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Thompson Orient Red 1870 problems - Lindsey Owen

  • Trish White
    Leader
    November 21, 2014 11:14 AM EST

    I'm not using leaded enamels. I am paying close attention to the surface of my fine silver prior to the first firing of 2020 flux. when I apply thompsons orient red 1870 150 mesh, I am still getting fire scale. my trivets are clean. my kiln is clean. I am getting yellow edges but minimal fire scale with thompsons 1030 white, which tom Ellis recommended that I use. i put a layer of 2020 flux down before the 1030 as well. I am taking pieces out of the kiln before it gets to 1400 deg. I have success with other colors on fine silver. I am literally pulling my hair out and crying. this job has got to get done. someone please help. is it just impossible without leaded enamel?

    ANSWER FROM TOM ELLIS:

    You must begin to solve your problem by breaking it down in smaller parts.

    Is it the Enamel that is not good or is it possibly the flux?

    Take a 1 inch square of pure copper and clean very well - Sift the Orient Red directly onto the copper in an even coat - fire for 2 mins at 1450 and cool-

    If the Red comes out completely clean then it is NOT the enamel giving you a problem. If the enamel still contains specks of black then call Tom for replacement. He will also test a sample in stock and see if he has the same issues that you are having.

  • Trish White
    Leader
    November 21, 2014 8:44 PM EST
    ASK THE EXPERT - FROM Ricky Frank
    Hi Lindsey,
    I will try to provide a few thoughts on your question regarding your struggle with the 1870 red enamel.  I don't think I will solve your problem, but i will point out a few things.
    First of all, it is impossible to really know what is happening without seeing the piece and knowing exactly what steps have been taken, including time and temp, along the way.
    what do you mean by "paying close attention to the surface of my fine silver prior to the first firing"? This does not really provide us any information, other than you looked at it. 
    Next, i don't know what you are seeing that you are describing as "firescale". There is no firescale created when you fire on fine silver. firescale is the oxidation layer created on the surface  of metal when the copper has oxidized with the heat. it occurs with copper and sterling silver. with copper it can flake off or dissolve into enamel layers. with sterling silver it sits on the surface of the metal and creates a grey look to the silver. but it doesn't flake off. 
    The yellow you are seeing is most likely a chemical reaction caused by the white enamel touching or getting very close to the silver surface. like i said in regarding firescale and fine silver, you should be getting NO firescale with any color. I'm not really sure why you put the 2020 down before the 1030. was there a purpose to this? you would then be covering up a transparent layer of flux with an opaque white; for what purpose? 
    I'm assuming what you are referring to as "firescale" is some sort of "black" discoloration in the transparent red enamel> is this correct? I don't really know why this would happen, but my solution would be to problem solve it to see what you can change to get a different result. does the same thing happen with other transparent reds? what about if you use 2030 as first layer? are you married to having to use the 1870? why? what if the 1870 is fired over the same flux but a double layer (two thin layers), which could prevent the same type of chemical reaction which occurred with the 1030. sorry i cannot be more help but maybe this will get you thinking about what you are doing. Ricky Frank
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