My attempt at a cobalt blue marble cane went totally wrong

I mixed the batch at 2200 degrees like usual, but the color came out this weird murky purple instead of the deep blue I wanted. Turns out my old batch of cobalt powder from the Portland supply shop had some moisture in it, which messed with the chemistry. Has anyone else had color issues with stored powders, and how do you keep them dry?

3 comments

3 Comments

joelt701mo ago

Stored powders can be so finicky!

hugomurray1mo ago

@joelt70, you're not wrong. What kind of powder are you dealing with? I've seen stuff like flour or drywall compound just suck moisture right out of the air and turn into a brick if the lid isn't on perfect. Other times, things like spackle will skin over in the bucket after you open it once. It's a constant fight against clumps.

the_simon1mo ago

Yeah, that moisture thing is a killer. I had a batch of copper carbonate go greenish-brown on me once from the same problem. Now I keep all my color powders in big glass jars with those silicone seal lids. I throw a couple of those little silica gel packets you get in shoe boxes right in the jar with the powder. It sounds simple, but it made a huge difference for me.