My attempt at a cobalt blue implosion went totally purple instead

I was working with some new frit from a supplier in Portland, and the color shift under the flame was wild. Anyone have a go-to cobalt that actually stays blue?

3 comments

3 Comments

martinez.ryan5mo ago

Wait, that Portland frit is known for doing that? I had no idea some suppliers had glass that reactive. What else does it do, just turn blues purple or does it shift other colors too?

jessesingh5mo ago

Blame the glass, not the cobalt. That Portland frit is known for its reactive chemistry, which can push blues into purple territory. You might just need to adjust your flame chemistry to keep it where you want.

margaret992mo agoProlific Poster

Those Portland frit batches from around 2018 are especially bad for this. I remember a big batch that went out had some weird manganese contamination in the silica that really messes with the color stability across the board, not just blues. The issue is that frit is basically recycled glass sometimes, and the quality control on the source material can be spotty depending on the supplier. If you're seeing purples show up where you want straight blue, it's a good bet the frit itself has some extra metal content that got stirred in during production. Sometimes switching to a different batch number from the same company fixes it completely, so it's worth a call to your rep to ask what lot they're shipping now.