Aniline dye questions

[Paul Prescott]

I've never used water soluble aniline dyes, but am dying to try them.

Most are sold in 1 ounce size, suitable for mixing in 1 quart of water. I know you can mix the powder to whatever "shade" you want, but my questions are:

1. If mixed to 1 quart, and partially used, how long is the remainder good for? IE, how long can the rest be stored in capped jars?

2. Does the stain settle out over time? If so, does heating and remixing always work?

Hope that's clear!
Any experiences appreciated!

[Steve Schoene]

I've found it had a very long shelf life--in the order of several years. It won't settle out of solution--its really dissolved, though new or old there may be a small amount that didn't dissolve so that it is a good practice to strain before using. I can't vouch for there being absolutely no color change over time, but if so it must be small from the samples I've kept. Of course, you would want to test the color on scrap.

[Todd Burch]

I have observed a color change over time with dyes I have manually mixed. I dyed some cherry a rich deep orange color (orange, some red, some yellow). I mixed more than I needed. A few months later, I went back to my mix and the color was quite a bit different. Not being a chemist, I hypothesize what happened over time is the colors actually blended MORE on their own, and became the true, actually muddy, color. However, when first mixed, it was a brilliant color.

Todd

[Steve Schoene]

It shouldn't be additional mixing, but it could be chemical change if the dye solution was in light a lot, was stored in a metal container, or if it wasn't mixed with distilled water initially. That is a good cautionary note about the need to make tests before assuming that there wasn't color change.

[Todd Burch]

It was stored in a (new) metal quart paint can. Good point! Didn't think of that. No mo metal.

Todd