WarmGlass.com

Hi Everyone, I have attached a rather grainy photo to show the problems I'm having problems with a spectrum glass colour lemon grass. When it went into the kiln to slump, it was fine, when it came out of the kiln, only the lemon had the red colour splotchy contamination. It is only on the surface as I can sand it off. Just wondering if there is something I can do to avoid this. This seems to happen frequently with this colour. The splotchy red is on the underside too, but only on the lemon, the other colours are fine.
Thanks, Aileen

Use Bullseye . . .

If the nearest bullseye distributor wasn't 1000 kilometres away, I probably would use it.

lemongrass contains sulfur, many Blues contain copper. Are you sure it's not just a (edited) *reaction* (not reason) between the two?

(hard to tell from the photo)

Dana

Thanks Dana, I would imagine that is the problem. Do you know any way to mix those colours without having the contamination problem?

It looks like a reaction to me, too. The way to prevent it is to put something between the reactive colors--where they touch the chemicals in the glass are reacting to form a new compound, which can be grey/brown/black/rust/etc.

You can use a thin layer of clear powder, a sheet of clear (or some other color) or something similar. Please note that for the MOST reactive colors, especially the glasses that are designed to react hugely (such as Bullseye's Reactive series), a thin layer of powder won't work--outgassing from the nearby glass can be enough to set off the reaction. But for most colors, the little powder layer is sufficient.

Thanks Cynthia, everyday is a new learning day!