Anyone know why my gold foil turned black under the enamels (transparent, lead-bearing; Reds, Pinks, Blues, Greens, Aquas, Yellow) I was testing?
I first fired a layer of transparents and then fired foil on that layer, at 1450 degrees F. Then fired transparents over that. Black. So I re-fired at 1500 F. Still black.
The silver foil I was testing on the same tiles with the same colors looks lovely.
Have you ever used this gold foil before?
“Gold” covers a lot of ground. I suspect it’s not 24K, which won’t tarnish or turn black when you use it for enameling. Even 22K will tarnish unless you depletion-guild it first. Where did you purchase this foil? What does the package say?
I have heard salts can turn it black. Try looking in Google for “turning gold foil black with salt”.
Steve
I strongly suspect an alloy ingredient in the gold foil. I have always rolled my own foil from 24ct gold grain, and had no problem.
Hello All, RE: the misbehaving foil I mentioned awhile ago. 1. Fortunately I did not lose any work, since I was just testing some colors that I will be using in a work that I am currently planning. Whew! 2. I have had these books of gold sheets for years and needed to test them. 3. So, after feeling quite despondent that the gold I used from one of those sheets had turned black when fired (and appeared blue and green once I fired a layer of b or g over them. . . wild, huh), I gather my mood together and did a separate test of gold from each book of gold sheets. 4. Satisfaction: two of the samples retained their brilliance under transparent enamels; the remaining samples turned and remained dark grey-ish black. So. . . I am happy to have some, sadly limited quantities, that I can use with enamels. The uncooperative (LOL) gold, I am guessing is leaf and not suitable for enameling. I will find other uses for that huge amount of gold. I do not believe these are alloys of gold or brass leaf. So. . .onward!