Moldy Dye?

[Vilas Schroeder]

It appears that some transit dye I have mixed is starting to get mold on the top. I mixed the powder with 16oz distilled water and keep the mixture is plastic bottles. I heated the water in order to better disolve the dye, does the mold indicate I did not get it hot enough? Anyone else experience this problem?
Thanks

[Conrad Fiore]

It's a normal occurance. Here is an interesting read, http://web.mac.com/lubap/Working_with_Dyes/Care.html

[Prashun Patel]

Heat will kill bacteria and mold, but won't prevent it.

Once the temp cools, any open product with a lot of water and no antimicrobial agent will foster mold and bacterial growth.

You either have to seal and refrigerate the jar, or use alcohol instead of the water. The alcohols we typically use @ home contain about 5% water, but the alcohol is enough of a deterrent to prevent mold growth for a while. These are quite volatile, though, so they're best stored in a sealable, nonmetallic container. Polyethylene (unless it's high-density) is a bad choice. Glass is a good choice.

Sunlight will also discourage mold growth, but ironically, will cause the dye to fade over time.

The bottom line for me with Transtint is to mix up as little dye as possible, and then either discard the rest or save it only for scrap projects where exact color preservation is not critical.

[Scott Holmes]

That's a good reason to do as I do...use dyes in denatured alcohol.

[Chris Fournier]

In about 20 years I've had one small jar of dye go moldy and I've used gallons of the stuff and stored odd colours for well over 10 years in some cases.

You used distilled water and that is key. The other issue is the jar that you used. I sterilize the jars that I use for dyes and have never had a mold problem since. I suppose that dipping dirty rags into the dye could introduce the microbes required to grow mold too...

Alcohol for dyestains is all good and well if you are spraying but water rules if you are hand applying stains and want maximum working time with the colour.