I've been reviewing your site to educate myself in garment dyeing so I can dye a cotton skirt.  I decided to tub dye and I presoaked it in soda ash, then put the dye and salt in a bucket and then added some additional soda ash per the instructions on the little bottle of dye I bought from  
mister art.

Well, the color is perfect, but it is blotchy.  My questions to you are:

Do I have to presoak it again in the soda ash when I re-dye it?
Do I need to add salt?
Do I need to add the soda ash after 20 minutes as per the instructions?
I'm going to try this time in my washing machine, is there anything else I can do to have the color come out even?

Thank you for your time.  Your website is fabulous and very helpful.

First, what is the brand name of the dye you bought from mister art?  
What does the label say?

It's Procion MX dye, chocolate brown.  

That should work well. It does take an awful lot of stirring to get a smooth color by dyeing a garment in a bucket. Lots of extra water, too. Washing machine dyeing makes it a lot easier to get a solid color, since the machine does the stirring for you.

It's difficult to cover up a severe case of blotchiness, because the dark parts will stay darker and the light parts lighter, though both will be darker than before. The problem is similar to the Bleach Spot Problem. Large amounts of dye in a dark color can do it, or you can use Rit Color Remover (you'll need several packets in the washing machine) to lighten the skirt before trying again.

I should point out that there are also other possible causes of blotchiness: permanent press or stain-resistant finishes, invisible flaws in the fabric, or inadequate prewashing. Inadequate stirring is the most likely, however.

Once a garment has been washed out, the soda ash is all gone, so you will have to add more when dyeing it again. For dyeing in a bucket or washing machine, salt is necessary also, because otherwise too much of the dye stays in the water instead of going onto the fabric. Basically, the procedure for overdyeing a garment is exactly like dyeing it for the first time.

Be sure to get enough dye for your washing machine. A 16- or 20-gallon washing machine load requires more dye than a 5-gallon bucket. Check the required quantities for salt, soda ash, and dye. See the different recipes linked to on "How can I dye clothing or fabric in the washing machine?".

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