mesh melt turn black

[Bonnie Rubinstein]

Hi- I am making mesh melts with system 96. Nothing dark, except some small pieces of aventurine green. The rest is firelight white, and light greens and blues, a few blue and green opaques thrown in. For some reason, sections of black result in the melt. It is not spalling- that is small flakes. This is the glass actually turning black, as if there was some incompatibility issue. ( I attached a picture, hope it shows up! ) Thanks for the feedback! Bonnie

[Bonnie Rubinstein]

the picture (clearly) was just a before shot of the stack of pre-fired glass.

[Brad Walker]

Got an after photo?

[Bonnie Rubinstein]

Ha- I broke it up with a hammer to use just the good parts and tossed the black. I will go to studio and see what I can get on a photo.

[Bonnie Rubinstein]

I recall I did take a quick pic prior to the hammer! here it is.

[DonMcClennen]

I actually see a lot of darker cathedrals in your pile... they will dominate!!!

[Bonnie Rubinstein]

a couple skinny cobalts and aventurines. So, they turn black? On a mesh melt, are light colors the only options?

[Brad Walker]

On a mesh melt, are light colors the only options?

I mostly use opaques and clears. Why would light colors be the only option?

[Judd]

I have had the exact same reaction using the exact same colors. I think the culprit is the transparent yellow. Whenever I do strip construction, or mesh melts, the area where the transparent yellow touches the blue will always darken.

When you stack the glass, place transparent above and below each yellow to minimize the blending, or tell your consumers that you MEANT to do it that way!!! YES! You meant to blend those colors, which explains the PREMIUM price!

[Bonnie Rubinstein]

hi all,
Thanks for the input.
I just spoke with Oceanside glass. Sent them the pics. This is the synopsis- I was working with reactive colors. Most of the time, at normal firing temps, this is not an issue . But at over 1600 degrees for mesh melts, this is.. the Copper based Blues and the Sulfur based Yellows react to make a deep burgundy and at higher temps, turns black. There you have it! So, they sent me a system 96 reactive chart: http://system96.com/Resources/System96ReactiveChart.pdf
This shows what colors are high to medium reactive, at the higher temps, even the medium reactives can get very dark.

So glad this is solved! Hope this helps others before they run into same situation.

Bonnie