the loose dye when you look into the washer during a rinse cycle, and the water is clear. After you wash out all the loose dye, no more dye should come off the fabric and you should be able to wash the fabric as you normally would any other colorfast fabric. If you are not sure if you've washed out all the loose dye, wash separately until you are sure.