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Thread: Silver melting problem

  1. #1
    Join Date
    Feb 2020
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    Default Silver melting problem

    Hello can anyone help please I am just setting up my own studio at home and trying to melt silver in a newly glazed crucible. I followed a video and glazed it myself for the first time as I have always used college equipment before. The silver melted easily but was floating in a pool of pale green clear liquid which then blocked the sprue when I poured I amm thinking it was probably the crucible glaze but how do I stop this from happening again ?

  2. #2
    Join Date
    Dec 2014
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    South Australia
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    Did you add borax to the melt? was this sand cast? sounds as though silver was not hot enough, sprue blocked, maybe it was too small or again the Silver was not hot enough, you need to keep heating the metal as you pour, if I can think of anything else I will add it
    Re the glaze did you allow it to solidify, this allows you see that it properly glazed
    Last edited by china; 21-06-2020 at 04:05 PM.

  3. #3
    Join Date
    Feb 2020
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    Just found it Thank you for replying.Yes I did add a small amount of borax to the melt heated it as I poured and poured into a sand cast Re the glaze I had let the glaze solidify but it seems to melt again when I heat the crucible I was left with a hard pool of greenish transparent glaze in the crucible bottom which I have remelted and poured out It made a green glassy lump. I’m nervous of trying again until I know what the problem is

  4. #4
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    Green is just the excess glaze should not be a problem, not too many people get right the first time it is a learning process, keep track of what you are doing, then if it is not successful you can back track and modify your process as I mentioned above if the sprue is too small the metal will solidify before it has flowed, did you include air expansion channels? a picture or two may help

  5. #5
    Join Date
    Aug 2019
    Location
    Oxfordshire
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    There are a few problems that occur regularly with the delft clay/sand casting which I and a number of others have come across. One of them is the sand is cold or rather room temperature so that when the metal hits the sand it cools and solidifies rapidly. There are a few things that can be done to minimise this:

    Keep the sprues short.
    Make the sprues as large a diameter as you can.
    Make sure the metal is hot enough. One of the differences between sand casting and investment/lost wax casting is that the investment is hot when the metal is cast into it probably around 700C so the metal will not cool so quickly. I have heard of people putting the delft moulds in the oven before casting into them, I don't know if there is any merit to doing this.

    I suspect your green flux in the sprue is a red herring. It is definitely unusual.

  6. #6
    Join Date
    Feb 2020
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    Thank you for the suggestions and apologies for late reply. Is there a way of being notified that someone has replied ? I poured off the excess green liquid and made my channels deeper and it worked a treat. Thank you ��

  7. #7
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    Feb 2020
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    Sorry for late reply I didn’t see you had posted until now Interesting re the sand temperature. I poured the excess green liquid out of the crucible this time before melting the silver and added more silver to add weight This seems to have worked ! Thank you so much for replying

  8. #8
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    Jul 2009
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    Quote Originally Posted by Helynwilder View Post
    Thank you for the suggestions and apologies for late reply. Is there a way of being notified that someone has replied ? ��
    Yes there is Helen, click on your Notifications (messages on the top right), general settings and click the button that says it will email you if you receive a reply to a thread you've started and save. That should do it. x
    Jules

  9. #9
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    Quote Originally Posted by Petal View Post
    Yes there is Helen, click on your Notifications (messages on the top right), general settings and click the button that says it will email you if you receive a reply to a thread you've started and save. That should do it. x
    How many years have I been onhere and I didn’t know that! Usually people just say no

  10. #10
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    Ahh, you learn something new on the forum every day Caroline, even if its something that's nothing to do with what you were looking for!
    Jules

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