I know this has been discussed much and am sorry to subject all of you to this again. But....I have a finished quilt ready to be washed and have a couple questions. I didn't wash the fabrics beforehand (was pieced before I became educated) and don't want issues with bleeding fabrics. I read somewhere much earlier to use synthrapol but can't find it anywhere but online. I also read where someone posted that the original Dawn dish soap is almost identical to synthrapol and will accomplish the same thing - keeping the dye particles from settling into the fabrics. Am I correct? I really don't want to screw up this quilt.

I would not use Dawn on the quilt. Its a good grease remover , but as far as being identical to syntropol ...... I would not risk it.
You can get it as most any LQS . I have not seen it at any Jo Ann's. Dharma trading has it .

http://www.dharmatrading.com/html/eng/2127-AA.shtml

Not at any LQS in my area, nor Walmart or JoAnn's and need it today!

Call your local LQSs; many carry Synthrapol now.

Synthrapol has to be used in a *lot* of hot water. Don't try to use it in a domestic front loader; there isn't enough water. A laundromat front loader is okay, especially the big ones. A domestic top loader has enough water. The need for water is because, if there are loose dye particles, there has to be enough water for them to stay dispersed in; if water quantity is inadequate, extra dye particles will still settle in fabric. (As long as they are unset, they can still be removed in subsequent washings in Synthrapol, but who needs the agro?)

If you are using a top loader and want to be very "easy" on the quilt, do not allow it to agitate; instead, stop the machine during the agitation cycles and hand agitate by pushing down on the quilt, then skip to spin cycle. Since the water has to be hot, you probably want to wear thick rubber gloves for this to protect your hands.

I have read the Dawn substitute thing online for years but never could find the clear Dawn to try it out (*must* be the clear Dawn that looks like water; cannot be the blue Dawn!). Just recently I finally saw clear Dawn at Walmart.

Chances are your fabrics won't bleed, but using Synthrapol provides insurance.

Edit: I just did a quick Google search of websites for using Dawn as a substitute for Synthrapol. They all seem to be for dyers and specialized applications, such as washing silks prior to dying, or using a drop as a surfactant for dyes. There's no guarantee that Dawn will work the same way as Synthrapol does in terms of suspending unset dyes in water when washing a quilt.

Also, just wanted to mention that color catchers are fine for slight dye leaks but will not be enough if there is a major dye bleed when washing a quilt. It's fine to add color catchers to a Synthropol wash, but they will not provide the same amount of "insurance" that Synthrapol provides.

I bought a sheet you put into the washing machine to "catch" the colors...off the top of my head I can't remember the name but it came from Joann's...worked really well.

Color Catchers maybe?

are the fabrics you used hand dyes or batiks?
or red?
why do you think they will run?
first try a test- dampen the ones you think might bleed- and rub with a white paper towel (doesn't take much rubbing) if they will run you will know-
if nothing comes off on the paper-chances are they are not going to come off in the wash- and synthropol has to be used in hot-hot water- people seldom really wash their quilts that way- unless you find you do have a bleeder don't worry about it- wash it with cool/or warm water- toss in a color catcher just in case if it will make you feel better- and take it out the minute it is done (don't let it set wet crumpled on itself) and check it- if nothing is (amiss) toss it in the dryer-

if it does run at all you can wash it again before drying it- you can (spot treat) any small areas and rewash.

it is a whole different ball-park if it's made with batiks & hand dyes---they tend to run- sometimes for numerous washes- then you have to deal more...

I found a link that explains that regular Dawn dish soap (no bleach or fancy scents) achieves the same results as Synthrapol. Soooo....I took my trusty bottle of Dawn and the quilt and off to the laundry we go. Link said just a couple teaspoons would do it. I set the washer on hot and in the quilt went. It had some pretty dark reds and I was just a bit worried, but everything came out perfect. It washed up great! No bleeds anywhere. I will be using Dawn from now on.

Just out of curiosity, were any of the red fabrics runners? I mean, did you test them before you washed them as ckcowl suggested? Because if they weren't runners to begin with, then the Dawn didn't really do anything to suspend any dye and it may not actually work for that purpose at all. So next time, if the fabrics ARE runners, you may find yourself in a bit of hot water (pun intended).

As Prism said, the only time I know of that Dawn works the same as Synthrapol is as a surfactant...it makes the fabric more receptive to dye when dyeing...or to remove all coatings from fabric to prepare it for dyeing.

I use Bounce Color Catchers and I get them at the grocery store. I never wash before I complete a quilt. I like the what I call the crinkle/wrinkled look. I have never had any of my colors bleed onto each other