Yellow Turns Black

[daisydog7]

Sometimes when I am making a flower, I'll use a yellow stringer and make a small dot, and when I take it out of the kiln, that yellow will no longer be yellow, it will be black! Some yellows seem to do this, and others don't. Am I doing something wrong, like getting it too hot, or what? This is beyond frustrating, not to mention a time waster. Any info would be so appreciated! Pam

[nagibeads]

Yellow reacts with alot of stuff and the edges turn black. I think this is because it has sulfur(?) in it. Work it cool and don't melt it in with a harsh flame. It may still get the black edges but it will not react over the entire yellow area. Someone please correct me if I am mistaken, but try to avoid using it for details when you are putting them next to colors that contain copper...

[daisydog7]

Thanks for the info. Does EDP contain copper? That is ususally what I use it next to.

[LauraT]

I don't know if EDP contains copper but I do know that it does not play nice with yellow. When I want to use yellow and any of the the pinks together I will lay down a small dot of clear then place the yellow over it.

[cadia]

Will Opal Yellow turn black if overheated too?

[Heidi von Frozenfyre]

This also happens if you are not on an oxy/L.P. torch. Try upping the oxy a little or lowering the L.P.

[RSimmons]

Originally Posted by daisydog7

Thanks for the info. Does EDP contain copper? That is ususally what I use it next to.

EDP appears to have lead and gallium in it, among other things.

Robert

[Peach Blossom Beads]

Originally Posted by RSimmons

EDP appears to have lead and gallium in it, among other things.

Robert

Where are you finding the info of what metal is in each color? Is there a chart somewhere like BE has? I'm pretty aggravated at myself right now b/c I misunderstood the info I was given and I've been worrying about lead this entire time (notice I'm pregnant). Thank God I have excellent ventilation.

Thanks for your help!

[RSimmons]

Originally Posted by taramag

Where are you finding the info of what metal is in each color? Is there a chart somewhere like BE has? I'm pretty aggravated at myself right now b/c I misunderstood the info I was given and I've been worrying about lead this entire time (notice I'm pregnant). Thank God I have excellent ventilation.

Thanks for your help!

I have on occasion done some analysis of a few different glasses as a part of some other work that I do. It is by no means a complete analysis of all of the ingredients, but the major components tend to show themselves. I haven't seen a chart of components for any of the Effetre/Vetrofond/Lauscha glass types - don't know if one exists.

Robert

[Peach Blossom Beads]

Thanks. I haven't seen a chart either, that's why I was wondering.

So what other colors have lead besides EDP and Trans Red? There has to be a way to tell based on the color or something (like when you can what has sulfur, what has gold, what has copper....). Any idea how to do that? Thanks.

[RSimmons]

Lead can be used as part of the flux as well as an additive to change the refractive index and dispersion of non-opaque glasses. That's why 'full lead crystal' is so colorful and sparkly. You can't tell by the color if there is lead present and assuming colorants based on the color of the glass can be misleading. There are many metallic compounds added to glass to change the color and working characteristics and lead is not the only one that can, under some circumstances, be toxic.

In general: Use good ventilation when working with glass, don't boil it in the flame, don't eat it. If you use basic safety rules it is not a problem.

Robert