Cloisonne Jewelry Techniques Enamels, Properties, Firing Times and Color Charts
by Patsy Croft
2 comments
Those Tiny Bubbles
Hi Patsy
I just took a look at your website and I think its an incredible idea for you! On the jewelry front, I have managed to make a very pretty (for my inexperience) and large pendant with a turtle, fish and starfish. For the past 2 weeks I have been creating a VERY large pelican pendant. I thought it came out o.k. but, every time I fire it now I see tiny air bubbles. I did use silver foil on copper and I must have had some air trapped in it. I’ll take some photos and send them in so you can give examples of what NOT to do.
Take care!!! 
Wendy
Thanks Wendy,
Your work looks great! Larger is better, gives you room to gradate colors. Your enamels are nice and shinny, as well as the clarity of the transparents.
You mentioned the bubbles, after 20 years I just read that the tiny bubbles are from underfiring. It is nice when you are not sure, as there are so many, many things that go on in the Cloisonne, art of enameling, that some one before has it documented.
Millenet states in his book, “Enamelling on Metal” from 1927
“ A few words of advice may not be out of place here. We have already said, and we repeat with emphasis, that it is essential that the furnace should be at its maximum heat at the moment of firing: and every enameller should take this axiom to heart: a short firing in a brisk heat.”
With winter here and we lose a lot of heat opening and closing the door, checking or replacing. Just one opening my heat will drop several hundred degrees. These tiny bubbles can be in one layer, just the one that was underfired. I am not saying fire at your kilns max. Our kilns are very different then 85 years ago. You have to experiment and find what temperature works best for you. The fun of enameling! Remember the one that was too hot and the base color bubbled up around the design.
I have one of those in my trunk!
Thanks for sharing, Patsy
Hi Patsy,
I’ve been running into this ‘tiny bubble’ problem in all of my attempts at transparent enamels, an area I’ve just started to tackle. The bubbles appear on copper, on foils, in FS plique a jour, on sterling sheet…everywhere. I’ve been firing at about 1500F, which /seems/ like it ought to be hot enough even for unleaded enamels (which I know fuse at much higher temperatures than their leaded counterparts.) Could I be causing this problem by applying the enamels too thickly, thereby causing underfiring even in a hot kiln? Or, should I really crank up the heat to 1620 like they did in the few classes I’ve had?* Or both?
Thank you!
Erin
*I assumed the kilns in class were kept that hot to keep up with the many students opening and closing the doors one after another.