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Sanodol Blue Dye

I am using Sanodol Blue dye and after a while it seems to break down, that is, there are particles in the dye and it goes "slimy" at the bottom and sides, and there appears to be small bacteria growths on the top, I use de-ionized water, hoping someone can set me straight here.

Pete Barsden
Blade manufacturer - Perth, Western Australia
2006

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First of four simultaneous responses --

It's always good practice to pump/filter dyestuffs. Keeps the bath cleaner, and keeps circulation for even heating.

Marc Green
anodizer - Boise, Idaho
2006

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Second of four simultaneous responses --

Welcome to the evils of blue dye. Talk to your vendor about cures. If I remember correctly, it involves taking it to a relatively high temp for half an hour , cooling and filtering. There materials sold to either kill it or to prevent the growth.

James Watts
- Navarre, Florida
2006

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Third of four simultaneous responses -- 2006

Blue scales, huh?
How hot is your dye? Algae have been know to enjoy a dye or two before.
Try raising your temp.

Bill Grayson
metal finishing - San Jose, California, USA

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Fourth of four simultaneous responses -- 2006

Yeast or another fungus is growing in the dye solution. Dump the present solution, then clean and sterilize the tank (hydrogen peroxide or chlorine bleach [adv: bleach/sodium hypochlorite in bulk on eBay or Amazon] ). Rinse well to remove residue. Cover the new solution when not in use and either occasionally heat to near-boiling or use a biocide to avoid future fungus growth.

Ask your dye supplier to recommend a suitable biocide. Probably an isothiazolinone compound such as benzisothiazolinone or octylisothiazolinone.

Ken Vlach [deceased]
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.