Q: Enameling opaque white on sterling - turns green and pink ?!

Hi,

so trying to have clean white on sterling (champleve style) but every opaque white turns pink (a bit of green where sterling and enamel meet, and it spreads from there as pink) especially 2nd and later firings.

Process
Sterling depletion guilded 7 times with torch, 5mins in strong hot citric acid in ultrasonic in between, lastly even tried degreasing salts with electroplating equipment. Looks fine and white.

Enamels, lead bearing and lead free from Milton Bridge, WG Ball and Thompson tried.

Best whites are of course on trivet (stainless steel) where some enamel has dropped :slight_smile:

Temperature as recommended around 790C / 1450 F, 1-2 minutes. Not mush color problem at orange peel level.

Cannot use fine silver due softness… Any hints?

First fire a layer of hard clear enamel?

Tony Konrath

tonykonrath@mac.com

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Discussing your situation with my enameling group Enameling Group South, which includes many respected teachers of enameling, agreed your depletion was not the problem. The firing temperatures are spot on. Tony Korath’s suggestion was seconded by the group and usually used when there is a recess and a side edge to be filled. Edges tend to be problematic… Unfortunately enameling has a way of doing the unexpected. They also recommended testing a softer fusing white vs a harder fusing white which most manufacturers make. A wise suggestion is to call Tom Ellis at Thompson Enameling and discuss it with him.
Dick Bugdal

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Yes, been thinking along these lines. I don’t have hard flux at the moment but will experiment soon with hard white first layer with as fast as possible (slightly orange peel = minimum color problem) and on top layers of softest white I have. Let’s see…

Keep us informed…but try the flux which does make a difference.

Tried three different clear fluxes, medium, hard and special one for silver…all turned ugly GREEN in first firing! There is something strange going in my process, or with silver, but that’s unlikely, tried sterling and Continuum with similar results.

Well, even green flux helps actual enameling process a bit, perhaps allowing one extra firing before color problems starts to crawl to surface. But not enough.

But there must be something I can do, clear flux must mean clear for other people. I will try neutralizing silver better after depletion gilding, have not used baking soda yet (but have used saliva). Other that that I start to be out of ideas.

Here is example of two different whites, and “beautiful” clear silver flux in the middle. Two firings, 760-790C, 2 mins.

Whites are not yet too bad, but pink starts to show up on corner areas. I think clear flux should never look like that, should it?

I wonder if you might not be depletion gilding enough to get a true fine silver layer. It seems that the enamel might be reacting to a alloy in the sterling. Some companies add more than just pure fine silver and copper. Try experimenting on a piece of pure fine silver to see if you are getting the same reaction to rule out a contaminant in your sterling. Best of luck!

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Did you ever call Tom Ellis at Thompson Enamel and discuss the issue with him? Are you using leaded enamels or non leaded enamels? As I am not familiar with green flux can you tell us which brand of flux you are using. Thompson Enamel has been manufacturing enamels for the artists but more so for the industrial uses as coating refrigerators, signs for over 119 years so they do have the expertise. Here is their website link…https://thompsonenamel.com.

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